bluuebunny/crossref_metadata_2025 huggingface dataset:
The competence of teachers based on academic qualification and gender
Authors: Marjon M , Nugroho K U Z
Published: October 2019

The study aims to determine the competency map of Bengkulu City Junior High School (SMP) teachers based on age, class and gender. This research is the research of Junior High School teachers in Bengkulu City. This study is a survey with a sample of 157 mathematics teachers at SMP Bengkulu City Year 2015.The result of this study is the level of Graduation for Bengkulu Junior High School teachers only 64.97% graduated, and 35.03% did not pass, it shows that the completeness of SMP Teacher competence in Bengkulu City has not been reached. The percentage of UKG graduation rate in 2015 for junior high school teachers in Bengkulu City when reviewed by sex is that the junior high school teacher in Bengkulu city has male gender as many as 63.83%, and female is 65.45%. The average score of SMP Teacher competence in Bengkulu City based on academic qualification (≤D3, D4 / S1 and S2) is 52.51; 58.84 and 69.21. This indicates that the average score of competence of teachers who have academic qualification of S2 has the highest score and the teacher who has the lowest D3 qualified has the lowest score, even under the passing grade that must be achieved.
Implementation design of monitoring attendance for teacher at elementary school with scattered location
Authors: Yulianingsih Y , Niswati Z , Rangka I B , Marti’ah S
Published: October 2019

The current location of educational institutions is generally not in the same location due to lack of land availability or educational institutions has the goal of accommodating a number of students from certain regions equally, in other words expanding the reach of these educational institutions. Generally, the institution will provide a solution by constructing a number of rooms vertically and grouping them based on the type of activity given. But the impact is the difficulty of monitoring business administrators and students when they want to conduct guidance or face-to-face counselling in addition to the teaching schedule. Thus it is deemed necessary to have a monitoring instrument regarding the presence of teachers to facilitate students and school administrators to monitor their existence. The system development method was designed using Rapid Application Development (RAD) based on observations of bourding-based elementary schools in Bogor, West Java. The system is designed based on the needs of students and business administrators, through the system there will be a number of information about teacher attendance, substitute staff, the location of the teacher’s existence, current activities and other planned activities so that the parties can optimally utilize the information. With this instrument it is expected that students can learn to manage time effectively so that the character of students who are devoted, knowledgeable, skilled, independent and able to adapt to the development of information technology are formed.
Profile of elementary school teachers’ ability in analyzing higher order thinking science question
Authors: Atmojo I R W , Tiana R , Karsono K
Published: October 2019

The purpose of this research was to analyze the ability of profile teachers from elementary schools. The subjects were 8 teachers taken from 14 teachers in Elementary School in Philippines and 8 teachers taken from 15 teachers in Elementary School in Central Java, Indonesia. This was a descriptive quantitative research. The instrument used had 15 items with HOT Levels that were comprised of C4 (Analyze) represented in 5 items, C5 (Evaluate) referring to 5 items, and C6 (Create) referring to 5 items. The result showed the level that could be analyzed by the teachers whereby C6 level could be analyzed with the highest percentage of 58.3%, and C4 level could be analyzed with the lowest percentage of 48.6%. Based on the result, it could be concluded that in analyzing HOT questions the Philippine teachers could analyze the questions correctly with the percentage of 81%, and Indonesian teachers could analyze the questions correctly with the percentage of 79.8%. The teachers from both schools were classified in the good category in analyzing the HOT science materials.
Spatial sense instrument for prospective elementary school student
Authors: Putri H E , Isrokatun I , Majid N W A , Ridwan T
Published: October 2019

In order to produce high-quality research, the good instrument is required. The instrument developed in this study was a spatial sense test instrument. The test items were based on indicators of spatial sense. After prepared the test items then tested to determine the validity, reliability, level of difficulty and distinguishing power. The results show that the questions were compiled for this study generally has a high validity, reliability is very high, distinguishing power for each items is well, and the questions are divided by varied level difficulty (easy, medium and difficult). Based on this result, it can be concluded that the spatial sense test items that developed can be used as a test instrument for future research.
Developing mathematical investigative attitudes of prospective primary school teachers
Authors: Maulana M , Hanifah N , Aeni A N , Julia J , Syahid A A
Published: October 2019

Investigation activities are inevitable in mathematics learning. Hence, students are expected to perform their investigative attitude during their mathematics learning to achieve the learning objectives. This study aims at determining the effectiveness of the use of MURRDERR (metaphor, understand, recall, recognize, detect, elaborate, review, and respect) strategy in developing the investigative attitude of prospective primary school teachers. The research method with didactic and quasi-experimental designs was applied to 119 prospective primary school teachers. Instruments in the form of initial and final attitude scales were used to obtain respondents’ investigative attitudes data. The results showed that MURRDERR strategy was effective in developing mathematical investigative attitudes, especially in terms of: discussing strategies for solving problems; trying new ideas; choosing systematic ways; noting important things; working freely and jointly; asking to acquire solution strategy; and being curious about presumption before they were proven. Based on these results, it could be concluded that MURRDERR strategy could be used as an alternative learning to develop mathematical investigative attitudes.
ICT competences of primary school teachers
Authors: Syahid A A , Sunarya D T , Sudin A , Sunaengsih C , Karlina D A
Published: October 2019

One of the traits of professional teachers is to possess good pedagogic competence. Primary school teachers in Indonesia are required to possess good pedagogic competence and to integrate technology into learning processes. Primary school teachers should be able to utilize Information and Communication Technology (ICT) in teaching process. The present study yields a pedagogic competence and classroom management profile of primary school teachers. This study employs survey method to obtain data from primary school teachers. Data is processed using percentage calculation and descriptive analysis. The result of analysis shows that the number of primary school teachers who possess good pedagogic competence is only less than half (32%). They only do conventional classroom management and have not optimally utilized ICT for learning activities in primary schools. Thus, this paper will discuss the importance of ICT competence and how to develop it for primary school teachers.
The development of digital video applications for deaf students
Authors: Kurnia R A M , Hakim D L , Ana A
Published: October 2019

The purpose of this study was to obtain a picture of the development as well as determine the practicality and effectiveness of digital video applications for deaf students. This research method usinganalysis, design, development, implementation, and evaluation (ADDIE).The study was conducted in extraordinary high school part B Ciamis. Samples are deaf student’s as many as five people. Data collection technique used observation, interview and assessment skills. The assessment process digital video applications is done by three expert judgment namely media experts, expert learning materials, and expert skills that the results show that the development of digital video applications for deaf students should pay attention to several aspects, namely, the speed of time, materials selection and image objects, font selection and color for the text narration, and must match the content of learning materials so that they can help students to gain an understanding in terms of both theory and practice. The result of the development of digital video learning applications for deaf students This has advantages that make it easier to understand the deaf students are with their material content direct overview and explanation in the form of narrative text and sign language so as to make a special attraction for the students to learn. This digital video applications can help replenish the skills for deaf students in the classroom so that learning is not only with the conventional method.
An Efficient Group Key Transfer protocol for Secure Encryption
Authors: Murthy A.V.V.S. , Reddy P. Vasudeva
Published: October 2019

Cryptography algorithms provide confidentiality, integrity and authentication of communication channels. These algorithms and protocols are based on sophisticated mathe-matics such as computational and algorithmic algebraic geometry, coding theory, and generic algorithms for finite abelian groups. For secure encryption, establishing or transferring a shared key between the parties is an interesting challenge. Key management is an essential crypto-graphic primitive upon which other security primitives are built.

In this paper, we present a generic construction of asymmetric key Group key transfer protocol using one way function and coding theory technique. By guaranteeing the freshness of authentication messages, the authenticity of the generator of authentication messages and the completeness of the authenticator, the improved protocol can resist various passive and active attacks. The protocol allows the participants in the group to derive a common encryption key, provide the key security and unknown key share properties. Security analysis of proposed scheme is also discussed.
Wave propagation in layered poroelastic cylinder in contact with fluid
Authors: Nageswaranath C , Kumar J Manoj , Shah S Ahmed , Apsar G
Published: October 2019

The present paper investigates the propagation of time harmonic waves in a two layered hollow poroelastic cylinder in contact with inviscid fluids. The hollow poroelastic two layered cylinder is assumed to be infinite in axial direction. The outer and inner surfaces of the two layered cylinder are in contact with fluids and at the interface stresses and displacements are continuous. The frequency equation for wave propagation for a pervious is obtained. Non-dimensional phase velocity is computed as a function of wave number and presented graphically for two types of two layered cylinder for arbitrary parameters of the fluid in contact. Numerical results show that, in general, phase velocity is more in absence of outer fluid compared to the case of absence of inner fluid. Several other particular cases are discussed.
Optimal crop water allocation coupled with reservoir operation by Genetic Algorithm and Non-Linear Programming (GA-NLP) hybrid approach
Authors: Leela Krishna K , Umamahesh N V , Srinivasa Prasad A
Published: October 2019

This paper presents a Genetic Algorithm and Non-Linear Programming (GA-NLP) hybrid model to derive steady state optimal reservoir operating policies for a reservoir. In the present study, the objective is maximizing the yields of all the crops in the command area considering yield response to water deficit subject to constraints on reservoir water balance, storage bounds, channel capacities and minimum water requirements. Decision variables of the model are fortnight water allocations to each crop grown under left & right main canals and d/s releases. The model developed is applied to the Nagarjunasagar reservoir in Andhra Pradesh, India. Various levels of dependable inflows entering into the reservoir (75%, 80% & 85%) are considered in the present study. Optimal policy obtained by proposed model are validated through simulation and compared with Standard operating policy (SOP). The results obtained using the proposed model gives guidelines to reservoir managers to take decisions. Results reveal that GA-NLP model can be effectively used for optimal allocation of limited available water resources to any reservoir.
Characterization of Minimal distributive semi lattice.
Authors: Ravi Kumar E Sri Rama , Rao M Venkateswara
Published: October 2019

In this paper we give some characterization of minimal distributive semi lattice and proper filter in directed above semi lattice. Also this manuscript illustrates several principal results concerning congruence kernels of minimal distributive semi lattice S and provides a necessary and sufficient condition for a semi lattice congruence ≡ on Sis a * congruence. And also established a necessary and sufficient condition of an ideal of minimal distributive semi lattice S is a kernel ideal of semi lattice S.
Numerical solution of singularly perturbed delay differential equations using gaussion quadrature method
Authors: Phaneendra K , Lalu M
Published: October 2019

In this paper, a quadrature technique is employed for the solution of singularly perturbed delay differential equation. A first-order neutral type delay differential equation is achieved, which is asymptotically equivalent to the given singularly perturbed delay differential equation. Then Gaussian quadrature two-point formula is implemented on the first order equation to get a tridiagonal. Thomas algorithm is used to solve the resulting tri-diagonal system. The proposed method is implemented on model example, for different value of delay parameter and perturbation parameter. Maximum absolute errors are tabulated with a comparison to authorize the method. Theoretical convergence of the method is discussed. The layer behaviour is discussed using the graphical histrionics.
Reliability of Time - Dependent Stress - Strength System for Finite Mixture of Exponential and Pareto Distribution under Different Cycles
Authors: Ashok P. , Swathi N. , Devi M.Tirumala , Maheswari T.SumathiUma
Published: October 2019

In this paper general expression of reliability has been derived for time dependent stress strength model if stress is random independent and strength is random fixed for the following cases. (i).Stress follow Pareto distribution and strength follow finite mixture of exponential distribution. (ii).Stress follow exponential distribution and strength follow finite mixture of Pareto distribution.
The study of double stratification and viscous dissipation effects on chemically radiative MHD free convective flow of micropolar fluid embedded in non-Darcian porous medium
Authors: Reddy K. Jayarami , Reddy M. Narendradh , Ramakrishna K.
Published: October 2019

Numerical expression for steady 2D natural convection magnetohydrodynamics flow of micropolar fluid past along a vertical surface embedded through non-Darcian porous medium in the presence of heat source, chemical reaction, viscous dissipation and thermal radiation is obtained. Variable wall temperature and concentration in a doubly stratified are taken into account. The initial governing boundary layer equations are transformed to a system of ODEs, which are then solved numerically by using the Runge– Kutta–Fehlberg fourth–fifth order method along shooting technique. A parametric study is conducted and so that numerical result are obtained for the velocity, micro-rotation, temperature and concentration as well as the local friction factor coefficient, local couple stress, local Nusselt and Sherwood numbers for different values of the governing parameters, namely, the magnetic parameter, material parameter, Prandtl number, radiation parameter, chemical reaction parameter and viscous dissipation and discussed in detail. Comparison in limiting case is also part of present study to validate the obtained results.
On Soft Ternary Γ-Semirings-I
Authors: Kumar B. Ravi , Rao B. Sankara , Rao D. Madhusudhana , Prasad P. Siva , Vasantha M.
Published: October 2019

In this paper with the help of soft set theory the notion of soft ternary Γ-semiring and soft ternary Γ-sub semiring are introduced. Some of the properties of soft ternary Γ-semiring are discussed and some illustrations are also given. It is proved that (1) a soft set (q, P1, Γ) over a ternary Γ-semiring T is a soft ternary Γ-semiring over T if and only if for all x ∈ P1; q(x) ≠ Ø a ternary Γ-subsemiring of T. (2) A soft set (r, P1, Γ) over T is a soft L(R, M) Γ-ideal over T iff ∀ p
1 ∈ P1; r(p1
) ≠ Ø is a L(R, M) Γ-ideal of T. (3) Let (q, P1, Γ) and (r, P2, Γ) be two soft ternary Γ-semirings over T, such that P1 ∩ P2 ≠ Ø Then (q, P1, Γ) ∩r(r, P2, Γ) is a soft ternary Γ-semiring over T. (4) Let (q, P1, Γ) and (r, P2, Γ) are two soft ternary Γ-semirings over T, such that P1 ∩ P2 ≠ Ø Then (q, P1, Γ) ∪E(r, P2, Γ) is a soft ternary Γ-semiring over T. (5) Let (q, P1, Γ) and (r, P2, Γ) are two soft ternary Γ-semirings over T. Then (q, P1, Γ) Λ(r, P2, Γ) is a soft ternary Γ-semiring over T. (6) Let (q, P1, Γ) and (r, P2, Γ) are two soft ternary Γ-semirings over T. Then (q, P1, Γ) Λ(r, P2, Γ) is a soft ternary Γ-semiring over T. (7) Let (q, P1, Γ), (r, P2, Γ) and (s, P3, Γ) are any three soft ternary Γ-semirings over a commutative ternary Γ-semiring T. Then (q, P1, Γ) ⊚(r, P2, Γ) ⊚(s, P3, Γ)is a soft ternary Γ-semiring over T. (8) Let (q, P1
, Γ), (r, P2
, Γ) are any two soft Γ-ideals over a ternaryΓ-semiring T with P1 ∩ P2 ≠ Ø Then (q, P1
, Γ) ∪R (r, P2
, Γ) is a soft Γ-ideal over T contained in both (q, P1
, Γ), (r, P2
, Γ). (9) Let (q, P1
, Γ), (r, P2
, Γ) are any two soft Γ-ideals over a ternary Γ-semiring T. Then (q, P1
, Γ). E (r, P2
, Γ) is also soft Γ-ideal over T contained in both (q, P1
, Γ) and(r, P2
, Γ).

In section 5, the term soft ternary Γ-sub semiring is introduced and some examples are given and characterized the soft ternary Γ-semirings.
Modified Taguchi Approach for optimizing the process parameter using the fictitious parameter
Authors: Charan Kumar G , Varalakshmi M , Tiwari Ankita , Rajyalakshmi K.
Published: October 2019

Taguchi approach is adopted to optimize the process parameters and improve the quality of components that are manufactured. Nature of the output response in any scientific investigation has to be understood through experimentation prior to the development of a suitable mathematical model. When several input variables are involved in the scientific problem, it is very difficult to develop a relation between the output responses in terms of input variables. The objective of this paper is to determine the expected range for the process parameters in the optimization process by introducing fictitious parameter.
Optimal strategy analysis of N-policy Two-Phase M/Ek/1 Vacation Queueing system with Server Start-Up, Time-Out and Breakdown
Authors: Rao A Ankamma , Devi V N Rama , Chandan K
Published: October 2019

This article presents optimalstrategy N-Policy M/Ek/1 vacation queueingsystem when the server is in Start-up, Time-out and Breakdown for two-phase. The individual arrivals considered to follow Poisson process and receive batch service of k-stages in the first phase, individual service in the second phase. During the service arrivals are allowed to enter the batch. On completion of the second phase service to all customers in the second phase, the server come back to the first phaseand do the service to the customers who have arrived by providing them first phase service of k-stages followed by second phase service. If there is no customer waiting in the phase one service, the server waits for a fixed time ‘C’ is called server Time-out. If units arrived during this fixed time, then the server provides first phase followed by second phase service, otherwise after expiration of fixed time he takes a vacation. After N-customers accumulate in the system the server returns from vacation. Before going to first phase service, the server spends a random startup period for pre-service after coming back from vacation. During individual service the server is susceptible to random breakdown according to a Poisson process and the repair time follows an exponential distribution. After repair the server resumes individual service. Exact notations for steady state distribution of the number of customers in the system are derived. Developed a cost model for determining the optimal operating policy at a minimum cost. By using numerical illustrations the sensitivity analysis is also presented.
Bianchi Type-III Dark Energy Cosmological Models in Brans-Dicke Theory of Gravitation
Authors: Neelima D , Rao V U M
Published: October 2019

Dark energy cosmological models with variable equation of state (EoS) parameter in Brans-Dicke [1] scalar tensor theory of gravitation are obtained. The field equations have been solved by using the anisotropy feature of the universe in Bianchi type-III metric. Some important features of the models, thus obtained, have been discussed. We noticed that as a special case, it is always possible to obtain dark energy cosmological models in general relativity.
Prey Predator Dynamics in Three Species Ecological Model
Authors: Paparao A.V , MurtyGamini N.V.S.R.C.
Published: October 2019

In this paper we proposed a three species Ecological model with a Prey and Two predators. Distributed type of delay is incorporated in the interaction of prey and second predator is taken for investigation. The system dynamics is studied at its interior equilibrium point with exponential type of delay kernel. The effect of Time delay on the dynamical behavior of the system is studied using Numerical simulation. It is shown that the delay arguments with different weight parameters exhibit rich dynamics and the system is asymptotically stable.
Non-Static Plane Symmetric Dark Energy with String Cosmological Model in Self Creation Theory
Authors: Vinutha T , Shekar B Raja , Satyanarayana G
Published: October 2019

In this paper we have investigated the non-static plane symmetric model in the presence of dark energy and one dimensional cosmic string in the frame work of Barber’s second self creation theory by using hybrid scale factor. We have discussed some physical and geometrical properties of the obtained model such as spatial volume(V ), deceleration parameter (q), expansion scalar(θ), Hubble parameter (H), shear scalar (σ), anisotropic parameter (Ah
), EoS parameter (ωde
) and the state finder parameters (r, s). Here we have observed that our model is compatible with the present day cosmological observations.
Kantowski-Sachs bulk viscous string cosmological model in f(R) theory of gravity
Authors: Prasanthi U.Y. Divya , Aditya Y.
Published: October 2019

The present work deals with a spatially homogeneous and anisotropic Kantowski-Sachs space-time filled with bulk viscous fluid, containing one-dimensional cosmic strings. To obtain a deterministic solution of the field equations, we used the assumption of shear scalar is proportional to expansion scalar of the model. We have investigated geometric and kinematic properties of our bulk viscous string model and discussed the role of bulk viscosity in the evolution of Kantowski-Sachs universe within the framework of f(R) modified theory gravity. A detailed physical discussion of the dynamical parameters is presented through a graphical representation.
Some New Results on Pythagorean Fuzzy Matrices
Authors: Silambarasan I. , Sriram S.
Published: October 2019

In this paper, we define an operation on Pythagorean fuzzy matrices (*) and discuss their properties in relation with standard operations available in the literature. Also, we prove some new results on Pythagorean fuzzy matrices. Further, we prove equalities and inequalities of Pythagorean fuzzy matrices.
Analysing electricity demand in neighbourhoods with electricity generation from solar power systems: A case study of a large housing cooperative in Norway
Authors: Sørensen Åse Lekang , Sartori Igor , Lindberg Karen Byskov , Andresen Inger
Published: October 2019

An energy management system can be introduced on a neighbourhood level, to achieve energy goals such as increased self-consumption of locally produced energy. In this case-study, electricity generation from photovoltaic (PV) systems is simulated at Risvollan housing cooperative, a large housing cooperative in Norway. The electricity generation from PV systems of different orientations and capacities are analysed with the electricity load. Key performance indicators (KPIs) such as self-generation, self-consumption and generation multiple are described, based on hourly values. The electricity generation from the south-oriented building façade PV systems are about 5-6% higher than for the east-west oriented rooftop PV systems on an annual basis, since the façade PV systems generate more electricity in the spring and autumn. The self-consumption factor is the most important KPI in Norway, due to the national tariff structure. For the total housing cooperative, a PV capacity of about 1,000 kWp seem suitable, giving a self-consumption factor of 97% for a rooftop system, based on 2018 electricity and climate data. From the perspective of the housing cooperative, it is financial beneficial to aggregate electricity loads for common areas and apartments, since a higher share of the electricity can be used by the cooperative. For this to be possible, also housing cooperatives with PV must be facilitated for in the prosumer agreement. Comparing a single 1,100 kWp PV system providing electricity to the total cooperative with 22 PV systems of 50 kWp behind 22 garage meters, the self-consumption factor decreases from 95% to average 14%, resulting in a 41% lower financial value for the PV electricity.
LCA of the Zero Emission Neighbourhood Ydalir
Authors: Lund K M , Lausselet C , Brattebø H
Published: October 2019

Buildings represent a critical piece of a low-carbon future and their long lifetime necessitates urgent adoption of state-of-the-art performance standards. So far, LCA studies have assessed buildings, mobility and energy systems mainly individually. Zero Emission Neighbourhoods (ZEN) give a unique chance to combine these elements. In Norway, the Research Centre on ZEN has as a goal to enable the transition to a low carbon society by developing sustainable ZENs.

In this study, a LCA model for neighbourhood based on a modular structure with five physical elements; buildings, mobility, infrastructure, networks and on-site energy was applied on Ydalir, a pilot project of the ZEN Centre. Revealing that regardless of which scenario considered, the ZEN Ydalir does not achieve their ambitious goal of zero emissions. Further, the results show that the operation of mobility is a major source of the total greenhouse gas (GHG) emissions, accounting for 21-46%. Considering the life cycle stage materials, buildings are the largest contributor representing 24% of all GHG emissions. Thus, these two areas have been highlighted as the best options for improvement. Parameters related to uncertainties or are large contributors to the environmental impact are included in a sensitivity analysis.
Microclimate analysis of a university campus in Norway
Authors: Brozovsky Johannes , Corio Sara , Gaitani Niki , Gustavsen Arild
Published: October 2019

Climate responsive urban design that makes use of passive heating and cooling strategies and enhances pedestrian comfort is a key element to a sustainable society. Knowing the impact of different materials, building typologies and arrangements and a building’s sensitivity to microclimatic conditions, the energy balance can be enhanced. This study aims to evaluate the microclimatic conditions at the campus of the Norwegian University of Science and Technology, located in Trondheim, Norway. A numerical model was used and validated with punctual measurements on site. The results for air temperature showed a considerable seasonal variation with highest spatial temperature differences in summer and lowest in winter. Regarding the analysis of the wind field, east-west passages were identified as problematic. The influence of the seasonal changing leaf area density of the vegetation had a visible but minor influence on the wind field. The calibrated model will be used for further research on the influence of new building bodies on microclimate and thus building energy demand and pedestrian comfort.
Comparison of different measures for reducing the carbon footprint of the building sector – a rental house case study
Authors: Holopainen R , Ahola R , Bergbom K , Vaarala H
Published: October 2019

This paper compares and estimates cost-optimal means to increase the potential of reducing the carbon footprint of future rental houses. As a case study we present a comparison between four rental apartment houses, where one house has achieved the Nordic Swan ecolabel. The carbon footprints of these buildings have been calculated for the building lifetime. According to the results, the effects of single measures are quite small in reducing the carbon footprint, but larger effects can be obtained by combining several measures together. It is essential to minimize the amount of used materials by paying attention to material efficiency under both design and construction phase. The paper also discusses the role of the voluntary ecolabelling of buildings as a tool to reduce the carbon footprint of the building sector.
Towards low carbon economy – green bond and asset development
Authors: Nenonen S , Koski A , Lassila AP , Lehikoinen S
Published: October 2019

Green Bonds are an instrument for driving the environmentally friendly and low-carbon economy. Green Bonds are bonds whose proceeds are earmarked for and transparently channelled to environmentally-friendly projects and activities. The real estate industry has a multi-decade track record of addressing environmental impacts through the use of rating systems certified by independent third parties. Green building certification systems address multiple environmental impacts and measure outcomes across all asset lifecycle phases. Using bonds for such investments is not new but in an effort to improve transparency and increase opportunities both for issuers and investors it can take a more active role in combating climate change. The goal of this paper is to describe how property developer can use Green Bond as one instrument in sustainable life cycle management and continuous development of properties. The method used is a case study of Finnish property owner company, which commits to invest the funds raised in certified, environmentally responsible and energy-efficient projects. The single case study method employed in this study captured the process of case organization towards Green Bond initiative. More precisely the data was gathered by qualitative document analysis (QDA). The results show that company begin the process with focusing on environmental sustainability especially putting the effort in the first phase to energy efficiency. The Green Bond initiative provided a new avenue towards economic sustainability. Additionally, issues like shared use of facilities was discussed from social sustainability perspective. The results are interesting for property owners who are interested in systematic development towards regenerative built environment.
Energy analysis and energy planning for kindergartens based on data analysis
Authors: Ding Yiyu , Brattebø Helge , Nord Natasa
Published: October 2019

The aim of the study was to utilize different building data for prediction of development in energy use of a typical building type. In this study, energy use and its future development for kindergartens in Trondheim, Norway, were analyzed. The energy use data were retrieved from the energy monitoring platform of Trondheim Municipality. The total area of all the kindergartens was about 76 000 m2, where the area of each kindergarten was ranging from 100 – 4 471 m2. Firstly, typical heat and electricity duration curves per m2of kindergartens in Trondheim within six years were identified. Secondly, the kindergartens were divided into two cohorts based on their connection to district heating (DH). The average total annual energy use was 177 kWh/m2for kindergartens without DH, and 168 kWh/m2for kindergartens connected to DH. The peak load values were similar for both cohorts, about 140 W/m2. Analysis of the duration curves showed a bigger electricity load variation for the kindergartens without DH connection. Within the building cohort with DH, three cases were found depending on the energy share from DH; i.e. DH high share, DH average share, and DH low share. By following different background data for CO2factors of electricity and local DH, the kindergarten with DH high share had almost the lowest annual CO2emission. Contrarily, the annual CO2emission of a kindergarten with lower share of DH, or without DH, usually had a wider range of emissions due to its dependence of the electricity production mix. Finally, a prediction was made by assuming 14.2 % growth rate of kindergartens on the ground of the average six-year total kindergarten area. The result showed that if more than 50-67 % of the new building area would be connected to DH, a smaller increase of CO2emission from the projected area could be achieved, depending on the relevant CO2factors. This proved that buildings with DH were more robust than the one without DH concerning CO2emission. The suggested analysis method and identified duration curves could be used to as a reference example for defining energy profiles of other building types. These profiles are necessary for diversifying and upgrading local energy supply pathways, infrastructure sizing, and improving urban energy planning.
Future energy pathways for a university campus considering possibilities for energy efficiency improvements
Authors: Nord Natasa , Sandberg Nina Holck , Ngo Huy , Nesgård Eirik , Woszczek Aleksandra , Tereshchenko Tymofii , Næss Jan Sandstad , Brattebø Helge
Published: October 2019

The study aimed to show in a systematic way possible energy efficiency measures that would decrease the total energy use at the university campus in Trondheim, Norway. The entire study was developed in close collaboration with the NTNU Property and Technical Management divisions, meaning that suggested energy efficiency scenarios and other assumptions were highly relevant. Currently, the campus floor area is about 300 000 m2 and consists of buildings combining offices, lecturing halls, study halls, and laboratories. The campus building stock has been built from 1910 to 2002. To perform this study, building performance simulation and the dynamic segmented modeling were combined. A dynamic neighborhood building stock model was utilized to aggregate the outputs from the building simulation and evaluate global effects of energy efficiency measures. Reference building models for each university cohort were developed based on the methodology for defining the reference buildings. The results of the single reference building analyses showed that a decrease of up to 50% in heating energy use might be achieved by increasing efficiency of the ventilation system and by decreasing the temperature of the heating system. The results showed that in spite of building stock growth, the estimated energy use would decrease from 2017 to 2050 by 10% for the standard renovation, and by 26% for the combination of ambitious renovation and technical improvements.
OmrådeLCA, assessment of area development: Case study of the Zero-Emission Neighbourhood Ydalir
Authors: Yttersian V L , Fuglseth M , Lausselet C , Brattebø H
Published: October 2019

The built environment is a major contributor to global greenhouse gas (GHG) emissions. There is a growing need to quantifying GHG emissions, and LCA tools can be used to help address them and find the key contributors. In order to compare different solutions of development of the built environment in the early stage planning process, the OmrådeLCA tool has been developed. OmrådeLCA has the unique advantage, compared to other similar tools, of using the system expansion approach, which allows for comparing different scenarios based on the same functional unit. We applied OmrådeLCA on Ydalir (Norway), a zero emission neighbourhood in an early stage planning process. The results show how significant the share of emissions from transportation are, contributing to more than 60 % to the total GHG emissions. Sensitivity analysis shows that choices made, and data used in modelling transportation significantly impact resulting GHG emissions. Thus, conducting a thorough analysis of factors affecting transportation is important for obtaining representative results when using OmrådeLCA. The results from the assessment of Ydalir with OmrådeLCA have been compared with results from the same case assessed with a tool developed by NTNU. The comparison shows relatively small differences in calculated results. This small degree of variation between the two tools in calculated results, demonstrates that OmrådeLCA can provide good estimates even at an early stage. This gives the tool great utility value because it is in the early stages of a project major actions can be performed and decisions made that will affect the emissions the most.
Review of HVAC strategies for energy renovation of detached houses towards nZEB in cold climates
Authors: Heide V , Georges L , Lien A G , Mathisen H M
Published: October 2019

This paper provides a review of heat and ventilation measures that can be applied to ambitious energy renovation of detached houses in Nordic countries. In this review, requirements for solutions are defined. Key technologies are described and analysed in the context of renovation. The review focuses on strategies that are simple, cost-effective and robust, and can be transposed to the Norwegian context. The review revealed that a wider range of concepts and strategies than commonly used in Norway seem to be relevant. No solution or system appears to be an obvious and universal choice. A number of very different system solutions, with their pros and cons, are relevant, depending on the individual house and situation. Some combined heat and ventilation systems include hydronic space heating. This is however not common in Norwegian houses, and installing this is a major cost and intervention. Wood stoves, on the other hand, are regular, and can be used for peak heating. These factors seem to be crucial for the choice of system. Improved airtightness after renovation makes systematic ventilation measures necessary. Assumptions for occupant preferences and behaviour also seem to be important for choice of system. There are also differences in the commonly used HVAC concepts and strategies for renovation between the Nordic countries. These differences do not seem to be explained by climate only, and differences in building code may be part of the reason. A number of demonstration projects on ambitious energy upgrading are completed, but few of them have been systematically monitored and evaluated.
Assessing cities: Applying GIS-based methods for mapping cross-scale spatial indicators
Authors: Rokseth L S , Manum B , Nordström T
Published: October 2019

In recent years, several systems and tools to assess energy consumption and carbon emissions at scales beyond that of merely buildings, such as LEED, CASBEE and BREEAM communities have been development. However, reviews reveal a lack of robustness in these methods both in terms of an unstructured mix of qualitative and quantitative criteria and lack of focus on urban form parameters found to influence energy consumption and carbon emissions. A promising quantitative assessment system including various urban form indicators is developed by the Urban Morphology Institute (UMI) in Paris. Within the research centre on zero emission neighbourhoods in smart cities (ZEN), a GIS-based method is applied to analyze conditions of urban form known to contribute to carbon emissions. In this paper we demonstrate how a selection of the UMI indicators describing proximity can be further specified applying GIS-based methods. The potential of applicability of urban assessment system in planning as well as design processes will increase when linked to tools that are already implemented, and map visualizations as well as data provided by these methods are highly applicable in planning and urban design. As further research, methods described in recent research within ZEN and specified measures for calculating UMI indicators, will be tested in analyses of urban development areas in Norway.
Energy efficiency of strategies to enable temperature zoning during winter in highly-insulated residential buildings equipped with balanced mechanical ventilation
Authors: Georges L. , Selvnes E. , Heide V. , Mathisen H.M.
Published: October 2019

To reduce the space-heating needs, balanced mechanical ventilation equipped with a heat recovery is frequently implemented in highly-insulated residential buildings. This standard ventilation strategy tends to homogenize temperature inside the building, in other words, to reduce temperature zoning. In some countries, such as Norway, many users would like colder bedrooms. It has been proved that a significant part of the occupants in Norwegian passive houses opens bedroom windows during several hours every night during winter. Dynamic simulations have shown that it strongly increases the space-heating needs and that control only is unable to create temperature zoning in an energy-efficient way. The building concept should be changed. In the present contribution, the physical processes during temperature zoning are further explained. Detailed dynamic simulations of a detached single-family house are performed using the simulation software IDA ICE for different insulation levels, construction modes (which also influence the thermal insulation in partition walls) and control strategies. Alternative mechanical ventilation strategies are compared. They manage to reduce the influence of mechanical ventilation on the increased space-heating needs due to window opening but they cannot improve the large contribution of heat conduction through partition walls between heated areas and unheated bedrooms. Among the investigated ventilation strategies, decentralized ventilation has intrinsically the best performance.
Overheating and daylighting evaluation for free-running classroom designs
Authors: Kiil M , Simson R , de Luca F , Thalfeldt M , Kurnitski J
Published: October 2019

Learning performance is strongly related to thermal comfort and lighting conditions of classrooms. Poor facade design can result in high indoor temperatures or insufficient access to natural light. To maintain the required temperatures and illuminance levels in such rooms may require intensive use of artificial lighting and active cooling systems, which are energy-intensive, costly to install, operate and maintain. The purpose of this study was to determine essential parameters and facade design options that ensure overheating prevention and fulfil daylight requirements in classrooms without mechanical cooling. The present study is based on simulations of a parametric room model with variable dimensions and orientations. Facade glazing solutions with optimal combination of solar factor and visible light transmittance were used to minimize overheating risk and maximize natural lighting impact. For east, south and west oriented facades, the effect of horizontal shading was also analysed. Overheating assessment through indoor temperature simulations was conducted with dynamic simulation software IDA ICE, daylighting was simulated with DIVA4 coupled with Grasshopper software. Results show that classrooms without mechanical cooling require in depth analysis to determine satisfying solutions for both overheating and daylighting criteria. The results of this paper can be used for early stage facade design guide for school buildings or similar use free-running buildings.
Study of Voltage Stability Due to Shading Effects on Photovoltaic Penetration in PKMT Distribution System
Authors: Nabila N , Bangun G M , Budiansyah M A , Alvianingsih G , Utomo A R
Published: October 2019

PV output power is firmly influenced by temperature and solar irradiation that fall on the surface of the PV modules. Shading which cross-wising the surface of PV modules is major factor that prevails the degradation of its performance. The shading in PV arrays is caused by the presence of cloud, dust, fog, trees, the shadow near buildings, and so on. As the result of the shading effect, the voltage and current outputs fluctuate which would in turn reducing the efficiency of the PV output. The voltage and current of PV solar cells will drop from partial shading effect experiment which consists of 20%, 40%, 60%, 80%, and 100% shading area. This paper shows the effect of PV system over the voltage stability by variating the shading conditions using simulation by ETAP software 12.6.0.
Characteristics of disturbance in frequency 9 -150 kHz of Rasuna Said gas station’s solar panel system
Authors: Hood M L , Sudiarto B
Published: October 2019

Dependence on the usage of fossil fuel energy sources as a source of electrical energy to overcome the increase in electrical energy needs. The high demand for electricity encourages the development of the use of non-fossil energy sources. One of the new and renewable energy sources producing electricity is solar energy from the sun. Solar panels produce DC electricity which can be converted into AC electricity using an inverter so that it can be connected to an AC load. The switching process and the use of power electronic components in the inverter can generate electrical wave distortion such as disturbance with 9 – 150 kHz frequency in the solar panel system. In this study, the characteristics of the disturbance frequency 9-150 kHz reviewed and their effects on solar irradiation. Furthermore, it shows that the solar panels system-generated disturbance and increased by 1.5 – 12.6% per 100 W/m2
An Improved P&O Algorithm for Single-Stage Grid-Connected Photovoltaic System under Rapidly Changing Environment Conditions
Authors: Kusuma A A B , Hakim M D E , Alvianingsih G , Aryani D R , Utomo A R
Published: October 2019

In producing its power, Photovoltaic (PV) performance is influenced by environmental factors, such as solar irradiance and temperature. System stability is needed to maintain safe operation of the system. This paper presents a Maximum Power Point Tracking (MPPT) control model of PV array to improve system reliability and the performance of MPPT. The main parameters in Matlab/Simulink simulation that become the highlight influences are the changes in solar irradiance from 500W/m2 to 1000W/m2 and ambient temperatures from 25°C to 50°C. With the control algorithm that has been made in the Perturb and Observe (P&O) method, it obtains the optimal voltage control point in each PV conditions in a power system. System simulation shows that the voltage stability was maintained above 510 Volt in various conditions of solar irradiance and temperature. The results of the control scheme show the stability of the system and the optimal performance of PV.
Purification of silica from tin tailings through solid-state method
Authors: Evi J , Tiandho Y , Rafsanjani R A , Afriani F
Published: October 2019

Indonesia is one of the largest tin producers in the world. The by-products of processing tin ore in the form of tailings are not used properly. Based on several studies, tin tailings have high levels of silica. In this paper, a silica purification study from tin tailings is proposed using a solid-state method at different pH. The purity of silica in this paper is determined by XRF and XRD analysis. This research is expected to increase the economic value of tin tailings, which can be utilized in various applications.