Judul: Noise Analysis of Biodiesel Plant P3 Machinery Production to The Operator Performance at PT SMART Tbk., Marunda, Jawa Barat
Abstrak: Noise is one of the essential aspects in ergonomics. This study aims to analyze the distribution pattern of noise in the biodiesel production factory room, evaluate the magnitude of noise received by the hearing sense of the operators of the biodiesel Plant P3 production machine, and determine the appropriate Noise Risk Assessment based on the analysis. PT SMART Tbk. has a biodiesel Plant P3 factory that operates 24 hours, and the use of various machines results in a significant level of noise. The measurement results indicate that the noise levels on floors 1 through 4 are below the threshold value. However, the noise level on the 5th floor exceeds 85 dB, which means that workers can work without maximum protective equipment for only 57 - 64.2 minutes. Therefore, it is necessary to control the noise by reducing the noise on the 5th floor to avoid compromising the health and comfort of the workers. The use of personal protective equipment is also essential to mitigate the negative impact of noise exposure on the workers in the factory environment.
Keyword: Ergonomics, Noise, Biodiesel Production, Threshold Limit Value, Noise Risk Assessment

Judul: Analysis of noise on black tea processing in milling, drying, and sorting room of PTPN VIII Gunung Mas Plantation, Cisarua, West Java
Abstrak: Tea plant is a green leafy plants commonly cultivated in high mountain regions. Black tea was made through fermentation, and furthermore black tea was divided into two types, they are orthodox tea and CTC tea (Crushing, Tearing, and Curling). The processing of CTC tea at PTPN VIII Gunung Mas Plantation include acceptance of raw material, disclosure of tea leaves, withering, milling and fermentation, drying, sorting and packaging. PTPN VIII Gunung Mas Plantation running the production activity by using the machines in large scale. The use of machinery on a large scale resulted in positive impact and negative impact for worker and company. One of the negative impacts suffered by workers is noise impact. Noise can be defined as undesirable sound, annoying sound, or irritating sound that in the long run will be able to disrupt the comfort when working. Noise that exceeds the threshold value will cause a reduction in auditory function, and if it goes on will cause deafness in factory workers. This can lead to decrease in concentration of work. The purpose of measuring noise in the factory is to analyze the areas that produce high noise so that the factory worker can work in the factory according to a predetermined safe time, this is to reduce the negative effects of noise. High frequency noise can be found in milling room, drying room and sorting room. The pattern of noise spread on every shift are not equal, it is because the number of machines that operating in shift 1 and shift 2 was different, so that the noise value in shift 1 was higher than shift 2. The noise value in milling room, drying room and sorting room exceeds the threshold value. Therefore, the safe time for being in that rooms were average below 8 working hours/day. To prevent damage to auditory, worker advised to use ear protection device to protect their auditory during work.
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Judul: Pelabelan Super Vertex Magic
Abstrak: Super vertex magic labeling is labeling on graph with is a set of edges mapped into and is a set of vertices mapped into . It has a vertex magic labeling in which and represents the size and order of the graph respectively. This manuscript proves that paths, cyclics, and disjoint union of cyclics have a super vertex magic labeling. There are four theorems to be discussed. The first theorem proves that path is super vertex magic if and only if is odd and . The second theorem proves that cyclic is super vertex magic if and only if is odd. The third theorem proves that bijection function from an edge set onto of graph can be extended to a super vertex magic labeling if and only if the set amount of edge label that incidents with a vertex in the graph, consists of sequential integers as many as vertices in the graph. The fourth theorem proves that disjoint union of the cyclics consists of cyclics with each cyclic has vertices is super vertex magic if and only if and are odd.
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