###### Abstract  
Currently, the _User-PC computingsystem_ (_UPC_) has been studied as a low-cost and high-performance distributed computing platform. It uses idling resources of personal computers (PCs) in a group. The job-worker assignment for minimizing _makespan_ is critical to determine the performance of the UPC system. Some applications need to execute a lot of _uniform jobs_ that use the identical program but with slightly different data, where they take the similar CPU time on a PC. Then, the total CPU time of a worker is almost linear to the number of assigned jobs. In this paper, we propose a _static assignment algorithm_ of _uniform jobs_ to workers in the UPC system, using _simultaneous linear equations_ to find the _lower bound_ on _makespan_, where every worker requires the same CPU time to complete the assigned jobs. For the evaluations of the proposal, we consider the uniform jobs in three applications. In _OpenPose_, the CNN-based _keypoint_ estimation program runs with various images of human bodies. In _OpenFOAM_, the physics simulation program runs with various parameter sets. In _code testing_, two open-source programs run with various source codes from students for the _Android programming learning assistance system_ (_APLAS_). Using the proposal, we assigned the jobs to six workers in the testbed UPC system and measured the CPU time. The results show that _makespan_ was reduced by 10% on average, which confirms the effectiveness of the proposal. U  
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These jobs have the common feature of a similar CPU time when they run on a specific PC. The _uniform jobs_ often need a long CPU time. For example, in physics or network simulations, it can take several days to run one job. Nevertheless, it will be necessary to find the best result of all the input data by repeating them to slightly change some parameter values for the program and running them. This work can be common in research activities using computer simulations. In this paper, we propose a _static assignment algorithm_ of _uniform jobs_ to workers in the UPC system, using _simultaneous linear equations_ to find the _lower bound_ on _makespan_, where every worker requires the same CPU time to complete the assigned jobs. The _simultaneous linear equations_ describe the equality of the estimated CPU time among the workers, and the equality of the total number of assigned jobs to workers with the number of given jobs. The estimated CPU time considers simultaneous executions of multiple jobs on one worker by using its multiple cores. Since solutions of _simultaneous linear equations_ become real numbers in general, the integer number of jobs assigned to each worker is introduced to them in a greedy way. For evaluations of the proposal, we consider _uniform jobs_ in the three applications for the UPC system, namely, _OpenPose_[3], _OpenFOAM_[4], and _code testing_[5; 6]. For _OpenPose_, the CNN-based program runs with 41 images of human bodies. For _OpenFOAM_, the physics simulation program runs with 32 parameter sets. For _unit testing_, the open-source programs run with 578 source codes that were submitted from students to the server in the _Android programming learning assistance system (APLAS)_. These jobs were applied to the proposed algorithm and were assigned to six workers in the testbed UPC system by following the results. Then, the CPU time was measured by running them. For comparisons, two simple algorithms were also implemented where the jobs were applied, and the CPU time was measured. The evaluation results show that the difference between the longest CPU time and the shortest one among the six workers became 92 s, and _makespan_ of the UPC system was reduced by 10% on average from the results by comparative algorithms. Thus, the effectiveness of the proposal was confirmed. The proposed algorithm limits the application to the jobs where the CPU time is nearly equal to a worker.