• Nuclear Engineering and Technology
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• v.56 no.5
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• pp.1781-1795
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• 2024

This study investigated the levels of radioactivity in soil surrounding a phosphate fertilizer factory in Egypt, aiming to assess potential risks to the population exposed to radiation. Concentrations of ²³⁸U, ²²⁶Ra, ²³²Th, and ⁴⁰K were measured in soil samples collected from two subsites: one near the factory (subsite 1) and another further away (subsite 2). Two different systems were used for measuring radioactivity, a high-purity gamma ray spectroscopy system with an HPGe detector for gamma-emitting isotopes and a CR-39 solid nuclear track detector for alpha-emitting radon gas. Subsite 1, located close to the factory, displayed significantly elevated levels of ²²⁶Ra compared to global background levels (514 and 456 Bq/kg vs. 35 Bq/kg). Additionally, the concentrations of ²³⁸U (241.06 Bq/kg vs. global average 35 Bq/kg), ²³²Th (16.15 Bq/kg vs. global average 30 Bq/kg), and ⁴⁰K (146.36 Bq/kg vs. global average 400 Bq/kg) were all above global averages. Furthermore, a high concentration of radon gas (337.06 μSv/y) was measured at subsite 1. The strong positive correlation observed between ²²⁶Ra and ²³⁸U (0.96256) provides further evidence of potentially elevated radioactivity levels near the factory. In contrast, subsite 2, situated farther from the factory, exhibited natural radioactive background levels within international limits. Quantitative analysis revealed that gamma ray absorbed doses for ²²⁶Ra and ²³²Th exceeded global averages in some samples. Specifically, ²²⁶Ra doses ranged from 7.8 to 46.26 ppm (exceeding the 20 ppm global average in some cases), and ²³²Th doses ranged from 1.98 to 9.14 ppm (exceeding the 10 ppm global average in some cases). The concentration of ⁴⁰K, however, remained within the global range (0.07%-0.69 %). The observed imbalances in the ratios of Th/U (0.17-0.24 Bq/kg and 0.73-0.24 ppm) and U/Ra (0.81-0.73 Bq/kg and 0.73-0.17 ppm), both of which are significantly lower than their respective global averages of 4 and 2.4, point towards the presence of fertilizer-derived contamination. This conclusion is further supported by the high phosphate concentrations detected in the samples. Overall, this study suggests that radioactive contamination near the phosphate fertilizer factory significantly exceeds global background levels and international limits in some cases. This raises concerns about potential risks posed to surrounding agricultural land and crops.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.10
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• pp.992-1000
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• 1991

At present, using different method, in the view of point of that factory to the rising of the productivity, they try to rise productivity by factory automation. First, it is the automation of each unit process. In out country, in the case of a few developed factory. they are realized by line automation. The majority factories are established by automation device of unit process. But, as the established devices, it must be connect between unit processes or mutual assistance and offical automation in order to raise up productivity highly. In this paper, process inspection control system is installed by each unit process automation and connect main computer with them. So, we try to rise high productivity using stochastic process and supervision function.

• Journal of Korean Institute of Industrial Engineers
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• v.41 no.5
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• pp.470-480
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• 2015

There are many challenges in manufacturing system for new factory construction. Although factories produce same product, the layout of each factory may be different. The body shop in an automotive factory is a typical flow line with assembly, but the layout concept of the line varies among factories. In this paper, two types of layouts in the body shops of automotive factories, one for layered build and the other for modular build, are compared using simulation study. The simulation experiments indicate that the modular build layout is better than the layered build layout with respect to production rate. The effects of various failure distributions on the throughputs are also investigated, and some insights are suggested regarding the layout concept.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.411-414
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• 2015

The purpose of this study is to conduct a comparative analysis between Korea and the United States of the supply process of unit modular housing at both the factory production phase and the transportation and lifting phase, as part of an attempt to invigorate the unit modular housing market in Korea. Unlike the practice in the United States, one of Korea's unique characteristics is that the floor is constructed with reinforced concrete and hot water heating system. To do this, the wet method in Korea is used that includes concrete placement, curing and constructing hot water floor heating system at the factory production phase, which results in a longer production time and also requires the lifting of heavier loads. In the United States, interior and exterior finishing works of modular housing are performed by different companies, and the distance between the unit module factory and the construction site is quite far. This kind of dualized production structure may cause confusion when it comes to schedule management, procurement management, and stock management. Moreover, problems caused by external environmental factors such as wind and rainfall were reported in the course of long-distance transportation. The results of this case comparison are expected to provide fundamental data that will reduce the amount of trial and error in the unit module production, transportation and lifting work in Korea, which has a comparatively small number of unit modular housing cases.

• Journal of Practical Engineering Education
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• v.15 no.2
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• pp.429-438
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• 2023

Recently, demand for smart factories is increasing in response to the era of the 4th industrial revolution. Smart factory is basically a manufacturing industry based on massive data, which requires IT services for processing a lot of data, which is accelerating the construction of data centers. Data center computing equipment requires a different approach from the cooling technology of general facilities in terms of heat load and usage time. This study investigates the factors to be reviewed in the recent data center cooling system design and technological change trends, compares and reviews various technological methods for facility configuration of case companies, derives the design decision process, and draws up a conceptual design corresponding to the conclusion.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.333-342
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• 2010

For the energy-saving production of fresh vegetables in poor environment such as the Antarctic, a container-type plant factory was designed and developed. To maximize space usage of the 20 feet container ($L5.9m{\times}W2.4m{\times}H2.4m$), a three-level hydroponic cultivation system was installed and the nutrient solution was supplied by bottom watering. Using this system, 3 lettuce cultivars were grown under different the light source (light intensity). After 2 weeks from the transplanting, fluorescent lamp ($145\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) showed the best fresh weight of top part and leaf area. However, After 4 weeks, fluorescent lamp plus metal halide lamp ($150\;{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) led to the optimum growth of the each lettuce cultivar. The cultivar, 'Cheongchima', showed the best fresh weight of top part and leaf area, followed by 'Jeokchukmyeon' and 'Lollo rosa'. The chlorophyll concentrations (SPAD) showed no significant difference among the sources of lights. However, 'Cheongchima' showed relatively high chlorophyll concentration. With the above results, we found that the growth of lettuce is depend on light intensity and even at same intensity, the growth is different among the cultivars. Therefore, the selection of optimum cultivar should be considered in the plant factory system that has only weak light density.

• ALGAE
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• v.33 no.4
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• pp.319-327
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• 2018

Ettlia sp. YC001, a highly settleable and productive microalga, was shown to be effective in removing nutrients and capturing suspended solids from eutrophic pond water. The optimum conditions for the Ettlia sp. YC001 cultivation were investigated using water from a landscape pond. The pond water was supplemented with different N : P ratios by weight, and the biomass production and nutrient removal compared in batch cultures. The maximum removal rate of N and P was with an N : P ratio of 16 : 1. Plus, the turbidity dropped to near zero within 4 days. Meanwhile, chemostat cultivation showed that the biomass productivity and nutrient removal rate increased when increasing the dilution rate, where a dilution rate of $0.9d^{-1}$ showed the highest N and P removal rate at $32.4mg\;L^{-1}\;d^{-1}$ and $1.83mg\;L^{-1}\;d^{-1}$, respectively, and highest biomass and lipid productivity at $0.432g\;L^{-1}\;d^{-1}$ and $67.8mg\;L^{-1}\;d^{-1}$, respectively. The turbidity was also reduced by 98% in the chemostat cultivation. Moreover, auto-flocculation and pH were closely connected to the turbidity removal. As a result, this study identified the optimal N : P ratio for small pond water treatment using an Ettlia sp. YC001, while also establishing the optimal conditions for nutrient removal, turbidity reduction, and biomass production.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7990-8000
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• 2015

Plant factories are plant cultivation systems which produce farm products uniformly under the controlled environmental condition regardless of seasons and places. Thermal flow in the plant factory is an important parameter in cultivating plants. In this research, we study thermal flow characteristics for a hybrid plant factory with multi-layer cultivation shelves using computer simulation techniques. In order to obtain numerical solutions for thermal flow characteristics, a finite volume method was applied. We consider a low-Reynolds-number ${\kappa}-{\epsilon}$ turbulence model, incompressible viscous flows, and pressure boundary conditions for numerical simulation. Commercial software Solid Works Flow Simulation is then used to investigate characteristics of thermal flows in the plant factory applying several different inflow air velocities and arrangements of cultivation shelves. From numerical analysis results, we found that temperatures in cultivation shelves were uniformly distributed for Case 3 when the inflow air velocity was 1.6 m/s by using a blower in the plant factory. However in Case 1 lower temperature distributions were observed in test beds, TB2 and TB3, which indicated that additional temperature control efforts would be required. Average shelf temperature increased by $3^{\circ}C$ using artificial light source (DYLED47) with 50% blue and 50% red LED ratios. Korea Academia-Industrial cooperation Society.

• Physical Therapy Rehabilitation Science
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• v.11 no.4
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• pp.553-564
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• 2022

Objective: The purpose of this studyaimed to investigate the effects of scapular stabilization training using the different exercise prop for impingement syndrome of factory workers. Design: A randomized controlled trial Methods: Twenty shoulder impingement syndrome subjects were randomly divided into two groups of ten subjects each. Inclusion criteria was presence of positive sign in at least two of Neer test, Hawkins test, Yocum test, Jobe test and Speeds test. Andexclusion criteria, those with surgical history of rotator cuff, those with disease in upper limb other than shoulder impingement syndrome, those who took anti-inflammatory drugs over the past 12 months were excluded from the sample. One group was performed scapula stabilization exercise using elastic bands, while dumbbell group performed the exercise using dumbbell. Both groups performed the exercise after applying the general physical therapy. After applying five days a week for a total of six weeks, range of motion of shoulder joint, muscle strength and pain and function level were evaluated. Results: After the intervention, in both groups, all dependent variables at the 6-week post-test significantly improved compared with the pre-test (p<0.05). In addition, elastic band exercise group showed a significant differences in SPADI function score and SPADI total score compared to the dumbbell group(p<0.05). Conclusions: The elastic band training may be effective methodology using low-to-moderate intensity resistance for SPADI scores.

• Tribology and Lubricants
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• v.19 no.1
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• pp.36-42
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• 2003

Nowadays the importance of equipment reliability and efficiency is increasing and the concept of Total Fluid Management is introduced to make production cost down and improve equipment reliability. In this paper, basic survey on the current status of lubricants application and equipment maintenance is made. Lubrication point of the factory was 233 and 60 percent of the point was lubricated by hydraulic oils. Lubricants used at 87 points were different from those of original equipment manufacturers' recommendation. And 40 percent of the points are heavily contaminated. Exchange of oils, use of filter, computerization and so on were recommended. And introduction of Total Fluid Management concept is required.