• Journal of the Korea Society of Computer and Information
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• v.14 no.10
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• pp.55-61
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• 2009

This paper describes a point of production(POP) system which collects and manages real-time shop floor machining information in a wafer dicing process. The system are composed of POP terminal, line controller and network. In the configuration of the system, LAN and RS485 network are used for connection with the upper management system and down stratum respectively. As a bridge between POP terminal and server, a line controller is used. The real-time information which is the base of production management are collected from information resources such as machine, product and worker. The collected information are used for the calculation of optimal cutting condition. The collection of the information includes cutting speed, spout of pure water, accumulated count of cut in process for blade and wafer defect. In order to manage machining information in wafer dicing process, production planning information is delivered to the shop floor, and production result information is collected from the shop floor, delivered to the server and used for managing production plan. From the result of the system application, production progress status, work and non-working hour analysis for each machine, and wafer defect analysis are available, and they are used for quality and productivity improvements in wafer dicing process. A case study is implemented to evaluate the performance of the system.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.174-182
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• 2004

Hygienic standards for pizza specialty restaurant located in Seoul during summer, 2000 were established based on HACCP concept by measuring temperature, time, pH, $A_{w}$ and microbiological assessments of pizza, and evaluation of hygienic conditions of kitchens and workers. Kitchen and worker conditions were average 1.2 and 1.0 (3 point Sly's scale), respectively, Microbial contaminations occurred at $5-60^{\circ}C$, pH above 5.0, and $A_{w}$ (0.93-0.98). Microbial assessments for pizza processing revealed $1.5{\times}10^{2}-3.9{\times}10^{8}\;CFU/g$ of TPC and $0.5{\times}10^{1}-1.6{\times}10^{7}\;CFU/g$ of coliforms, exceeding standards ($TPC\;10^{6}\;CFU/g\;and\;coliform\;10^{3}\;CFU/g$) established by Solberg et al., although significantly decreased after baking. S. aureus was not discovered, but Salmonella was found in onions. Tools and containers such as pizza cutting knife, topping container, serving bowl, pizza plate, working board, and dough kneading board contained $6.2{\times}10^{2}-1.1{\times}10^{9}\;CFU/g$ of TPC, $2.0{\times}10^{1}-6.2{\times}10^{3}\;CFU/g$ of coliforms. Workers' hands contained $3.1{\times}10^{4}\;CFU/g$ of TPC and S. aureus as compared to safety standards of Harrigan and McCance (500 and 10 CFU/g of TPC and coliforms per $100cm^{2}$). CCPs (critical control points) were determined as receiving, topping, and baking according to CCP decision tree analysis. Results suggest purchase of quality materials, careful monitoring of time and temperature, hygienic use of tools and utensils, and sanitary practicer by workers are recommended as control points for safe pizza production.

• Journal of the Society of Naval Architects of Korea
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• v.55 no.2
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• pp.136-143
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• 2018

3-D templates are produced to evaluate completeness of the shell plates during the forming process, which is an essential step for the ship production. They are mostly produced in advance during the detail/production design stage, but occasionally they are requested by the shell plate forming department, because it is impossible to predict accurately the necessities of them at the design stage. This results in a huge loss of man-hour and a bottleneck. In order to resolve this issue while reducing the dependence on other department, the process of manufacturing the 3-D templates needs to be automated. Therefore, this study proposes an automatic system that calculates the manufacturing information of the 3-D templates with only geometric information of the shell plates. The system considers the thickness and the cutting method of the parts of the 3-D templates and some options are provided to reflect the intention of the worker.

• Tribology and Lubricants
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• v.30 no.6
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• pp.343-349
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• 2014

Currently, in order to resist the scratching of the fuel rod surface while fabricating the fuel assembly of the light-water nuclear reactor, we use a solution of nitrocellulose, an explosive material, as a dry lubricant along with its solvent. However, the demand for developing safe and harmless aqueous alternative materials for environment-conservation and field-worker safety has increased. In this study, we demonstrate the preparation of a novel aqueous resin composite using a formulation of aqueous polymeric resin, alcoholic solvent, and water. Subsequently, we characterize this composite on the basis of hardness, adhesive property, and water solubility using plates similar to the fuel rod material. The insertion test of a fuel rod coated with the YS-3 composite shows load values of $18.8-20.5kg/cm^2$, which is comparable with $18.8-20.5kg/cm^2$ of the nitrocellulose coating agent. In addition, the depth and width of longitudinal scratches caused by the YS-3 composite test are 50% higher than those of the standard. We can develop a harmless and safe aqueous dry lubricant to replace the existing NC products through field testing of 264 pieces of fuel rods, after producing 350 kg of the YS-3 prototype. The scratch test for the rod surface showed that weight of chip of YS-3 prototype was smaller than that of NC before and after solvent treatment, indicating the properties of YS-3 prototype was comparable to the counterpart.

• Korean journal of applied entomology
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• v.47 no.1
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• pp.95-100
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• 2008

We compared colony development and survival rate after artificial hibernation between the bumblebees, Bombus terrestris, produced from domestic and foreign companies. The number of worker and queen produced from foundation colony of three domestic and one foreign companies was 232.4-270.8 and 62.0-181.8, respectively, but there was no statistical difference. In colony development of B. terrestris queens which were terminated diapause by $CO_2$ narcosis at different companies, oviposition rate, colony foundation and progeny-queen production of bumblebees produced from domestic companies were superior to those from foreign company. But foreign company in the number of worker and queen was superior to domestic companies. On the other hand, survival rate and colony development of B. terrestris queens, which were terminated diapause by artificial hibernation at three domestic and two foreign companies, were no significant differences. These results indicate that oviposition, colony foundation, progeny-queen production, and survival rate after artificial hibernation showed no differences between the bumblebees produced from domestic and foreign companies.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.93-108
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• 2023

In manufacturing productivity analysis, understanding the intricate interplay among factors like facility performance, layout design, and workforce allocation within the production line is imperative. This paper introduces a simulation-based methodology tailored to food manufacturing, progressively expanding scenarios to analyze production enhancement. The target system is a food processing plant, encompassing production processes, including warehousing, processing, subdivision, packaging, inspection, loading, and storage. First, we analyze the target system and design a simulation model according to the actual layout arrangement of equipment and workers. Then, we validate the developed model reflecting the real data obtained from the target system, such as the workers' working time and the equipment's processing time. The proposed model aims to identify optimal factor values for productivity gains through incremental scenario comparisons. To this end, three stages of simulation experiments were conducted by extending the equipment and worker models of the subdivision and packaging processes. The simulation experiments have shown that productivity depends on the placement of skilled workers and the performance of the packaging machine. The proposed method in this study will offer combinations of factors for the specific production requirements and support optimal decision-making in the real-world field.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.5
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• pp.275-280
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• 2002

In order to control glucose concentration during fed-batch culture for antibiotic production, we applied so called “software sensor” which estimates unmeasured variable of interest from measured process variables using software. All data for analysis were collected from industrial scale cultures in a pharmaceutical company. First, we constructed an estimation model for glucose feed rate to keep glucose concentration at target value. In actual fed-batch culture, glucose concentration was kept at relatively high and measured once a day, and the glucose feed rate until the next measurement time was determined by an expert worker based on the actual consumption rate. Fuzzy neural network (FNN) was applied to construct the estimation model. From the simulation results using this model, the average error for glucose concentration was 0.88 g/L. The FNN model was also applied for a special culture to keep glucose concentration at low level. Selecting the optimal input variables, it was possible to simulate the culture with a low glucose concentration from the data sets of relatively high glucose concentration. Next, a simulation model to estimate time course of glucose concentration during one day was constructed using the on-line measurable process variables, since glucose concentration was only measured off-line once a day. Here, the recursive fuzzy neural network (RFNN) was applied for the simulation model. As the result of the simulation, average error of RFNN model was 0.91 g/L and this model was found to be useful to supervise the fed-batch culture.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.23
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• pp.341-372
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• 2004

Since China was admitted to the World Trade Organization (WTO) on December 11, 2001, China has sped up its active participation in the competition of the world economy by lifting its trade and investment restrictions and limits. Its trading system is getting more and more free and its huge market with a population of 1.3 billion has been getting more and more open. With Chinas WTO accession, China has been honoring its commitments to its WTO members by complying with international business practices and WTO rules. For example, it will cut down its import tariffs for automobiles from the present 80% to 25% by 2006. Its financial sector and service industries are open to foreign investors now. As Chinas biggest business partner, Japan has benefited tremendously from Chinas open policies and deepening economic reform. In order to reduce the costs of production, a large number of enterprises from Japan have set up production bases in China since a Chinese workers wages accounts for only one tenth of those of a Japanese worker on the average. Japan has become one of Chinas biggest investors on a par with the United States of America (USA). How are the Japanese enterprises in Japan and in China adjusting themselves to the rapid changes of the Chinese market? What characteristics do the Japanese enterprises in China have? What effects has Chinas WTO accession had on those Japanese enterprises that have invested in China? This paper finds answers to the above questions. It at first reviews the Sino-Japanese economic and trade relations since 1980s, then analyses the situation and characteristics of Japanese-invested enterprises in China, and explores their problems in China. Finally it puts forward some suggestions for the Japanese enterprises in China.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.5
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• pp.353-359
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• 2017

The classical computer numerical control (CNC) machine is widely used for mold making in various industries. However, while improving the process, it has a negative effect on production quality and worker safety. As a result, the complaints of workers have increased and production quality has decreased. Therefore, we found optimizing cutting conditions to mold industrials for cutting conditions commonly used. However, the problem is the insert tool geometric modeling. In this study, the modeling of an insert tool was performed using the Solidworks program. The insert tool model was imported into the analysis application AdvantEdge, which predicted cutting forces, tool stress, and temperature.

• Food Science of Animal Resources
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• v.40 no.3
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• pp.401-414
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• 2020

The emergence and persistence of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) in livestock animals have been reported as a potential risk factor for transmission to humans. In this study, we investigated the nationwide prevalence and characteristics of MRSA and MSSA in the Korean beef production system, including retail markets, slaughterhouses, and cattle farms. From a total of 1,285 samples, only 5 MRSA strains were isolated: from a farmer (1 ST72 MRSA), a carcass sample from a slaughterhouse (1 ST72 MRSA), and beef cattle (3 ST5 MRSA). In addition, 11 MSSA strains were isolated from beef cattle (n=3), humans (1 farmer, 1 slaughterhouse worker, and 4 retail market workers), and carcass samples (n=1) and slaughterhouse environment (n=1). Although the prevalence of MRSA and MSSA in beef cattle was much lower than that reported in pigs, 5/5 MRSA and 2/11 MSSA strains displayed multiple drug resistance (MDR) phenotypes. Unlike the swine-associated MRSA, no correlation was found between tetracycline/zinc resistance and MDR phenotype. However, MRSA strains had an identical set of staphylococcal enterotoxins and exhibited enhanced levels of resistance to antimicrobial peptides (PMAP-36 and LL-37) compared to the MSSA strains. In conclusion, continued and systemic surveillance of livestock, meat products, and humans in close contact with livestock/meat products is necessary to prevent the transmission of MRSA and MSSA to humans.