• Journal of Korean Institute of Industrial Engineers
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• v.26 no.3
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• pp.238-248
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• 2000

Facilities are getting more automated and informative in modern manufacturing systems, especially in semiconductor and LCD plants. These systems keep a great deal of such information on its current and near-future status as the arrival time and job completion time of their parts. This paper presents an efficient policy for AGV and part routing using information on the future status of the system where AGVs are playing a central role for material handling. Efficient control of AGVs is very important because AGV systems often become the bottleneck and limit the total production capacity of a very expensive plant. The cell controller records the future events chronologically in Next Event Schedule, and uses this list to determine to which place the AGVs and parts to be sent.

• Journal of the Korea Safety Management & Science
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• v.25 no.2
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• pp.1-8
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• 2023

This paper is proposing a novel machine scheduling model for the unrelated parallel machine scheduling problem without setup times to minimize the total completion time, also known as "makespan". This problem is a NP-complete problem, and to date, most approaches for real-life situations are based on the operator's experience or simple heuristics. The new model based on the Memetic Algorithm, which was proposed by P. Moscato in 1989, is a hybrid algorithm that includes genetic algorithm and local search optimization. The new model is tested on randomly generated datasets, and is compared to optimal solution, and four scheduling models; three rule-based heuristic algorithms, and a genetic algorithm based scheduling model from literature; the test results show that the new model performed better than scheduling models from literature.

• The Korean Journal of Pain
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• v.14 no.2
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• pp.181-185
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• 2001

Background: Bradycardia frequently occurs in intravenous anesthesia with propofol. Additionally, the thoracic sympathetic nerves influence the heart so that the heart rate (HR) and blood pressure are expected to decrease due to this procedure. Therefore, we measured changes in HR, mean arterial pressure (MAP) and both thumb temperatures before and after thoracic sympathicotomy under total intravenous anesthesia with propofol. Methods: The subjects included 21 outpatients of ASA class I who received thoracoscopic thoracic sympathicotomy under total intravenous anesthesia. Anesthesia was induced with propofol (2 mg/kg) and vecuronium (0.1 mg/kg) and maintained with propofol-fentanyl-oxygen (100%). The surgical procedure was performed at the T3 level in the order of left sympathicotomy (LST) and right sympathicotomy (RST). Measurements of HR, MAP and both thumb temperatures were taken before induction of anesthesia, before and after LST and RST, and 1 hour after the completion of anesthesia. Additionally, the time to the beginning of a rise in temperature in both thumbs after sympathicotomy was recorded. Results: HR did not show any significant difference before or after sympathicotomy, however it decreased at 1 hour after the completion of anesthesia. MAP decreased after LST and decreased further after RST. Left thumb temperature began to increase at $45.8{\pm}10.7$ seconds after LST. Right thumb temperature initially decreased after LST and increased from $45.2{\pm}11.8$ seconds after RST. Subsequently, both increased temperatures were maintained at 1 hour after the completion of anesthesia. Conclusions: Although HR and MAP decreased, there were no severe hemodynamic changes. An increase in the thumb temperature was confirmed within 1 minute after sympathicotomy on the same side.

• Korean Journal of Microbiology
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• v.11 no.4
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• pp.167-174
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• 1973

This study included two parts of investigation, the microfloral changes during the brewing process with the changes of pH, total acidity, temperature and alcoholic contents, as well as determination of survival times of major enteric pathogens in Takju. 1. Maximum number of Saccharomyces cerevisiae was $4.3{\times}10^7$ per milliliter on the 5th day of fermentation and gradually decreased. Saccharomyces cerevisiae was one of the predominant strains of the fermentation process. The number of Saccharomyces cerevisiae was $4.3{\times}10^6$ per milliliter at the completion of the brewing and human consumption. In a few days after the completion of the brewing. Bacillus subtilis and some species of Staphylococcus spp. began to grow and those organisms were responsible for the spoilage. 2. Maximum pH, during the brewing, was 5.8 on the first day of fermentation and rapidly decreased until 6th day of fermentation at pH 4.3. 3. Maximum alcholic content was 14.5 degree on the 4th day of fermentation, 10.3 degree on the 5th day and this degree was continued during the experimentation. 4. Maximum temperature, during Takju brewing was 34.deg.C on the 3rd day of fermentation and rapidly decreased up to 23.deg.C on the 6th day and this temperature was continued until the brewing process was finished. 5. Maximum total acidity was 0.57 percent on the 4th day of fermentation and gradually decreased by brewing process was completed. 6. Survival time of major enteric pathogenic bacteria in Takju was as follows : Shigella dysenteriae and Escherichia coli were isolated in two hours and 14 hours respectively, but Salmonella typhi, Vibrio parahemolyticus were not isolated even in an hour after the inoculation of those organisms in undiluted Takju. In diluted Takju, Salmonella typhi, Vibrio parahemolyticus were not isolated even in an hour after the inoculation of those organisms in undiluted Takju. In diluted Takju, Salmonella typhi, Shigella dysenteriae, and Escherichia coli were survived for 50-60 hours, but Vibrio cholerae and Vibrio parahemolyticus were not isolated even if treated within one hour.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.181-187
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• 1995

The cells of Vibrio vulnificus can be induced to the viable but nonculturable (VBNC) state by natural environmental parameters. The V. vulnificus cells in the VBNC state can not be recovered by ordinary laboratory techniques. This nonculturability could often hamper development of effective processing strategies to minimize the number of V. vulnificus in seafoods. Even with V. vulnificus cells in a culturable state, the length of time required to identify the bacteria in contaminated food by phenotyphic characterization may prevent appropriate in-time responses by public health agencies to infections of the bacteria. In the present study, we used polymerase chain reaction (PCR) to develop a rapid and direct detection method for V. vulnificus in small octopus (Octopus variabilis) which is consumed as a raw food in Korea. The region targeted was a 704-base pair (bp) portion of the hemolysin gene, vvhA, of V. vulnificus. The primers designed for PCR amplification were specific for all V. vulnificus sp. tested. Several methods were examined to extract total DNA directly from V. vulnificus seeded into the octopus homogenate and the guanidine isothiocyanate (CITC) method appeared to be most effective. From the octopus homogenate seeded by V. vulnificus at an initial level of $10^2$ CFU/ml of the homogenate and then incubated for 12 h, the targeted sequence was successfully amplified by PCR and the 704-bp DNA fragment was observed by gel electrophoresis. The total completion of this assay requires less than one day.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.229-230
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• 2022

According to the national building status, there are a total of 2.89 million buildings that are over 30 years old after completion, and the number is increasing by more than 70,000 to 80,000 buildings every year. As a result, the demand for demolition works is also increasing, and more than 3 to 4 collapse accidents occur steadily every year during demolition work. Major causes of accidents include non-compliance with plans, negligence of on-site supervisors, and failure to secure structural safety. Due to the strengthening of the Severe Disaster Punishment Act, there is growing interest in the demand for secure management of collapse detection during demolition works. Therefore, this study aims to investigate the applicability of real-time safety monitoring systems using a total station capable of 3D automatic displacement measurement in building demolition work for securing structural safety by the load changes during the demolition process.

• The Journal of Industrial Distribution & Business
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• v.9 no.8
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• pp.35-40
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• 2018

Purpose - The purpose of this study is to conduct a monitoring study on the learning process of e-learning contents. This study has two research objectives. First, by conducting monitoring research on the learning process, we aim to explore the implications for content development that reflects future student needs. Second, we want to collect empirical basic data on the estimation of appropriate amount of learning. Research design, data, and methodology - This study is a case study of learner's learning process in e-learning. After completion of the study, an in-depth interview was made after conducting a test to measure the total amount of cognitive load and the level of engagement that occurred during the learning process. The tool used to measure cognitive load is NASA-TLX, a subjective cognitive load measurement method. In the monitoring process, we observe external phenomena such as page movement and mouse movement path, and identify cognitive activities such as Think-Aloud technique. Results - In the total of three research subjects, the two courses showed excess learning time compared to the learning time, and one course showed less learning time than the learning time. This gives the following implications for content development. First, it is necessary to consider the importance of selecting the target and contents level according to the level of the subject. Second, it is necessary to design the learner participation activity that meets the learning goal level and to calculate the appropriate time accordingly. Third, it is necessary to design appropriate learning support strategy according to the learning task. This should be considered in designing lessons. Fourth, it is necessary to revitalize contents design centered on learning activities such as simulation. Conclusions - The implications of the examination system are as follows. First, it can be confirmed that there is difficulty in calculating the amount of learning centered on learning time and securing objective objectivity. Second, it can be seen that there are various variables affecting the actual learning time in addition to the content amount. Third, there is a need for reviewing the system of examination of learning amount centered on 'learning time'.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.9
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• pp.4381-4389
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• 2016

Background: Surgery is the corner stone for the management of rectal cancer. The purpose of this study was to demonstrate the optimal time of surgical resection after the completion of neoadjuvant chemo-radiotherapy (CRT) in treatment of locally advanced rectal cancer. Materials and Methods: This study compared 2 groups of patients with locally advanced rectal cancer, treated with neoadjuvant CRT followed by surgical resection either 6-8 weeks or 9-14 weeks after the completion of chemo-radiotherapy. The impact of delaying surgery was tested in comparison to early surgical resection after completion of chemo-radiotherapy. Results: The total significant response rate that could result in functional preservation was estimated to be 3.85% in group I and 15.4% in group II. Some 9.62% of our patients had residual malignant cells at one cm surgical margin. All those patients with positive margins at one cm were in group I (19.23%). There was less operative time in group II, but the difference between both groups was statistically insignificant (P=0.845). The difference between both groups regarding operative blood loss and intra operative blood transfusion was significantly less in group II (P=0.044). There was no statistically significant difference between both groups regarding the intra operative complications (P=0.609). The current study showed significantly less post-operative hospital stay period, and less post-operative wound infection in group II (P=0.012 and 0.017). The current study showed more tumor regression and necrosis in group II with a highly significant main effect of time F=61.7 (P<0.001). Pathological TN stage indicated better pathological tumor response in group II (P=0.04). The current study showed recurrence free survival for all cases at 18 months of 84.2%. In group I, survival rate at the same duration was 73.8%, however none of group II cases had local recurrence (censored) (P=0.031). Disease free survival (DFS) during the same duration (18 months) was 69.4 % for patients in group I and 82.3% for group II (P=0.429). Conclusions: Surgical resection delay up to 9-14 weeks after chemo-radiation was associated with better outcome and better recurrence free survival.

• Tunnel and Underground Space
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• v.9 no.1
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• pp.20-26
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• 1999

The completion of the Bakun Diversion Tunnel is subsequently to the Main Dam construction. Therefore, the completion date is very important for the Bakun Hydroelectric Project. Generally, the tunnel lining work as a finishing phase of the tunnelling project occupies a important portion as well as an excavation and a support work of the tunnels in respect to the construction cost and period. Internal section of Bakun Diversion Tunnel is designed circular shape to reduce the roughness of the water flow with 12 meters in diameter of total length 4314.6 meters of 3 tunnels. The lining thickness is varied between 500 mm and 700 mm depending on the structural condition. From the original Tender design of the Bakun tunnels, the required quantity of steel bars was 5,985 ton designed by Reinforced Concrete (RC) through the entire tunnel linings. During the detail design stage by the consideration of the rock conditions and various load conditions, we could suggest five kinds of RC lining type including plain concrete lining type. Through the detail design modification, we could reduce the required amount of steel bars to 2,178 ton, as a half of original Bill of Quantity. Finally, this design modification give us the time and cost saving effect to catch up the construction progress in time.

• PNF and Movement
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• v.17 no.2
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• pp.275-282
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• 2019

Purpose: This study aimed to investigate the optimal positions of safety grab bars for effective sit-to-stand (STS) movement by comparing the results of the STS movement while using a safety grab bar installed under two different conditions: the height of the grab bar installation was determined by (1) the Building Act and (2) the principle of proprioceptive neuromuscular facilitation (PNF). Methods: A total of 50 undergraduate students participated in this study, and they were required to perform an STS movement twice under each condition. A baropodometric platform for sitting and a Biorescue (RM Ingenierie, France) were used to collect and analyze changes in the center of pressure (COP) on the left and right sides before and after performing the STS movement. The average completion time for the STS movement was also measured for analysis. Moreover, the participants were asked to express their individual subjective preferences regarding the two positions of the grab bars. Results: The COP changes were significantly smaller when performing the STS movement with the grab bar installed at the height determined by the PNF principle than the Building Act (p<0.01), and the difference in the completion time of the STS movement was not statistically significant between the two conditions. Conclusion: The findings of this study suggest that the principle of PNF can be useful for planning therapeutic exercise as well as for proposing the optimal grab bar position for older adults and those with health-related issues when performing the STS movement. In addition, this may serve as a basic rehabilitation technique for maintaining remaining functions and providing functional efficiency.