• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.29-46
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• 2002

This study focuses primarily on the construction of the wartime sealift operation model from US to Korea. There are some uncertainties in the process of sealift operation such as the procurement rate of materiel in US, the distribution of KFS on four initial position locations at the start of the activation, and the number of ports and berths in the SPOES and SPODS. The sealift capability, based on the allocation of sealift assets such as the number of vessels, berths, and ports, is evaluated through simulation. The simulation is executed with a baseline wartime scenario and then the results are analyzed through a sensitivity analysis. The military planner may use of this model as a standard for establishing effective and concrete sealift operation plan in the near future.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.2
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• pp.231-238
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• 2011

A role of Distribution Automation System(DAS) is required to be changed from observing and control to complex and various new system including functions which monitoring, control, prediction, operation and management of EMS type according to be gradually Smart Grid of distribution operation system for development of further power system industrial. IEC(International Electrotechnical Commission) published communication standards which interface and data model of distribution operation system to IEC 61968 and of host system like EMS(Energy Management System) to IEC 61970. So far, each standards are emphasizing themselves, but if they are applied by designed integration of the standards, it could be more efficiency system. So, in this paper, integration application of IEC standards and structure of further distribution operation system to use them are proposed by gradually increasing importance of communication protocols, functions and roles in further distribution management system considering Smart Grid.

• Journal of Navigation and Port Research
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• v.36 no.2
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• pp.105-112
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• 2012

In order to improve the existing S-57 standard, International Hydrographic Organization(IHO) has developed S-100 standard, a Universal Hydrographic Data Model(UHDM) expanded from ISO 19100 series standard to hydrographic area, and is in the process of its implementation. International Maritime Organization(IMO) has established CMDS based on e-Navigation strategy data standard as International Association of Lighthouse Authorities(IALA) established IHDM based on aids to navigation data standard and each data standard is linked with the S-100 standard. Fundamental concept and core principles of S-100 standard is suitable not only for the development of a wide range of hydrographic data and service production standard, including the next generation ENC, but also the development of product specification of non-hydrographic area. This study has examined the operation principle of S-100 standard and analyzed its implementation process as e-Navigation data in relation with ENC. It also noted the utilization of S-100 standard based e-Navigation and its potential effect via examining the development cases of S-100 standard-based product specification, such as nautical publication, ship reporting and pilot request, digital routing guide, tide and water level transmission and other important data cases of e-Navigation field.

• Journal of Biosystems Engineering
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• v.20 no.1
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• pp.3-12
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• 1995

This study was conducted to investigate the cutting mechanism of the reciprocating knife of combine harvester. The cutting operation of reciprocating knife was demonstrated through the cutting pattern diagram which was drawn by computer graphics. Various kinds and dimensions of standard-type reciprocating knives were analyzed by the developed program. The results are summarized as follows : (1) For the 50mm standard reciprocating knife, the bunching area and the maximum stalk-deflection were decreased rapidly according to the increase of cutting velocity ratio by 1.0 and decreased very slowly over this ratio. But, the secondary cut was occurred at ratio of 1.0 and increased rapidly over this ratio. (2) The 76mm standard knife showed better cutting mechanism than the 50mm, in two respects : the larger cutting area per one stroke and the lower revolutional speed of crank shaft for the same cutting velocity. (3) In respect to the bunching area and the secondary cutting length, the adequate height of 50mm standard reciprocating knife was 45~50mm. (4) In order to maintain the proper cutting mechanism, the adequate cutting velocity at forward speed of 0.5㎧ to 1.2m/s was from 0.4m/s to 1.2m/s for the standard knife.

• Journal of Korean Society of Forest Science
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• v.80 no.2
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• pp.220-231
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• 1991

The main purpose of this research is to standardize the logging operation with special reference to the net working time for thinning. This study was carried out to obtain the standard working method and working technique for Korean logging operation through the comparison of the present Korean working method and the German standard working method 1. The net working time devided into work elements showed little difference between those two working methods. 2. From the correlation analysis, net working time was significantly correlated with breast height diameter, the dependant variable, with the highest correlation coefficient in each species. 3. Total working time increases by 11 to 13 seconds to every 1 centimeter increase in breast height diameter from i to 16 centimeter. 4. The result of this study concluded that the German working method is recommended for improving the labour problems in the forest operation due to high wages and lack of manpower gradually increasing from now in Korea. In addition to the application of this standard working method, the technical training for the method should be done to the workers for improving the productivity.

• Journal of the Korean Society of Safety
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• v.35 no.1
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• pp.12-17
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• 2020

This paper analyzes functions of component parts of D-Urban Railway's door system along with operation obstacle risks on frequency(the number of occurrences/year) and severity(delay time/the number of occurrences). Based on this, the paper presents improvements and current system's problems after obstacle risks of EMU and door system are appled. The obstacle of door system causes corrosion of main parts such as DCU due to heat problem of operation environment, problems of maintenance methods and deterioration. DCUs on PCBs with more than 50% pattern corrosion cause problems. Even though the number of door system's obstacle occurrences for the last 5 years is 42, along with 104 minutes of operation obstacle, EMU operation obstacle risk is low(Level 1), which indicates there is limit in matrix of railway risks presented by the standard of railway safety management system. Therefore, it is necessary to have railway risk matrix suitable for the field. Finally, the paper deducts the obstacle risks through frequency and severity. Since 2017 when the risks of EMU and door system's obstacle, that of EMU has been 24(47% reduced) and that of door system has been average 9.5 per year(23% reduced).

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.2
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• pp.132-143
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• 2011

This paper deals with a coal supply planning problem for power plants. We propose a mathematical optimization model to make decisions for coal pile sections, movement of reclaimers, and operation time of conveyor belts. The objective of the proposed model is to minimize the total operation time of conveyor belts and total movement time of reclaimers. The algorithm firstly selects a pile section by considering both the location of reclaimers and the stock amount on that pile section. And then the shortest path from the selected pile section has to be put into the operation schedule and check whether the total operation time is satisfied. Then finally the new schedule is updated. To this end, we have tested the proposed algorithm comparing with the general standard optimization package for the simplified problem SCSPP. From the numerous test runs for comparing with the existing coal supply scheduling methods, We see that the proposed model may improve the coal supply operation by reducing significant coal supply costs.

• Journal of Korean Society of Water and Wastewater
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• v.24 no.6
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• pp.735-741
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• 2010

A pilot test was carried out to investigate the long term operation characteristics of Microfiltration (MF) system as a pretreatment for seawater reverse osmosis (SWRO) processes for two years. A commercialized MF module with pressurized operation type was used to filter seawater to remove particles which can foul reverse osmosis (RO) membrane. Silt Density Index (SDI) values of filtered seawater by the MF system were ranged from 0.14 to 1.79, which meet the SDI standard for RO feed water as depicted in previous literatures. Although the tested seawater is quite clean (i.e., dissolved organic cabon (DOC) concentration and turbidity were about 1 mg/l and less than 1 NTU, respectively) enough not to foul the MF membrane, steep increase in trans-membrane pressure (TMP) with a constant flux were observed over a whole operation period. A set of operation and water analysis data implies that the steep increase in TMP was resulted from iron and maganese fouling by the combination of metal corrosion by seawater and oxidation state by aeration and residual chlorine.

• Advances in pediatric surgery
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• v.7 no.2
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• pp.137-141
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• 2001

Thyroglossal duct cyst is ectodermal remnant, which may develop along the line of descent of the thyroid gland from the foramen cecum of the tongue to the pyramidal lobe of the thyroid gland. Meticulous dissection of the cyst and duct, along with the body of the hyoid bone is necessary to avoid recurrence. Eighty-one patients with thyroglossal duct cyst treated at Hanyang University Hospital between January 1980 and December 2000 were reviewed to determine the incidence and to analyze the result of management. The male-to-female ratio was 1.4:1(47:34) with a male preponderance. They are most commonly present at 3-8years(54.2 %) of age, but rarely present at infancy. The most common symptom was a painless midline neck mass(76.5 %, 62cases). Eighty-one patients underwent modified Sistrunk operation without evidence of recurrence. Eight-nine percent(72 cases) of these lesions were located between thyroid substance and hyoid bone, and 11 %(9 cases) were above the hyoid bone. There were 22 infected cysts(27.2 %). The Sistrunk operation is a gold standard for treating the thyroglossal duct cysts. For best results in thyroglossal duct cyst surgery, one should make every effort to remove the cyst intact in continuity with the body of the hyoid bone. In our institute, Sistrunk operation modified by the authors showed a good result.

• Journal of Internet Computing and Services
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• v.12 no.1
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• pp.131-139
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• 2011

The purpose of this research is to evaluate patient's satisfaction and clinician' knowledge level about pain, nausea, vomiting, and temperature management of patients after operation by develop an web-based evidence-based practice guideline about pain, nausea, vomiting, and temperature control after operation in order to apply the guideline operation patients. The collected data was analyzed through real number, average, standard deviation, t-test and repeated ANOVA by using SPSS/WIN 17.0 program. The study subjects showed a significant difference in the level of knowledge about pain, nausea/vomiting, and temperature control after operation and patient's satisfaction, before and after applying the web-based evidence-based practice guideline.