• Journal of Korean Neurosurgical Society
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• v.29 no.1
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• pp.35-43
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• 2000

Objective : Percutaneous lumbar approaches such as arthroscopic discectomy, laser discectomy, and nucleotome remain controversial and have technical limitations to free fragment disc, bony pathology and access to L5-S1, The purpose of this study was to determine efficacy of this new endoscopic system and to report techniques and tactics. Methods : From July 1997 to May 1998, we treated 40 consecutive patients(43 levels) with the MED system. Mean age was 32 years(range ; 18 to 62). There were 30 males and 10 females. All patients had sciatica with SLRT limitation. There were 23 patients with disc herniation at L4-5 and 14 patients at L5-S1. Three patients had 2 level disc herniations. There was one far lateral disc herniation at L4-5. Results : Using modified MacNab criteria, there were 37 excellent results and 3 good result. Most patients were discharged within 3-4 days except 2 patients with dural tearing. There were no other complications. Mean operation time was 1.5 hours(range : 40 minutes to 2.5 hours). Conclusion : The MED system is a reliable approach to lumbar disc herniations. This system combines the advantages of conventional open surgery and a minimally invasive technique. As tactics for the doctors who wish to attempt, "palpate" the lamina by first dilator, identification of interlaminar space by removal of overlying soft tissue and confirmation of the shoulder portion of nerve root before discectomy are important to this procedure. We conclude that lumbar disc herniations can be successfully treated with MED approach.

• Korean Chemical Engineering Research
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• v.58 no.4
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• pp.604-609
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• 2020

The purpose of this study is to check the priority control status of the current operation process alarm by comparing the priority of the alarm set up in PV high trip point, which is being installed and operated in the domestic petrochemical industry, with the criteria presented in ISA 18.2 International Standard or EEMUA 191 Guidelines. In the event of a process problem, excessively set high alarm is provided to the driver in a short period of time, making it difficult to identify the alarm that needs to be handled first. As a result, it is likely that the operator will not be able to carry out appropriate actions within the specified time frame, and many cases have been reported leading to unexpected process shutdowns or process accidents. Therefore, this study aims to introduce international standards related to alarm management and identify the level of alarm control used at the domestic petrochemical industry site to inform potential risks that may occur in the petrochemical process of the national industrial complex in the future and suggest ways to reduce risk factors. This paper was submitted to Professor Lee Inbeom's retirement anniversary issue.

• Journal of Aerospace System Engineering
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• v.14 no.1
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• pp.54-61
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• 2020

For operating military aircraft, military certificate of airworthiness (MCA) must be obtained from military authority. Among procedures of general airworthiness certification, there is a military type certification process that aircraft design complies with military airworthiness certification criteria. The Surion is the first military rotorcraft which has obtained military type certificate, production validation and airworthiness certificate in Korea, and the Surion derivatives for special mission are being operated for government services. Based on Aviation Safety Act, in order to operate the Surion derivatives (military aircraft) for special purpose (such as emergency patient transportation and firefighting), the issuance of special airworthiness certificates was needed from civil airworthiness authority, and the restricted category type certification (RTC) is one of design approvals for special airworthiness certification to be streamlined. This study discussed the procedures for acquiring RTC for special purpose operation of the Surion derivatives classified as military derived aircraft, and suggested procedural ideas to improve Korean RTC system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.497-503
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• 2018

Passenger ships and training ships have a common feature in that they serve many passengers. Thus, safe navigation is very important. During normal sailing, a ship may turn using various types of steering, including maneuvers to avoid collisions with dangerous target. When a ship turns, a heeling angle occurs. If trouble arises during sailing, a dangerous heeling angle may result or a capsizing accident. In this study, the heeling angle during turning was measured through experimentation with two training ships similar to passenger ships. These findings were compared with theoretical formulas for heeling angle when turning. We confirmed that the limit of the maximum heeling angle estimation using heeling angle formula when turning presented in IMO stability criteria. In addition, it was confirmed that the maximum estimated heeling angle can be reached by applying the result calculated in the theoretical formula 1.4 times when turning right and 1.1 times when turning left to reflect sailing speed when of rudder hard over. It is expected that this study will provide basis data for establishing safe operation standards for the prevention of dangerous heeling angles when turning.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.4
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• pp.309-316
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• 2020

Waterway design should prioritize appropriate channel width to ensure preferential safe passage for the arrival and departure of vessels. To calculate the minimum channel width required for safe passage a comprehensive review of several factors is required. These factors include vessel maneuverability, determined by vessel size, type and speed; environmental factors such as wind, tide, and wave action; human factors, including personal experience and operator judgment as well as marine traffic and navigation support facilities for decision making. However, the Korean channel width design standard is based only on vessel length, and requires improvement when compared with the standards of PIANC, USA, and Japan. This study aims to estimate the appropriate channel width required for one-way traffic in a straight channel, considering various vessel and environmental factors, using Fast Time Simulation (FTS). When the wind speed is 25 knots, with a current speed of 2 knots and a normal vessel speed of 10 knots FTS shows that a 150K GT Cruise Ship requires a minimum channel width of 0.67-0.91 the vessel length (L), whereas a 120K TEU Container Ship and a 300K DWT VLCC require 0.79-1.17 and 1.02-1.59, respectively. Such results can be used to calculate the minimum channel width required for safe passage as an improved Korean design standard.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.13 no.5
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• pp.1-10
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• 2014

This research focuses on the warrants for the Two-Way Left-Turn Lanes (TWLTL). Using a microscopic traffic simulation tool, two key parameters were investigated herewith. One is a wide range of the Design Hourly Volume (DHV), reflective of recent Korean roadway volume characteristics, that is conventionally reduced from the Average Daily Traffic (ADT). The other is driveway spacing, the length of the middle-lane section where two conflicting left-turn demands often compete for space. In addition, unlike previous researches, the way and the procedure the TWLTL operation is realized in the VISSIM S/W with its add-on application such as VISVAP is clearly stated and described in detail. According to the result of simulations for 10 volume scenarios, as expected, the higher the volume level is, the more delay the left-tuner experience. The Level Of Service (LOS) for most cases was in the range of C and D based on the non-signalized intersection LOS criteria. Furthermore, the TWLTL was found operable up to the volume level of 1,116 and 1,860 vph in heavy direction (equivalent of volume level 7) for 3-lane and 5-lane facility respectively, which covers significant portion of existing two to four-lane highway volumes in Korea.

• Journal of Korean Home Economics Education Association
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• v.29 no.4
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• pp.65-84
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• 2017

The purpose of this study is to activate Home Economics integrated career education for strengthening career development competency in a career education intensive semester & grade system. To do this, the trend of subjects-integrated career education, and the relationship between achievement standards of Home Economics in high school and career development competency were analyzed, methods for Home Economics subjects-integrated career education were investigated, then a case study was developed. The main research results of this study are as follows. First despite the importance of subjects-integrated career education, there are much rooms to improve in operation of the career education intensive semester & grade system. Therefore, the systematic preparation for subjects-integrated career education is required at the time of application of the 2015 revised curriculum and the expansion of the career education intensive semester & grade system. Second, all achievement criteria in three domains of Home Economics were shown to be highly related to career development competency. Eventually it could be confirmed that the Home Economics is a core subject that meets the goals of career education and hones career development competency to be prepared as future human resources. Finally, in order to strengthen the career development competency, a case study of Home Economics integrated career curriculum focusing on the association with curriculum-teaching & learning-evaluation was developed and proposed. Even though the developed case study of curriculum has not been proven yet in the class, this study is expected to contribute to the enlargement of career education of Home Economics in the career education intensive semester & grade system as fundamental data for integration of Home Economics and career education.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.1 s.2
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• pp.41-52
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• 2003

The purpose of this study was to test the effects of the pedestrian green signal adjustment on clearance of the turning vehicles impeding the through traffic flow at the signalized intersections, and thereby, suggest some operational criteria for adjustment of the pedestrian green signal. In order to test such effects, the pedestrian green time was adjusted so that it could started a few seconds later than the vehicle green time during peak hours, and thereby, the turning vehicle volume not cleared at the intersection was measured by extending the time gap by 2 seconds. (In general, the pedestrian green signal turns on at the same time as the vehicle green signal.) The results of this test can be summed up as follows; first, the longer the time gap was, the turning vehicle volume not cleared from the intersection decreased more. Second, in case there existed a storage space between intersection and crosswalk the effect of the turning vehicles on the through traffic flows was minimal. Third, at the pelican, the effect of the turning vehicles on the through traffic flow was minimal due to the structure of the intersection and the phase sequence. In conclusion, it was found that the adjustment of pedestrian green signal had the effect of enhancing the intersection operation. When adjusting the pedestrian green signal, it was deemed necessary to thoroughly survey the geometric structure of the intersection and collect the data on the turning traffic volume and thereby, apply the results of analysis flexibly to each intersection.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.5
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• pp.207-216
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• 2013

Objectives: The purpose of this study is to analyze clinical impact factors on the survival rate, and to acquire basic clinical data for the diagnosis of oral cancer, for a determination of the treatment plan with long-term survival in oral cancer patients. Materials and Methods: Through a retrospective review of the medical records, the factors for long-term survival rate were analyzed. Thirty-seven patients, among patient database with oral cancer treated in the Department of Oral and Maxillofacial Surgery at Pusan National University Hospital within a period from March 1998 to March 2008, were selected within the study criteria and were followed-up for more than 5 years. The analyzed factors were gender, age, drinking, smoking, primary tumor site, type of cancer, TNM stage, recurrence of affected region, and metastasis of cervical lymph node. The 5-year survival rate on the impact factors was calculated statistically using the Kaplan-Meier method. Results: By classification of clinical TNM at the 1st visit, there were 11 (29.7%) cases for stage I, 11 (29.7%) cases for stage II, 3 (8.1%) cases for stage III, and 12 (32.5%) cases for stage IV. The 5-year survival rate of total oral cancer patients after the operation were 75.7%, pathological TNM stage related 5-year survival rate were as follows: stage I 90.0%, stage II 81.8%, stage III 100% and stage IV 45.5%; in which the survival rate difference by each stage was significantly observed. The recurrence of cervical lymph node was the significant impact factor for the survival rate, because only 30.0% the survival rate in recurrent cases existed. During the follow-up, there were 15 (40.5%) patients with confirmed recurrence, and the 5-year survival rate of these patients was decreased as 46.7%. Conclusion: The classification of clinical and pathological TNM stage, local recurrence after surgery, and metastasis of cervical lymph node after surgery were analyzed as the 3 most significant factors.

• Korean Journal of Social Welfare
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• v.36
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• pp.147-173
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• 1998

The purpose of this study was to investigate the current status and problems of the social service delivery system for women in Korea, and to suggest ways to improve its function. The current social service delivery system in the public sector contains a network of services connected with the Division of Women's Welfare in the Ministry of Health and Social Welfare. This study focused on evaluating the function of the public service delivery system from the perspective of the service providers. A survey of 167 civil officers in charge of women's welfare services in the city.county.district administrations, and 202 women's welfare counselors around the country was conducted in order to evaluate their current duties, effectiveness of services, and problems of the current system Six criteria including integration, continuity, accessibility, adequacy, efforts and professionalism were used for evaluating the effectiveness of the social service delivery system for women. According to the survey, the civil officers and women's counselors gave relatively favorable ratings for their job effectiveness and job satisfaction. However, their duties involving guidance and counseling of prostitute women and operation of women's welfare councils received least favorable evaluation. Moreover, in terms for job satisfaction, these service providers were less satisfied with their working conditions than their relationships with clients or colleagues. In addition, budget and personnel shortages were the most serious problems facing the delivery system Further analysis showed that professionalism and accessibility of the service delivery system had positive impact on job effectiveness while efforts, integration, accessibility and adequacy had positive impact on job satisfaction of the service providers. These findings have potential implications for designing more effective social service delivery system for women.