• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.11a
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• pp.267-270
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• 2018

해상교통관제센터(VTS)는 해상 안전과 선박교통효율을 위해 우리나라 주요 항만 및 연안해역에서 운용중이다. 우리나라 VTS는 외국항만 VTS에 비해 1인당 담당 관제면적이 넓으며, 최근 VTS 구역 추가 확대로 기존 관제사의 담당구역이 기존보다 더욱 확대되어 관제사의 집중관제와 선박교통관리 어려움이 더욱 증가되고 있다. 이에 따라 VTS 구역의 효율적인 운영과 VTS 인력 확보를 위한 정량적인 관제석 수 산출이 필요하다. 본 연구에서는 VTS에서 수집중인 선박교통 및 선박교신 데이터를 이용하여 VTS 구역 적정 관제석 산출방법을 제안하고자 한다. 제안한 방법은 VTS 구역에서 운항하는 모든 선박의 모니터링 시간, VHF 교신에 대하여 관제 업무(task)항목, 출현빈도, 소요시간을 정의하고, 단위시간동안 각 관제 task별 소요시간을 계산하여 관제석 수를 계산한다. 제안한 방법을 여수VTS 해역의 VTS데이터에 적용하여 적정 VTS 관제석 수, 시간대별 관제석 수 변화를 분석하였다. 분석 결과 혼잡시간대 필요 관제석이 4-5 석이 필요로 한 것으로 분석되었다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.223-230
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• 2006

The reliability of imprint patterns molded by stamps for industrial application of nanoimprint lithography (NIL), is an important issue. Usually, defects can be produced by incomplete filling of negative patterns and the shrinkage phenomenon of polymers in conventional NIL. In this paper, the patterns that undergo a varied temperature or varied pressure period during the thermal NIL process have been investigated, with the goal of resolving the shrinkage and defective filling problems of polymers. The effects on the formation of polymer patterns in several profiles of imprint processes are also studied. Consequently, it is observed that more precise patterns are formed by the varied temperature (VT-NIL) or varied pressure (VP-NIL). The NIL (VT-NIL or VP-NIL) process has a free space compensation effect on the polymers in stamp cavities. From the results of the experiments, the polymer's filling capability can be improved. The VT-NIL is merged with the VP-NIL for the better filling property. The patterns that have been imprinted in the merged NIL are compared with the results of conventional NIL. In this study, the improvement in the reliability for results of thermal NIL has been achieved.

• Journal of Korean Academy of Nursing
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• v.30 no.4
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• pp.995-1005
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• 2000

This study was performed to identify the physiological and psychological variables related to successful weaning from a mechanical ventilator. The subjects of this study were 22 patients who received mechanical ventilation therapy for more than 3 days in intensive care units. Before the weaning trial, baseline data for following physiologic variables were obtained: spontaneous respiration rate, blood pressure, pulse rate, PaO2, PaCO2, PEEP, static compliance, minute ventilation, tidal volume, rapid shallow breathing index(f/VT), SaO2, PaO2/FiO2 and mean arterial pressure. During spontaneous breathing, physiologic and psychologic variables such as vital signs, ABG, perspiration, chest retraction, paradoxical respiration, dyspnea, anxiety, confidence and efficacy were measured. Successful weaning was defined as sustaining spontaneous respiration over 24 hours after extubation. Weaning failure was defined as the development of more than one of following signs: (1) hypoxemia, (2) CO2 retention or (3) perspiration, tachypnea, chest retraction, tachycardia, arrhythmia, hypotension or hypertension. Subjects (N=18) who successfully weaned from mechanical ventilator were compared with subjects (N=4) who failed. The results are as follows; Eighteen percents of the subjects failed during the weaning trial. Most subjects in the failed group were mechanically ventilated for long-time. This result shows that the success of weaning is more difficult in long-term ventilation patients. In the baseline data that was measured before weaning trial, the mean score of PaO2 in the successfully weaned group was 121mmHg. This is significantly higher than the mean score of PaO2 in the failed group(95mmHg). However, the scores of pH, tidal volume, f/VT, pulse rates, blood pressure, mean airway pressure, SaO2, and PaCO2 were similar between the two groups. Specially the scores of f/VT index as a predominant predictor for successful weaning were not significant (f/VT=44.4) and (f/VT=47). During spontaneous breathing, the scores of dyspnea and anxiety level in the successfully weaned group were less than those of the failed group. On the contrary, the scores of confidence and efficacy in the successful group were greater than those of the failed group. In conclusion, the baseline data that were measured before weaning trial were similar between the both groups, therefore future studies are needed to focus on searching other variables besides physiological parameters related to weaning outcome.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.406-412
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• 1998

The endoglucanase gene, egl6, of Trichoderma sp. was connected with the yeast ADH1 promoter, and the resultant plasmid, pVT-C4, was introduced into three S. cerevisiae host strains (YNN27, 2805, and SEY2102). Among each 80 transformants, the cell growth and expression level of endoglucanase were compared in test-tube cultivation, and three respective transformants for each host cells showing the highest expression level and cell growth were selected. When three recombinant yeast cells were batchwise cultivated for 48 hr in flask, the total activities of endoglucanase expressed were about 1140 unit/l with 2805/pVT-C4, 1020 unit/l with SEY2102/pVT-C4, and 590 unit/l with YNN27/pVT-C4. Irrespective of host strain, about 80% of the expressed endoglucanase was detected in the extracellular medium. In addition, it was also found that the recombinant enzyme was secreted into the culture medium as two major forms of lightly and heavily glycosylated proteins.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.12
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• pp.5789-5796
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• 2011

This study examined the effect of VT(Vibration Training) on the symptoms of DOMS (Delayed-Onset Muscle Soreness) before induced by eccentric exercise of the left leg triceps surae. Twenty one healthy adult men and women who had not participated in a regular exercise program for the lower extremities were assigned to one of two experimental groups: vibration training group, Control group. We measured the VAS(Visual Analogue Scale), ankle plantar flexor strength, triceps surae circumference, CK(Creatine Kinase) before and after exercise and 24, 48 and 72 hours after eccentric exercise. After inducing DOMS, VAS showed significant differences between groups at a point of time 48 hours, and showed significant differences within groups in accordance with the time of measurement(p<.05). Plantar flexor strength of groups with VT did not show significant difference between groups but, showed significant differences within groups in accordance with the time of measurement(p<.05). Triceps surae circumference of groups with VT did not show significant difference between groups but, showed significant differences within groups in accordance with the time of measurement(p<.05). CK of groups with VT did not show significant difference between groups but, showed significant differences within groups in accordance with the time of measurement(p<.05). As a result of the study, VT prior to eccentric exercise is effective to inhibit pain. So, this method can be suggested to prevent DOMS in doing an unfamiliar activites.

• Journal of Chest Surgery
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• v.29 no.6
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• pp.639-645
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• 1996

A 14-year-old male patient with previous surgical repair of tetralogy of Fallot was admitted with hemodynamically significant ventricular tachycardia (VT). On preoperative electrophysiologic study (EPS), the morphology of documented VT was RBBB of vertical axis with 320 msec cycle length. The endocardial mapping during VT delineated the origin of VT at right ventricular outflow tract (RVOT), where the patch was attached. The clinical VT had a clockwise reentry circuit around the patch with the earliest activation at the same site seen during the preoperative EPS. The previously placed right ventricular outflow patch and fibrous tissue were removed. During a postoperative EPS, it was no longer possible to induce the VT. Ventricular tachycardia following repair of tetralogy of Fallot seen in this patient was caused by a macro-reentry around the right ventricular outflow patch. We were able to ablate the VT with the aid of a detailed mapping of its epicardial activation sequence.

• Defense and Technology
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• no.1 s.239
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• pp.20-23
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• 1999

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.243-245
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• 1998

미래의 셀룰라 이동통신망은 멀티미디어 데이터 서빗를 제공하기 위해서 높은 대역폭이 필요하기 때문에 셀의 크기가 수십 미터 내오인 피코 실(pico cell)로 구성되는 피코 셀 망이 될 것이다. 이와 같은 피코 셀룰라 망에서는 이동통신자의 우치 변화에 따른 handoff 처리 회수가 상대적으로 증가하므로, handoff 처리로 인한 망부하가 늘어났고, handoff처리 지연으로 인하여 사용자는 중단없는 연결서비스 (seamless connection service)를 받지 못할 수도 있다. 본 논문은 VT-CSMA방식을 응용한 기법을 새로운 handoff방식으로 제안한다. 이 기법은 handoff에서 사용하고 delay time virtual clock 과 real clock 의 2개의 clock을 갖도록 함으로써, 빠른 속도로 이동하는 호는 느린 속도로 이동하는 호보다 상대적으로 짧은 시간 내에 handoff가 처리 되도록 한다. 모의 실험 결과는 VT-CSMA기법을 응용한 새로운 방식이 기존 CDMA 방식에서 drop되는 호를 많이 줄이는 효과가 있음을 보인다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.197-199
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• 2010

해상교통관제는 선박 통항의 안전과 효율성을 증진시키고 환경을 보호하는데 큰 기여를 하였다. 이러한 성과를 바탕으로 현재는 선박이 항만으로 진입하기 이전 단계에서부터 미리 관제를 실시하여 해양사고의 위험을 사전에 방지하고자 관제범위가 확대되고 있는 추세이다. 이를 위해서는 통항 선박에 관련된 정보가 지속적으로 관리 유지되어야 한다. 본 연구에서는 항만 관제와 인근 관제 및 접근 관제와의 효율적인 연계 및 운영 방안을 집중적으로 검토하였다. IALA에서 논의되고 있는 IVEF(Inter-VTS Exchange Format) 및 광역 AIS망을 이용하여 인근 관제실 간에 관제정보를 연계하는 방안을 살펴보고, 관제실 및 유관기관 간에 정보의 원활한 공유를 통해서 관제수역의 확대에 따른 VTS의 효율적인 운영 방안을 모색하여 보았다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.152-154
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• 2010

VTS가 설치 및 운영되기 시작하여 해양사고의 수가 감소하였으나 최근 VTS 관제범위 내에서 주목할 만한 해양사고가 발생하고 있다. 이 연구에서는 VTS의 역량강화를 위한 방안으로 해상교통관제사 자격제도를 도입하는데 있어서 필요한 직무분석을 실시하고 자격을 갖추는데 필요한 지식과 기술에 대한 비중을 분석하였다. 현재 관제업무에 종사하고 있는 해상교통관제사를 대상으로 설문조사를 실시하고 결과를 분석하여 해상교통관제사의 자격제도, 교육훈련 및 평가제도의 연계방안을 수립하는데 도움이 되고자 한다.