• 한국신뢰성학회지:신뢰성응용연구
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• 제18권1호
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• pp.1-7
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• 2018

Purpose: Maintaining appropriate operational availability (Ao) is a key element of combat victory, but estimates vary according to estimation methods. The purpose of this study is to improve the accuracy of estimating operational availability by tracing the changes of the weapon system's failure rate, repair rate, and the level of logistic support. Methods: In order to track the change in the operating availability, the MDT (mean down time) is modeled by adding the repair time and the ALDT (administration and logistic delay time) to the service time. Results: Using the field data of the weapon system A operated by the ROKAF, the failure rate follows a non-homogeneous Poisson process that changes with time, and it is modeled considering the changing repair rate and the logistic support time. Conclusion: The accuracy of the analytical results was verified by comparing the actual operating data with the estimated availability. The results of this study can be used to track and evaluate the availability in a realistic situation where the failure rate and maintenance rate continuously change in operating environment.

• 한국콘텐츠학회논문지
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• 제6권10호
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• pp.114-125
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• 2006

이전 논문은 자바 프로그램에서 논리적인 오류를 찾기 위한 기술로 HDT를 제안했었다. HDT는 알고리즈믹 프로그램 디버깅 기술을 이용하여 실행트리에서 오류를 포함하고 있는 메소드를 찾고, 단계적 프로그램 디버깅 기술을 이용하여 오류를 포함하고 있는 메소드에서 오류가 있는 문장을 찾아낸다. 이 기술은 전통적인 디버깅 기술보다 자바 프로그램에서 프로그래머가 디버깅하는 횟수를 줄였다. 그러나 최근에는 프로그램 크기가 증가하고 메소드의 수가 증가하고 있기 때문에 아직까지 HDT는 디버깅하는 횟수가 많다. 이 논문은 HDT에 프로그램 분할 기술을 적용하는 HDTS를 제안한다. 이 방법은 자바 프로그램을 디버깅할 때, HDT보다 프로그래머가 디버깅하는 횟수를 줄여 줄 수 있다. 특히, HDTS는 메소드와 문장의 수가 증가할수록 효율성이 증가한다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2003년도 추계종합학술대회
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• pp.81-85
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• 2003

어업통신에서 출어선의 위치보고를 디지털화하여 VMS(Vessel Monitering system)를 구축하기 위하여는 체계적인 정보의 관리와 운용이 필요하다. 또한 위치정보의 체계적인 관리를 위해서는 먼저 정보의 권역화 및 집중화가 선행되어야 한다. 지역의 전파환경, 출어선의 조업해역, 어선세력, 트래픽량 등을 고려하여 권역을 구분하고, 권역별로 선위정보를 수집하여 이것을 본부에 집중하면 VMS의 DB를 구현할 수 있다. 본 논문에서는 VMS를 구축하기 위한 어업정보망의 구축과 어선의 위치정보를 자동으로 전송하는 방안에 대하여 연구하였다.

• 한국정보통신학회논문지
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• 제7권7호
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• pp.1387-1392
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• 2003

어업통신에서 출어선의 위치보고를 디지털화하여 VMS(Vessel Monitoring system)를 구축하기 위하여는 체계적인 정보의 관리와 운용이 필요하다. 또한 위치정보의 체계적인 관리를 위해서는 먼저 정보의 권역화 및 집중화가 선행되어야 한다. 지역의 전파환경, 출어선의 조업해역, 어선세력, 트래픽량 등을 고려하여 권역을 구분하고, 권역별로 선위정보를 수집하여 이것을 본부에 집중하면 VMS의 DB를 구현할 수 있다. 본 논문에서는 VMS를 구축하기 위한 어업정보망의 구축과 어선의 위치정보를 자동으로 전송하는 방안에 대하여 연구하였다.

• 한국컴퓨터정보학회논문지
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• 제28권9호
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• pp.121-128
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• 2023

무선 센서 네트워크에서 네트워크의 수명을 증가시키기 위해 주변 환경으로부터 에너지를 수집하거나, 무선 전력 전송으로 직접 에너지를 전달하는 방법이 사용되고 있다. 또한 에너지의 불균형을 줄이고 데이터의 수집량을 증가시키기 위해 직접 센서 노드를 방문해서 자료를 수집하는 모바일 싱크 노드를 활용한 방법이 사용되고 있다. 본 논문에서는 이러한 환경에서 각 센서 노드가 네트워크 환경과 에너지를 고려하여 Minimum Depth Tree (MDT)를 구성하고 자식 노드에 자료수집량을 할당해줌으로써 중계 노드의 부하를 줄이고 전체적으로 많은 데이터를 고르게 수집하는 기법을 제안한다. 시뮬레이션 결과, 본 기법은 기존의 다른 기법에 비해 에너지 고갈을 효과적으로 억제하고 더 많은 자료를 수집하는 것을 보여준다.

• 한국응용과학기술학회지
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• 제18권3호
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• pp.197-213
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• 2001

Conjugate trienoic acids (CTA) occurred in triacylglycerols (TGs) of the seed oils of Trichosanthes kirilowii, Momordica charantia and Aleurites fordii, and they were easily converted to their methyl esters in a mixture of sodium methoxide-methanol without any structural destruction. The main fatty acids in triacylglycerol (TG) fraction of the seed oils of Trichosanthes kirilowii are $C_{18:2{\omega}6}$ (32.2 mol %), $C_{18:3{\;}9c.11t,13c}$ (38.0 mol %) and $C_{18:1{\omega}9}$ (11.8 mol %), followed with $C_{16:0}$ (4.8 mol %) and $C_{18:0}$ (3.1 mol %). The TG fraction was resolved into 20 TG molecular species according to the partition number (PN) by reversed-phase (RP)-HPLC. The main TG species were $DT_{c2}$, $MDT_{c}$ and $D_{2}T_{c}$, of which amounts reached 63 mol % of total TG molecular species. The TG sample was fractionated into 11 fractions according to the number of double bond in the molecule by $Ag^{+}-HPLC$ and the species of $DT_{c2}$, $MDT_{c}$ and $D_{2}T_{c}$ were also eluted as main components. The TG species containing CTA showed unusual behaviours in the order of elution by HPLC ; first, TG moleular species of $DT_{c2}$ (D; dienoic acid, $T_{c}$; punicic acid, $T_{ci}$; ${\alpha}-eleostearic$ acid, M ; monoenoic acid, $S_{t}$; stearic acid) was eluted earlier than $Mt_{c2}$, although they have the same PN number of 40, and, secondly, the species of $DT_{ci2}$ with eight double bonds was eluted earlier than that of $D_2T_{ci}$ with seven double bonds. Intact TG of the seed oils of Momordica charantia contained mainly fatty acids such as $C_{18:3{\omega}9c,11t,13t}$ (57.7 mol %), $C_{18:1{\omega}9}$ (17.4 mol %), $C_{18:0}$ (12.3 mol %) and $C_{18:2{\omega}6}$ (10.6 mol %), and was classified into 13 fractions by RP-HPLC. The main TG species were as follows ; $MT_{ci2}$ [$(C_{18:1{\omega}9})(C_{18:3\;9c,11t,13t})_{2}$, 39.1 mol %] and $S_{t}T_{ci2}$ [$(C_{18:0})(C_{18:3\;9c,11t,13t})_2$, 33.9 mol %] comprising about 73 mol % of total TG species, accompanied by $DT_{ci2}$ [$(C_{18:2{\omega}6})(C_{18:3\;9c,11t,13t})_{2}$, 7.3 mol %], $D_{2}T_{ci}$ [$ (C_{18:2{\omega}6})_{2}(C_{18:3\;9c,11t,13t})$, 3.6 mol %] and $MDT_{ci}$ [$(C_{18:1{\omega}9})(C_{18:2{\omega}6})(C_{18:3\;9c,11t,13t})$, 3.5 mol %]. Simple TG species of $T_{ci3}$ [$(C_{18:3\;9c,11t,13t})_3]$ was present in a small amount of 1.4 mol %, but other simple TG species were not detected. The TG was also resolved into 11 fractions according to the number of double bond by $Ag^{+}-HPLC$, and the species were mainly occupied by $MT_{ci2}$ [$(C_{18:1{\omega}9})(C_{18:3\;9c,11t,13t})_{2}$, 39.4 mol %] and $S_tT-{ci2}$ [$(C_{18:0})(C_{18:3\;9c,11t,13t})_{2}$, 35.4 mol %] $DT_{ci2}$ species with eight double bonds was also developed faster than $D_2T_{ci}$ one with seven double bonds as indicated in the analysis of TG of the seed oils of T. kirilowii, and $MT_{ci2}$ species with cis, trans, trans-configurated double bond was eluted earlier than $MT_{c2}$ species with cis, trans, cis-configurated double bond. The main components of fatty acid in total TG fraction isolated from the seed oils of of Aleurites fordii were in the following order ; $C_{18:3\;9c,11t,13t}$ (81.2 mol %)> $C_{18:2{\omega}6}$ (8.5 mol %)> $C_{18:1{\omega}9}$ (5.4 mol %)$. With resolution of the TG by RP-HPLC, eight fractions such as $T_{ci3}$, $Dt_{ci2}$, $D_{2}T_{ci}$, $MT_{ci2}$, $PT_{ci2}$ (P; palmitic acid), $PMT_{ci}$, $PDT_{ci}$ and $S_{t}T_{ci2}$ ($S_{t}$; stearic acid) were isolated, respectively. TG species of $T_{ci3}$ [$(C_{18:3\;9c,11t,13t})_{3}$, 54.2 mol %], $DT_{ci2}$ [$(C_{18:2{\omega}6})(C_{18:3\;9c,11t,13t})_{2}$, 15.0 mol %] and $MT_{ci2}$ [$(C_{18:1{\omega}9})(C_{18:3 9c,11t,13t})_{2}$, 14.8 mol %] were present as main species.

• 한국정보통신학회논문지
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• 제7권1호
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• pp.26-33
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• 2003

어업무선국에서는 연안조업을 목적으로 약 10톤 미만의 소형어선과의 통신망으로 27MHz대의 주파수를 사용하는 SSB통신에 의존해 왔었다. 소형선박의 척수가 늘어나고, 어업통신본부에서는 각 도서지방을 무인화 시킴으로서 소형선박의 입ㆍ출항 및 조업사항을 관장해야 하는 통제 기능이 약화되기 시작했고, 현용 통신방식의 문제점이 드러나기 시작하면서 새로운 통신방식의 도입이 필요하게 되었다. 이들 선박은 SSB보다는 셀룰라폰을 그들의 주 통신망으로 사용하고 있으며 입ㆍ출항 신고는 물론이고 위치보고도 제대로 하지 않고 있는 실정이다. 또한 소형어선들은 항만 내외에서 운항거리를 단축하기 위해 주항로를 횡단하는 둥 선박사고가 빈번히 발생하므로, 이런 소형선박의 사고를 미연에 방지하고, 해난사고 발생시 신속한 조치를 취하기 위하여 어업무선국과 선박간의 지속적인 통신을 유지하는 것이 가장 좋은 방법이라는 것은 두말할 나위가 없을 것이다. 현재, 어업무선국과 소형어선간에 사용하고 있는 27MHz의 SSB(Single Side Band)통신방식으로는 통제가 불가능 할 뿐더러 적절한 시기에 적절한 정보를 제공할 수 없는 게 어업통신의 현실이다. 본 연구에서는 10톤 미만의 소형어선과 어업무선국간의 원활한 통신체제를 구축하여 어민의 생명과 재산을 보호함은 물론 긴급상황 발생시 효과적으로 대처하여 소형어선의 해난사고를 줄이기 위한 통신 체제로서 주파수공용방식(TRS: Trunk Radio System)의 도입을 제안하고 그 활용성을 입증하고자 한다.

• 생물정신의학
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• 제24권4호
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• pp.204-211
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• 2017

Objectives In this study, we identified the symptoms of insomnia, anxiety, and depressed mood in newly diagnosed women breast and thyroid cancer patients. Methods The subjects of this study were 1794 women patients who visited the Ewha Womans University Cancer Center for Women. They included 1119 newly diagnosed primary breast cancer patients and 675 newly diagnosed primary thyroid cancer patients. The patients completed the National Cancer Center Psychological Symptom Inventory (NCC-PSI) during their first follow-up visit after surgery, before starting chemotherapy or radiotherapy. The NCC-PSI is composed of the modified distress thermometer (MDT) and the modified impact thermometer (MIT) for insomnia, anxiety, and depressed mood. Results Anxiety severity was found to be greater in breast cancer patients than in thyroid cancer patients. Significant levels of anxiety, depressed mood and insomnia were present in 28, 24.5, and 20.7% in all the subjects, respectively. Moreover, anxiety symptoms, depressed mood and insomnia interfered with the daily lives of 20, 18.4, and 14.2% of all the subjects, respectively. Dealing with anxiety (18.8%) was found to need the most help, followed by dealing with insomnia (8.9%) and depressed mood (8.7%). Conclusions A significant level of distress was found in about 40% of the total subjects. Nearly 30% of newly diagnosed breast cancer patients reported significant anxiety symptoms and interferences with daily living caused by anxiety, which most commonly needed special care. Early assessment and management of psychological distress, especially anxiety, in breast and thyroid cancer treatment are very important to establish integrated cancer care.

• 한국기계가공학회지
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• 제15권3호
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• pp.130-134
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• 2016

Due to the need for advanced technologies in the automotive industry, the demand for lighter and safer vehicles has increased. Even though various nonferrous metals, like Aluminum, Magnesium and also Carbon Fiber Reinforced Plastic (CFRP), have been implemented in the automotive industry, a lot of technical research and development is still focused on ferrous metals. In particular, the market volume of High Strength Steel (HSS) parts and Ultra High Strength Steel (UHSS) by hot press forming parts has expanded significantly in all countries' automotive industries. A new tool steel, High Thermal-Conductivity Tool Steel (HTCS), for stamping punches and dies has been developed and introduced by Rovalma Company (Spain), and it is able to support better productivity and quality during hot press forming. The HTCS punches and dies could help to reduce cycle time due to their high thermal conductivity, one of the major factors in hot press forming operation. In this study, test dies were manufactured in order to verify the high thermal conductivity of HTCS material compared to SKD6. In addition, thermal deformation was inspected after the heating and cooling process of hot press forming. After heating and cooling, the test dies were measured by a 3D scanner and compared with the original geometry. The results showed that the thermal deformation and distortion were very small even though the cooling time was reduced by 2 seconds.

• 정신신체의학
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• 제25권1호
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• pp.56-62
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• 2017

Objectives : The objective of this study was to investigate the relationship between psychological distress and pain in cancer patients. Methods : 249 patients with cancer who visited National Health Insurance Service Ilsan Hospital between April 2013 and March 2014 were evaluated with National Cancer Center Psychological Symptom Inventory(NCC-PSI) which consisted of Modified Distress Thermometer(MDT) and Modified Impact Thermometer(MIT). Each scale was divided into 3 subscales targeting separate symptoms: insomnia, anxiety, and depression. Psychological distress was defined as positive for those who scored above the cutoff values in at least one of all six subscales. The Numeric Rating Scale for Pain(NRS-Pain) was used to assess the subjective severity of pain. Logistic regression was performed to investigate the association between psychological distress and pain. Results : Univariate logistic regression analysis showed that pain, gender, compliance, and two subscale scores of Hospital Anxiety and Depression Scale(HADS) were significantly associated with psychological distress. Multivariate logistic regression analysis showed that pain and HADS anxiety subscale score maintained a statistically significant association with psychological distress adjusted for variables including age, gender, years of education, Eastern Cooperative Oncology Group performance status, cancer stage, Charlson Comorbidity Index, compliance, and HADS depression subscale score. One point increase in pain was 1.31 times more likely to cause psychological distress. In secondary analysis, pain was significantly associated with all subscales of NCC-PSI, except MIT-anxiety subscale. Conclusions : This study suggests that NCC-PSI, a screening tool for psychological distress, reflects pain. We recommend that physicians who treat cancer patients consider the examination of psychological distress which provides comprehensive evaluation of various factors regarding quality of life.