• 한국항공우주학회지
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• 제38권8호
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• pp.747-757
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• 2010

날개위에 쌓인 얼음은 날개의 공기역학적 성능을 저하시키고 항공기 사고를 야기하는 주요한 원인이 된다. 결빙된 날개의 형상 예측 연구는 얼음으로 변형된 날개의 공기역학적 성능 파악과 제빙 방빙 장치 설계에 선행 되어야 한다. 이를 위해 본 연구에서는 2차원 익형에 발생하는 유리얼음 형상을 예측할 수 있는 코드를 개발하였다. 계산의 효율성을 위해 익형 주위의 유동장 계산은 정상 용출 및 중첩 패널기법을 사용하였고 날개표면과 날개에 유입된 물의 열전달은 Messinger 모델을 통해 고려하였다. 본 코드의 해석 결과는 실험 및 LEWICE 등 기존 해석 프로그램과 상호 검증되었다. 결빙형상의 주요한 요소인 얼음 뿔의 진행 방향 및 얼음 두께는 실험 및 타 프로그램과 유사한 결과를 나타내었다. 또한 대기온도, 수증기 함량, 입자 반지름, 자유류 등이 착빙 형상에 미치는 영향을 체계적으로 분석하였다.

• 대한임상독성학회지
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• 제4권1호
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• pp.32-43
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• 2006

Purpose: Toxic Exposure Surveillance System (TESS) is widely used for poisoning data collection and making a counterplan. But, there were few reports about poisoning data collection using TESS in Korea. The aim was to collect poisoning data using TESS report form and investigate the recognition of emergency physician about the necessity of TESS as preliminary survey. Methods: Retrospectively, we gathered data from hospital records about the patient who admitted hospital emergency room due to poisoning. Date were gathered by paper and/or web client system report form in patients recruited by ICD-10 codes Results: From Jun 2004 to May 2005,3,203 patients were enrolled in 30 hospitals and their mean age was $44.9{\pm}20.3years$ old(male: female = 1,565: 1,638). The most frequent site of exposure was their own residence (73.2%, 2,345/3,203) and most of reported patients were older than 20 years(89.7%, 2,871/3,203). Frequent substances involved in poisoning were medication(41.9%) and pesticide(33.3%). Intentional poisoning was 60.7%(1,954). In fatality, overall frequency was 5.1%(162/3,203) and the most frequent route of exposure was ingestion(96.3%, 156/162) and the most frequent substance was pesticide(85.2%, 138/ 162). Antidotes were administered in 202 patients(2-PAM, atropine, antivenin, N-acetylcystein, vitamin K, flumazenil, ethanol, methylene blue, naloxone, calcium compound). 19 of 20 emergency physicians agreed with necessity of TESS. Conclusion: Data collection using TESS report form showed preliminary poisoning events in Korea. Frequent poisoning substance were medication and pesticide. The fatality was mainly related with pesticide ingestion. Many doctors in emergency room recognized the necessity of TESS.

• 한국통신학회논문지
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• 제31권11A호
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• pp.1092-1100
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• 2006

본 논문에서는 4개의 송신 안테나에서 full rate를 달성할 수 있는 준직교 QOSTF-OFDM(quasi-orthogonal space-time-frequency block coded orthogonal frequency division multiplexing)기법을 제안한다. 제안된 방식은 full rate를 달성할 수 있지만 full diversity를 달성할 수 없기 때문에 수신기에서 diversity손실을 보상하기 위해 DAC-ZF(diversity advantage collection with zero forcing)수신 기법을 사용한다. 동일한 주파수 효율을 가진다는 가정하에서 제안된 방식은 full rate을 달성할 수 없는 다른 선형 직교 시공간 기법과 비교할 때 full rate를 달성할 수 있기 때문에 저 레벨(low level) 변조 기법을 적용함으로써 변조 이득(modulation advantage)을 얻을 수 있다. 모의 실험 결과 제안된 방식은 변조 이득과 collected 다이버시티 이득으로 인해 다른 직교 방식과 비교하여 더 높 BER성능을 얻을 수 있다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.277-277
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• 2022

Lignin modification has been a breeding target for the improvements of forage digestibility and fermentation in whole crop silage(WCS) rice. In rice, gold hull and internode 2 (gh2) was identified as a lignin-deficient mutant. gh2 exhibits a reddish-brown pigmentation in the hull and the internode is located on the short arm of chromosome 2 and codes for cinnamyl-alcohol dehydrogenase (CAD). To develop WCS rice variety improved digestibility and fermentation, we measured acid detergent fiber (ADF), lignin and total digestible nutrient (TDN) calculated from ADF (TDN=88.9-(0.79% × ADF) and performed marker-assisted selection using CAD(Os2g0187800) gene first intron region specific marker with 55 Jungmo1038/J.collection lines. Those lines had lignin content range from 0.82 to 6.61%, ADF from 15.8 to 45.8%, TDN from 52.7 to 78.8 compared to 'Jungmo1038'(1.53,20.7,72.6), 'J.collection'(0.98,12.8,78.8%) and gh2 were introgressed into 44 lines. Considering on these genotype and low-lignin phenotype, we finally selected 2 elite lines(Suweon668, Suweon669). Suweon668 and Suweon669 line are high biomass-low lignin lines that the ADF content is relatively low, even though the dry matter weight is high. Also they have lodging and shattering resistance and glabrous leaf and hull important to improve cattle palatability. Our results will provide that rice can be improved for forage digestibility and fermentation with low lignin concentration.

• 한국전통조경학회지
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• 제39권1호
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• pp.31-36
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• 2021

본 연구는 조선시대 법전류에 기록된 산림 관련 자료를 수집하고 분석을 통하여 그 당시 산림문화의 전반적인 사항을 파악 후 국민의 산림문화 충족 욕구에 부응하고자 수행하였다. 조선시대 법전류(경국대전, 속대전, 대전통편, 대전회통)에 기록된 산림 관련 조항을 통해 산림행정과 정책의 변화과정 및 산림의 경관상 변화를 고찰할 수 있었다. 경국대전(經國大典)의 분석을 통해 특수한 수종이나 특정 지역에만 생산되는 수종에 대한 관리와 특정 지역 경관 관리에 신경을 많이 기울였다는 것, 금산 관리 규정에 있어서 벌채를 금하는 수준을 넘어 재식과 배양뿐만 아니라 경관 조성에도 관심을 기울였다는 것을 알 수 있었다. 또한, 일반적으로 산림의 사유를 금했었으나. 상·장례에 있어서 분묘 주변의 일정 범위의 산림에 대한 소유를 인정하고 있음을 확인하였다.

• 컴퓨터교육학회논문지
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• 제9권4호
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• pp.55-61
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• 2006

PSP(personal software process)는 소프트웨어 개발자들이 양질의 코드를 생산할 수 있도록 개발된 정밀하면서도 계량적인 수치를 기반으로 한 소프트웨어공학 기법이다. PSP의 효과적 학습을 위해서는 프로젝트에서 발생하는 많은 양의 데이터를 계산하고 기록하는 작업을 필수적으로 행해야만 한다. 이 작업은 많은 시간이 소요될 뿐 아니라, 오류의 발생이 쉬워 PSP 학습의 동기와 효과를 감소시키는 결과를 초래한다. 이를 개선하기 위해서 본 연구에서는 데이터의 정리, 검증 및 분석을 처리할 수 있도록 웹 기반의 PSP 로그 시스템을 설계하고 구현하였다. 3년간의 실험 결과는 이 시스템이 생산성과 정밀도를 높일 뿐만 아니라, 데이터의 처리보다는 PSP 기법의 프로세스에 대한 학습과 교수에 더 집중할 수 있게 해주었음을 보여주었다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권6호
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• pp.2881-2894
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• 2018

Cyber attacks are increasing continuously. On average about one million malicious codes appear every day, and attacks are expanding gradually to IT convergence services (e.g. vehicles and television) and social infrastructure (nuclear energy, power, water, etc.), as well as cyberspace. Analysis of large-scale cyber incidents has revealed that most attacks are started by PCs infected with malicious code. This paper proposes a method of detecting an attack IP automatically by analyzing the characteristics of the e-mail transfer path, which cannot be manipulated by the attacker. In particular, we developed a system based on the proposed model, and operated it for more than four months, and then detected 1,750,000 attack IPs by analyzing 22,570,000 spam e-mails in a commercial environment. A detected attack IP can be used to remove spam e-mails by linking it with the cyber removal system, or to block spam e-mails by linking it with the RBL(Real-time Blocking List) system. In addition, the developed system is expected to play a positive role in preventing cyber attacks, as it can detect a large number of attack IPs when linked with the portal site.

• 한국간호교육학회지
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• 제15권2호
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• pp.183-193
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• 2009

Purpose: The purpose of this study was to explore experiences among undergraduate nursing students in a high-fidelity simulation education course for a semester. Method: The participants in this study were 10 nursing students in the senior classes and volunteers. Data collection was conducted using a focus group interview for 100 minutes, which was recorded on video tape. Transcribed data was analyzed through qualitative content analysis. Result: The results of this study were deduced as 4 codes and 22 themes. Study participants reported experiences due to the simulation method itself, interaction among peer group and personal experiences during high-fidelity simulation education. Additionally, experiences related to clinical application were examined. The participants indicated positive outcomes such as developing clinical judgment skills and confidence. Conclusion: Overall, the results of this study supported the usability and effectiveness of a high-fidelity simulation education method in undergraduate nursing curriculum. Further studies are needed to provide more reliable and valid educational information.

• 한국멀티미디어학회논문지
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• 제18권12호
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• pp.1501-1508
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• 2015

In this paper, we describe a case study to improve performance through the load testing of multi-tired system for financial accounts before the system opening. The load test was conducted after the data collection tools(Performance Monitor, DB PSSDiag) were installed. By analyzing the collected log, we were able to identify the main sector requiring performance improvements among the presentation tier, web tier, business logic tier and data tier. The ASP.NET server-down on the web tier could be improved by modifying the parameter values in the configuration file. Some server downs occurred on the business logic tier when a large number of users access at the same time, were more difficult to be solved. By analyzing the hang-dump at the server-down time, we were able to find a process that caused the problem. and we had to modify the relevant codes. For major performance improvements of the data-tier, indices of some queries was optimized by using the built-in DBMS query analyzer, after analyzing the log of long-response-time queries. The problems and solutions considered in this case study will be a reference for the performance improvement of a multi-layer system with the similar structure.

• 한국항해학회지
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• 제6권2호
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• pp.13-33
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• 1982

The NAVSTAR/GPS is a satellite-based navigation system that will provide extremely accurate three-dimensional position and velocity information to users anywhere on or near the earth. This system has been studied primarly for military use and thus the results of studies are seldom obtainable for civilian use up to date. Expecting this system to be opened to civilian use in the future, this paper aims to the collection of basic data of the PN phase modulated communication system adopted in the GPS system by computer simulation. The results of studies are as follows; 1) The PN phase modulation of the speed of 106b/s can be simulated by Fourier summation, the spectrum region which can be restricted is in the region of 0.5-1.5 MHz and spectrum number required is over than 270. 2) By computer simulation, it is verified that optimum r.f filter bandwidth is about 0.3 MHz for the case of $10^6$b/s PN codes phase modulated in 1.575GHz carrier. 3) In case that PN rate to data rate is between 10 and 100, the allowable minimum SNR to demodulate data signal correctly by optimum LPF is about 0.3. It is also verified that the larger the frequency ratio of PN code to the data code, the lower the allowable minimum SNR required.