• 정보처리학회논문지B
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• 제17B권2호
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• pp.157-162
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• 2010

본 논문에서는 분산된 거대한 네트워크상의 데이터에서 유용한 정보를 추출하는 새로운 마이그레이션 조절방법을 이용한 유전 알고리즘을 제안한다. 제안된 알고리즘의 주된 아이디어는 부분 개체군 사이에서 개체들의 이동에 필요한 파라미터들을 적응적으로 결정하는 것이다. 또 이동된 개체들이 새로운 부분 개체군에서 도태되지 않고 적응 할 수 있기 위한 방법을 제시한다. UCI 기계학습 관련 데이터 셋에서 중앙 집중적 단일 유전 알고리즘과 제안된 알고리즘을 비교하기 위해 여섯 개의 데이터를 사용했다. 결론적으로 분산 유전 알고리즘을 적용한 특징 부분 집합이 단일 유전 알고리즘을 적용한 것 보다 좋은 성능을 보였다.

• 정보보호학회논문지
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• 제31권5호
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• pp.901-909
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• 2021

모바일 기기는 그 자체가 가지고 있는 연산 자원이 제한적이기 때문에 클라우드를 활용하여 컴퓨팅하거나 데이터를 저장하는 경향이 있다. 5G로 인해 실시간성이 중요해 짐에 따라, 중앙 클라우드보다 사용자에게 더 가까운 위치에서 컴퓨팅하는 엣지 클라우드에 관한 많은 연구가 수행되었다. 사용자가 현재 연결된 기지국의 엣지 클라우드와 물리적인 거리가 멀어질수록 네트워크 전송 속도가 느려지게 된다. 따라서 원활한 서비스 이용을 위해서는 가까운 엣지 클라우드로 애플리케이션을 마이그레이션 한 뒤 재실행해야 한다. 우리는 호스트 운영 체제와 독립적이며, 가상 머신에 비해 이미지 크기가 상대적으로 가벼운 도커 컨테이너에서 애플리케이션을 실행한다. 기존의 마이그레이션 연구는 네트워크 시뮬레이터를 사용하여 실험하였다. 시뮬레이터는 고정된 값을 사용하기 때문에 실제 환경에서의 결괏값과는 차이점이 발생한다. 또한, 공유 저장소를 통해 이미지를 마이그레이션 하는 방식을 사용하였는데, 이는 패킷 내용 노출에 대한 위험을 갖는다. 본 논문에서는 실제 환경에서 엣지 컴퓨팅 환경을 구현하여 데이터 암호화 전송방식인 안전 복사(Secure CoPy) 방식으로 컨테이너를 마이그레이션 한다. 공유 저장소 방식 중 하나인 네트워크 파일 시스템(Network File System)과 마이그레이션 시간을 비교하고 안전성 확인을 위해 네트워크 패킷을 분석한다.

• 한국표면공학회지
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• 제29권6호
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• pp.753-759
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• 1996

The artificial construction of well-defined low-dimensional (low-D) quantum structures, such as quantum wire (QWR) still attracts attention of many researchers due to their applications in room-temperature optoelectronic devices. In this work, the migration enhanced epitaxial growth (MEE) and the analysis of InAs/ AlAs QWR are reported. On the vicinal semi-insulating InP substrate of $3^o$ tilted cut from (100) surface towards (010) direction, InAs/ AlAs QWR superlattices have been successfully grown by MEE with the introduction of growth interruption at each shutter operation of MBE cell. The in-situ RHEED analyses show that MEE gives superior step-flow growth (SFG) and sharper interface formation over a conventional MBE growth. We have grown 4 samples in series varying the growth temperature. The QWR samples are analyzed by photoluminescence (PL) and atomic force microscopy (AFM). From the AFM images, we can get the definitely resolved 1-D structures. This structure is believed to be due to the MEE method and its separation is better than any other data from others. We are now studying the dependence of the structure on the growth temperature.

• 지역사회간호학회지
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• 제16권1호
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• pp.86-94
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• 2005

Purpose: This study investigated the Korean nurses' international migration to provide the basic data for establishing plans of supply and demand for nurses and the status of Korean nurses' application for foreign nurse licenses and overseas employment. Method: The subjects were 5.447 nurses who requested English written nurse license to the Ministry of Health and Welfare for the application of foreign nurse license examinations and overseas employment. Human Resources Development of Korea provided documents of nurses migrated to Saudi Arabia. Data were collected from December, 2002 to July, 2003 and analyzed by using descriptive statistics. Result: The total applicants for foreign nurse license were 3,149 for 2 years. In the year 2001, 1.129 nurses applied, 2,020 nurses in the year 2002. Out of 3,149 total subjects, 2,705(85.9%)nurses applied for U. S. A. nurse license. Eighty percent of the applicants of the U. S. A. nurse license examination applied for the New York states. The number of applicants for Canada was 215(6.8%), followed by Australia 88(2.8%), U. K. 86(2.7%), and New Zealand 45(1.4%). Average age of the applicants was 31, 49.0% of them were in their twenties. Three year college graduates accounted for 64.1% B.S.N. 33.9%. Applicants graduated from universities or colleges of Seoul area were 37.3%, followed by Daegu. The total number of nurses employed overseas were 1,291 during 2001 and 2002. Seven hundred thirty eight nurses(57.2%) were employed in the U. S. A.. Average age was 34, 60.9% were 3year college graduates, nurses graduated from Seoul area were 44.9%. No one applied for Saudi Arabian nurse license, 172 nurses were employed during 1999 and 2002, 39.5% of them were in their thirties. Conclusion: The results of this study shows relatively young and experienced nurses have intention to migrate internationally and they actually migrate to other countries. Comparing the number of nurses migrating to other country with the number of newly issued nurse licenses in Korea every year. the percentage of overseas employment was relatively high. To cope with Korean nurses international migration. new policy to monitor the status of nurse's international migration and an institution to deal with the affairs should be established. And the further study is needed to measure nurse's competence and influencing factors of Korean nurses employed in the U. S. A.

• 농촌계획
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• 제12권3호
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• pp.39-42
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• 2006

The purpose of this study is to develop rural population model adapting cohort survival method with sift-share effects. Administrative district in this study is below Myun: about 2,000 population. Population data of rural area in 1990, 1995, and 2000 by age cohort were selected for applying developed model. Damping coefficient from population data was calculated as 7% and results applying this coefficient in rural population data below the error from 12% to 1.06%. In detail, most of cohorts fitted with developed model except from 15 to 29 age groups. Application result of small population area; DaesulMyun revealed that main factor of population change is not natural change but migration.

• 디지털융복합연구
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• 제12권10호
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• pp.271-282
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• 2014

최근 클라우드 컴퓨팅이라는 패러다임의 기술과 개념은 사실상 거대한 자원의 활용과 다양한 서비스를 시간과 장소의 구애 없이 효율적인 비용으로 제공된다는 장점으로 기업들의 도입이 점차 늘어가고 있다. 하지만, 보안, 호환성, 통제력 상실, 보안, 데이터보호, 성능과 업타임, 클라우드 컴퓨팅 서비스의 벤더 종속에 대한 위험성, 기존 시스템과 호환성, 이식성에 대한 불안으로 국내에 클라우드 도입은 아직 미미한 상태이다. 특히 기존 시스템의 이전에 관심과 이슈는 높지만, 그에 따른 연구가 아직은 부족한 상황이다. 본 논문에서는 클라우드 도입사례와 클라우드 컴퓨팅 환경으로의 기존 시스템 이전에 관련한 방법론과 방안에 대해 연구하고 한계점을 도출하고 클라우드 컴퓨팅을 위한 기존 시스템의 현대화에 대해 방안을 제시하였다.

• 한국BIM학회 논문집
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• 제12권4호
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• pp.52-60
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• 2022

Recently, the demand for connection between various heterogeneous dataset and BIM as a construction data model hub is increasing. In the past, in order to connect model between BIM and heterogeneous dataset, related dataset was stored in the RDBMS, and the service was provided by programming a method to link with the BIM object. This approach causes problems such as the need to modify the database schema and business logic, and the migration of existing data when requirements change. This problem adversely affects the scalability, reusability, and maintainability of model information. This study proposes an ontology BIM-based knowledge service framework considering the connectivity and scalability between BIM and heterogeneous dataset. Through the proposed framework, ontology BIM mapping, semantic information query method for linking between knowledge-expressing dataset and BIM are presented. In addition, to identify the effectiveness of the proposed method, the prototype is developed. Also, the effectiveness and considerations of the ontology BIM-based knowledge service framework are derived.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 2003년도 Proceedings of the international symposium on the fusion technology
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• pp.441-448
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• 2003

Refraction tomography requires an algorithm for efficiently computing the traveltimes and their $Fr\'{e}chet$ derivatives. We have attempted to solve the damped wave field using the frequency domain finite element model ing and then invoked the reciprocity theorem to calculate the $Fr\'{e}chet$ derivative of the traveltime with respect to the subsurface parameter. Then, we used a damped least square method to invert the traveltimes of the Marmousi 2 model. Numerical tests demonstrate that the refraction tomography with large aperture data can be used to estimate the smooth velocity model for the prestack depth migration.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.638-642
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• 2005

For gas hydrate exploration, long offset multichannel seismic data acquired using by the 4km streamer length in Ulleung basin of the East Sea. The dataset was processed to define the BSRs (Bottom Simulating Reflectors) and to estimate the amount of gas hydrates. Confirmation of the presence of Bottom Simulating reflectors (BSR) and investigation of its physical properties from seismic section are important for gas hydrate detection. Specially, faster interval velocity overlying slower interval velocity indicates the likely presences of gas hydrate above BSR and free gas underneath BSR. In consequence, estimation of correct interval velocities and analysis of their spatial variations are critical processes for gas hydrate detection using seismic reflection data. Using Dix's equation, Root Mean Square (RMS) velocities can be converted into interval velocities. However, it is not a proper way to investigate interval velocities above and below BSR considering the fact that RMS velocities have poor resolution and correctness and the assumption that interval velocities increase along the depth. Therefore, we incorporated Migration Velocity Analysis (MVA) software produced by Landmark CO. to estimate correct interval velocities in detail. MVA is a process to yield velocities of sediments between layers using Common Mid Point (CMP) gathered seismic data. The CMP gathered data for MVA should be produced after basic processing steps to enhance the signal to noise ratio of the first reflections. Prestack depth migrated section is produced using interval velocities and interval velocities are key parameters governing qualities of prestack depth migration section. Correctness of interval velocities can be examined by the presence of Residual Move Out (RMO) on CMP gathered data. If there is no RMO, peaks of primary reflection events are flat in horizontal direction for all offsets of Common Reflection Point (CRP) gathers and it proves that prestack depth migration is done with correct velocity field. Used method in this study, Tomographic inversion needs two initial input data. One is the dataset obtained from the results of preprocessing by removing multiples and noise and stacked partially. The other is the depth domain velocity model build by smoothing and editing the interval velocity converted from RMS velocity. After the three times iteration of tomography inversion, Optimum interval velocity field can be fixed. The conclusion of this study as follow, the final Interval velocity around the BSR decreased to 1400 m/s from 2500 m/s abruptly. BSR is showed about 200m depth under the seabottom

• 한국정보통신학회논문지
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• 제9권4호
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• pp.877-882
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• 2005

과학적 응용에서 발생하는 각종 실험 데이터의 관리에 대한 관심이 높아지고 있으나 체계적인 관리 방법에 대한 연구가 많지 않다. 이 논문에서는 과학적 응용에서 발생하는 군집을 이루는 시간 데이터를 관리하는 방법을 제안한다. 먼저, 시간 데이터를 구분하는 경계값 LB와 RB를 정의하고 과거, 현재, 미래 세그먼트에 각각 저장되는 개체 버전을 정의하였다. 또한 Hotspot 분포를 가지는 시간 데이터에 대하여 각 세그먼트 사이에 이동하는 알고리즘을 나타내었고, 제안하는 최소중복을 이용한 이동 방법과 기존방법에 대하여 성능을 비교하였다. 질의에 대한 평균 응답 시간에서는 기존의 방법과 비슷한 결과를 보였다. 제안한 이동 방법은 세그먼트 사이에 중복해서 저장되는 데이터 수를 적게 하므로 공간 이용율 측면에서는 기존의 이동 방법보다 효율적이었다.