함정의 형상 반자계 효과가 탈자에 미치는 영향

김영학,Kim, Young-Hak 한국정보통신학회 2016 한국정보통신학회논문지 Vol.20 No.2

본 논문은 함정의 형상이 탈자 이후에 함정에 형성되는 수직자화에 미치는 영향에 대해 조사하였다. 선박의 전면 전개도로부터 함정의 형상을 삼각형, 사각형, 원형으로 선택하여 지자계에 의한 수직방향의 유도자화를 FEM 정자장 해석으로 조사하였다. 탈자과정 중에 자화에 의한 자계를 측정하였으며, 탈자 이후 성분분리를 통해 영구자화에 의한 자계의 수평 및 수직성분의 크기를 바이어스 자계의 변화에 따라 조사하였다. 이 실험으로부터 함정의 형상을 고려하는 탈자처리 방법이 필요하며 방법으로 선수와 선미 쪽에 권선 간격을 좁게 하여 함정의 중앙부분보다 비교적 더 큰 자계가 인가되도록 하는 것이 바람직하다는 것을 알았다. This paper studied on the influence of naval vessel shape on vertical magnetic field after the vessel was demagnetized. The triangular shape, the rectangular shape and circular shape were adaped from vessel's structual drawings. Magneto-static FEM analysis was performed to obtain the iduced magnetic field due to earth magnetic field for those shapes. During demagnetization process, magnetic field of residual magnetization was observed. The holizontal and vertical magnetic field were calculated depending on vertical bias magnetic field through magnetc component seperation. To demagnetize naval vessel ship, demagnetizing coils shoud be wound more finely in the vow and stern of the ship than it should be in the mid-part of the ship.

Flash D 탈자방법에서 수직자화예측을 위한 초기자화율에 관한 검토

김영학,도재원,Kim, Young-Hak,Doh, Jaewon 한국군사과학기술학회 2014 한국군사과학기술학회지 Vol.17 No.5

A permanent vertical magnetization should be obtained to counteract induced vertical magnetization due to the earth's background field during the Flash D demagnetization process. A vertical susceptibility is needed to calculate a extra-permanent magnetization, which is needed to control the permanent vertical magnetization in stage 2 of Flash D demagnetization and added to the final vertical permanent magnetization. Two susceptibilities were found in this paper. One is obtained from the extra-magnetization. The other is obtained by magnetic field measurement from the scaled physical vessel when the vessel is excited by vertical magnetic field. The initial susceptibility by the extra-magnetization was 0.101~0.109 and the one from the measured magnetic field was 0.122. Two susceptibilities have a good agreement each other. From this paper, it is found that the susceptibility is able to appllied to calculate the extr-magnetization.

함정에서 발생하는 자계신호의 성분분리에 대한 검토

김영학,도재원,Kim, Young-Hak,Doh, JaeWon 한국정보통신학회 2014 한국정보통신학회논문지 Vol.18 No.8

함정의 탈자결과 평가를 위한 자계신호의 분리방법에 대한 이론적 근거와 해저 면에 설치되는 사각코일로부터 발생하는 불균일한 자계가 분리결과에 미치는 영향을 측정 신호와 FEM해석을 통해 검토하였다. 측정신호는 제작된 모델함에서 발생하는 자계를 자계센서로 측정한 것이며 FEM 계산은 제작된 모델함과 동일한 형상으로 수행되었다. ILM(induced longitudinal magnetization) 신호와 IVM(induced vertical magnetization) 신호는 함정이 가지는 투자율과 지자계의 수평과 수직방향 성분에 의해 각각 발생하는 자화에 의한 것이며, PLM(permanent longitudinal magnetization) 신호와 PVM(permanent vertical magnetization) 신호는 함정의 영구자화의 수평성분과 수직성분에 의한 것임이 확인되었다. 또한 사각 코일의 수직방향의 자계는 균일한 지자계를 완전히 상쇄할 수 없어 사각코일의 면적에 가까운 크기를 가지는 함정 일수록 사각코일의 자계 불균일성의 영향을 크게 받게 됨을 알았다. This paper investigated the separation of magnetic signal from a ferro-magnetic object. The magnetic signals were ILM(induced longitudinal magnetization) and IVM(induced vertical magnetization), which were induced by earth magnetic field and PLM(permanent longitudinal magnetization) and PVM(permanent vertical magnetization), which were due to a permanent magnetization of the object, respectively. Magnetic signal separation was based on the fact that magnetization vector could be analyzed according to longitudinal and vertical directions. Also the influence of non-uniform magnetic field from a rectangular coil on the separation was examined. A military vessel with a size close to rectangular coil has more errors on the magnetic signal separation.

비히스테리자화에 의한 강관의 탈자 기법 연구

김영학,양창섭,신광호,Kim, Young-Hak,Yang, Chang-Seob,Shin, Kwang-Ho 한국군사과학기술학회 2009 한국군사과학기술학회지 Vol.12 No.1

In this study, we investigated whether the anhysteretic demagnetization process would be applicable to remove a complicated magnetization of a steel tube as a part of the experimental earlier study for a deperming of naval vessel. The magnetic tube used in this study was a 10cm-long and 1cm-diameter steel tube, and magnetized with a E-shape ferrite core to form a nonuniform magnetization in it. In the anhysteretic demagnetization process, a dc magnetic field applied along the longitudinal direction of the tube decreased from ${\pm}$3kA/m to zero-field with the step of ${\pm}$300A/m. At the same time, an ac bias magnetic field with the frequency of 60Hz and the field intensity of 300A/m was excited along the circumstantial direction of the tube. It was found that the anhysteretic process was useful to demagnetize a small-object like a steel tube from the experimental results showing the residual magnetization reduced over 90%.

재구성 가능한 메쉬에서 결정적 유한 자동장치 문제에 대한 상수시간 알고리즘

김영학(Young Hak Kim) 한국정보처리학회 1999 정보처리학회논문지 Vol.6 No.11

In this paper, we propose the mod%uB514 %uC0C8 measure and compare the performances of the Linux, PC_Solaris and FreeBSD which are the heterogeneous PC based UNIX kernels connected by network. Using the stop-watch timer with the %u33B2 unit, we measure the important performance indices of UNIX kernels which are the primitive and command execution time and disk I/O time. Also we measure the message transfer time using the TCP, UDP and RPC methods to compare the network performance of UNIX kernels. And we compare the performance of NFS for each UNIX kernels. And we display the measured data on internet.

지목별 토양오염관리 실태에 관한 연구

김영학(Kim Young-Hak) 한국지적정보학회 2001 한국지적정보학회지 Vol.3 No.-

본 연구의 목적은 지목별 토양오염관리의 현황 및 문제점을 분석하여 미래 지향적이고 효율적인 지목관리에 일조하는 것이다. 이러한 목적을 달성하기 위하여 토양측정망 중 전국망인 토지용도별 토양오염관리를 연구대상으로 설정하고 지역망은 연구진행의 이해를 돕는 차원에서 간략히 언급하게 된다. 전국망의 구성요소는 거시적으로 지목, 오염물질, 측정지점, 측정망운영ㆍ관리, 토양오염방지 조치 및 대책 등으로 구성되고 이들을 토대로 현황 및 문제점을 검토하여 이에 대한 개선방향을 모색하게 된다. 또한 지목별 토양오염관리의 실태를 파악하기 위한 분석기준으로는 지목선정의 합리성, 측정지점의 대표성, 운영관리의 효율성, 방지대책의 미래지향성 등을 설정하여 연구를 진행하게 된다. The purpose of this study is to contribute the efficient and future-oriented management of land category by grasping and analyzing control conditions and problems of soil pollution by land category. As the subject of study that can achieve this purpose, we chose the Control of Soil Pollution by Land category (National Network) out of Soil Measuring Network. On the other hand, local area network chose beside the point. The factors composing National Network are land category, pollutant, measuring point, operation and maintenance of soil measure network, and check disposal and counterplan of soil pollution. We would provide the progress solutions by examining the actual conditions and problems of its. Moreover, the criteria on analysis that grasp the Control conditions of Soil Pollution by Land category includes the rationality of land category selection, the representation of measuring point, the efficiency of operation and maintenance, and the future-oriented tendency of check disposal and counterplan.

지속 가능한 발전을 위한 지적행정의 역할

김영학(Kim Young Hak) 한국지적정보학회 2002 한국지적정보학회지 Vol.4 No.-

본 연구의 목적은 지속가능성과 지적행정과의 관계설정을 통하여 지속가능한 발전을 위한 지적행정의 지원체계를 검토하고 이를 토대로 지속가능성을 위한 지적행정의 역할과제를 제시하는 것이다. 이러한 목적을 달성하기 위하여 지적행정의 지원체계를 법ㆍ제도적 지원, 경제ㆍ사회적 지원, 기술적 관리지원 등으로 구분하여 검토하였고, 이를 기반으로 지속가능성의 합리적인 의사결정을 지원하기 위하여 지적행정이 해결해야 할 역할과제를 제시하였다. The purpose of this study is to provide an alternative that reinforce the role of cadastral administration in achieving sustainability by examining the supportable systems of cadastral administration and the relationship of sustainability to cadastral administration. As the supportable systems of cadastral administration that can achieve this purpose, we operate the legal and institutional, an economic and social, and the technical supporting aspects. On the basis of its aspects, operating of cadastral administration for sustainable development is examined. The results provide some important problems for cadastral administration to solve.

[SAFETY 부문] Monte Carlo 방법을 이용한 충돌 판별 알고리즘의 신뢰성 검증

김영학(Young-Hak Kim),정현용(Hyun-Yong Jeong) 한국자동차공학회 2000 한국자동차공학회 춘 추계 학술대회 논문집 Vol.- No.-

The Monte Carlo method was used to evaluate the reliability of crash discrimination algorithms. Through the Fast Fourier Transformation, crash pulses obtained during frontal crash tests of a mini van and a sports utility vehicle were transformed to the frequency domain, and basic signals and changeable signals were determined. By modifying the changeable signals through random generation and combining the modified signals and the basic signals, numerous crash pulses Could be generated For the generated pulses, crash discrimination algorithms were evaluated by examining whether they resulted in time-to-fires faster than required time-to-fires for the pulses requiring air bag deployment and whether they did not result in air bag deployment for the pulses requiring no air bag deployment The crash discrimination algorithm in which the summation of the absolute value of the deceleration change or the absolute value of the deceleration change multiplied by velocity was used as a metric was proven to be highly reliable.

사설 검도장의 효율적인 운영방안 연구

김영학(Kim, Young-Hak),허건식(Heo, Keon-Sik),강길훈(Kang, Gil-Hun) 용인대학교 무도연구소 1996 武道硏究所誌 Vol.7 No.1

초등학생의 검도대회 참가경험, 자기효능감 및 지속참여의 관계

김영학(Kim, Young-hak),김형룡(Kim, Hyung-Ryong) 대한검도학회 2022 대한검도학회지 Vol.33 No.1

이 연구는 초등학생의 검도대회 참가경험, 자기효능감 및 지속참여의 관계를 규명하여 검도수련 저변확대에 기여할 수 있는 기초자료를 제공하는데 목적을 두고 연구를 진행하였다. 이를 위해 2022년 5월에서 9월사이 진행된 초등학생 검도대회 및 검도대회 초등부에 참여한 초등생 260명을 대상으로 설문조사를 실시하였으며, 이 중 232부를 최종분석에 활용하였다. 그 결과 첫째, 초등학생의 검도대회 참가경험은 자기효능감에 정적영향을 미치는 것으로 나타났다. 둘째, 초등학생의 검도대회 참가경험은 지속참여에 정적영향을 미치는 것으로 나타났다. 셋째, 초등학생의 검도에 대한 자기효능감은 지속참여에 정적영향을 미치는 것으로 나타났다. 지속적인 검도참여와 저변확대를 위해서는 어린학생들의 지속적인 참여가 필요하며 이들의 지속적인 참여를 이루기 위해서는 수련의 결과를 확인할 수 있는 대회 참여를 통해 성취감을 얻는 것이 효과적임을 확인할 수 있었다. This study was conducted with the aim of providing basic data that can contribute to the expansion of the base of kendo training by investigating the relationship between elementary school student participation experience, self-efficacy, and continuous participation. To this end, a survey was conducted on 260 elementary school students who participated in the elementary school kendo competition and kendo competition held between May and September 202 of them were used for the final analysis. As a result, first, it was found that elementary school students’ experience of participating in kendo competitions had a positive effect on self-efficacy. Second, it was found that elementary school students’ experience of participating in kendo competitions had a positive effect on continuous participation. Third, it was found that elementary school students’ self-efficacy for kendo had a positive effect on continuous participation. Continuous participation of young students is required to continuously participate in kendo and expand the base, and in order to achieve continuous participation, it was confirmed that it was effective to gain a sense of achievement through participation in competitions that could confirm the results of training.