• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.5
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• pp.566-571
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• 1988

Laser scanning system using a hologram is simpler in optical system, lower in cost than using a polygon. In this paper, a thick hologram is fabricated for the underfilled transmission disk type with a merit of wabble insensitivity to vibration. High diffraction efficiency over 50% is obtained using silver halide recording material. The two-dimensional scan pattern with 13 scan-line is made by 7-facet hologon and mirror system. This system can be practically applied to POS(Point of Sale) bar-code symbol reader.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.3
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• pp.19-26
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• 1999

The detectability of pipes buried in dry sand is investigated by using the GPR with self-designed bow-tie antenna. The antennas are covered with shielding structures to reduce the direct-coupling between the transmitting and receiving antennas. The ringing, due to finite length of the antenna, is decreased by performing resistive termination at the ends of the antennas. It is shown that without additional signal processing, the presence of various buried targets can be found by discriminating hyperbolic pattern in B-scan data.

• Korean Journal of Human Ecology
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• v.23 no.5
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• pp.891-904
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• 2014

The objective of this study is to classify somatotypes of back-surface shape of women in their late 20s by using 3D body scan data(Size Korea 2010) in order to improve fitness of Hanbok Jeogori. The results were as follows: 1. According to the in-depth survey of the experienced expert's interview, most problems related to the fit were caused by the back area of Jeogori. 2. The result of factor analysis indicated that 6 factors were extracted and those factors comprised 82.85% of total variance. 3. According to the cluster analysis, back somatotypes of women in their late 20s were categorized by two types : straight type(54.1%) and bending type(46.9%). The results could be used as the Hanbok Jeogori to improve the fitness of back-surface shape.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.91-94
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• 2003

Laminated composites are liable to fatal damage under impact load due to the fact that they have no reinforcement in the thickness direction. To overcome the inherent weakness, three dimensional (3D) textile reinforcements have drawn much interests. In this paper, impact performance of 2D and 3D textile composites has been characterized. For 2D composites, fiber bundle size and fiber pattern have been varied. For 3D composites, orthogonal woven preforms of different density and type of through-thickness fibers have been studied. To assess the damage after the impact loading, specimens were subjected to C-scan nondestuctive inspection. Compression after impact (CAI) were also conducted in order to evaluate residual compressive strength.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10c
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• pp.662-664
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• 1998

IEEE 1149.1 바운다리스캔은 보드 수준에서 고장점검 및 진단을 위한 테스트 설계기술이다. 그러나, 바운다리스캔 제어기의 특성상 테스트 패턴의 주입에서 관측까지 2.5 TCK가 소요되므로, 연결선상의 지연고장을 점검할 수 없다. 본 논문에서는 Update_DR 신호를 변경하여, 테스트 패턴 주입에서 관측까지 1 TCK가 소요되게 함으로써, 지연고장 점검을 가능하게 하는 기술을 소개한다. 나아가서, 정적인 고장점검을 위한 테스트 패턴을 개선해 지연고장 점검까지 가능하게 하는, N개의 net에 대한 2log(N+2)의 새로운 테스트패턴도 제안한다. 설계와 시뮬레이션을 통해 지연고장 점검이 가능함을 확인하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.1
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• pp.77-83
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• 2002

Recently, the industrial development caused the expansion of city and the field of construction is being larged in size. So, information of construction buried in underground is necessary. In this paper, we were investigated the detachability on various specimen in self-designed test field using the GPR system with three antenna elements and it was constantly radiated 730 MHz frequency. To examine the detachability on various condition, the test were displayed B-scan CRT. And the pattern was exactly positioned when it was compared to the real buried-depth. Therefore, we can confirm similarity between the wave-propagation velocity and previous results.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.707-714
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• 2010

Since an LFSR(linear feedback shift register) as a pattern generator has solely linear dependency in itself, it generates sequences by moving the bit positions for pattern generation. So the correlation between the generated patterns is high and thus reduces the possibility of fault detection. To overcome these problems many researchers studied to have goodness of randomness between the output test patterns. In this paper, we propose the new and effective method to construct phase shifter as PRPG(pseudo random pattern generator).

• Journal of the Ergonomics Society of Korea
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• v.21 no.3
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• pp.59-79
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• 2002

The purposes of the study were to present the optimum slacks pattern for elementary school girls and to compare and evaluate wearing ease of the slacks. 3D scans using the Cyberware PS motion platform were carried out for 3 subjects who have different body type. The automatic drafting method was programmed by AutoLISP in CAD. Wearing tests using 3D Scanner was done for evaluation of fitness of slacks. Regression analysis, analysis of variance and post-hoc test were performed for statistical analysis of the data by SPSS program. The procedure and results were as follows: The slacks construction components for pattern drafting were derived from 10 horizontal section maps obtained from 3D scans. The automatic drafting was based on the measurements of slacks construction components and the curve of crotch line. The crotch line was drafted using of the arc function in AutoCAD. The total crotch length was calculated using the multiple regression equation. Wearing test represented that the slacks pattern developed to accomodate individual body measurements was estimated more highly than existing patterns.

• The Journal of Korean Obstetrics and Gynecology
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• v.21 no.3
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• pp.231-244
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• 2008

Purpose: The purpose of this study is to analyze body composition, obesity according to working pattern of working women. The subjects were workers in the automobile manufacturing industry. Methods: The subjects consisted of 514 industrial women workers who had received Korean oriental medicine health examination and submitted questionires about working pattern, during 8 months from April 2005 to November 2005. The body composition was measured by X-scan(Jawon medical, Seoul, Korea). We analyzed the relationship between body composition analysis, obesity and shift pattern with $X^2-test$ using the SPSS Ver. 12.0 Results: Regarding the realationship between body composition and working pattern, shift worker group had a significantly higher level of body weight, ratio of body fat, visceral fat and abdominal fat than normal worker. Conclusion: From this study, we can know that shift work can influence on working women's body composition and obesity.

• Investigative Magnetic Resonance Imaging
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• v.11 no.2
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• pp.95-102
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• 2007

Purpose: To acquire high-resolution spiral-scan images at higher magnetic field, high homogeneous magnetic field is needed. Field inhomogeneity mapping and in-vivo shimming are important for rapid imaging such as spiral-scan imaging. The rapid scanning sequences are very susceptible to inhomogeneity. In this paper, we proposed a higher-order shimming method to obtain homogeneous magnetic field. Materials and Methods: To reduce measurement time for field inhomogeneity mapping, simultaneous axial/ sagittal, and coronal acquisitions are done using multi-slice based Fast Spin echo sequence. Acquired field inhomogeneity map is analyzed using the spherical harmonic functions, and shim currents are obtained by the multiplication of the pseudo-inverse of the field pattern with the inhomogeneity map. Results: Since the field inhomogeneity is increasing in proportion to the magnetic field, higher order shimming to reduce the inhomogeneity becomes more important in high field imaging. The shimming technique in which axial, sagittal, and coronal section inhomogeneity maps are obtained in one scan is developed, and the shimming method based on the analysis of spherical harmonics of the imhomogenity map is applied. The proposed technique is applicable to a localized shimming as well. High resolution spiral-scan imaging was successfully obtained with the proposed higher order shimming. Conclusion: Proposed pulse sequence for rapid measurement of inhomogeneity map and higher order shimming based on the inhomogeneity map work very well at 3 Tesla MRI system. With the proposed higher order shimming and localized higher order shimming techniques, high resolution spiral-scan images are successfully obtained at 3 T MRI system.