• Journal of the Institute of Electronics Engineers of Korea SP
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• v.37 no.5
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• pp.1-8
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• 2000

Point pattern matching schemes for finger print recognition do not guarantee robust matching performance for fingerprint Images of poor quality We present a finger print recognition scheme, where transformation parameters of matched ridge pairs are estimated by Hough transform and the matching hypothesis is verified by a new measure of the matching degree using selective directional information Proposed method may exhibit extremely low FAR(False accept rate) while maintaining low reject rate even for the Images of poor quality because of the robustness to the variation of minutia points.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.10a
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• pp.255-258
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• 2001

광선추적기법은 사진과 같은 고해상도의 영상을 만들어내는 렌더링 기법중의 하나이다. 이 기법은 이미지를 합성하는데 많은 양의 계산 시간을 필요로 한다. 병렬처리 기법이 광선추적에 계산양의 처리 기간을 감소하기 위하여 사용될 수 있다. 본 논문에서는 병렬 광선추적 기법을 MPI(Message Passing Interface)를 사용하여 IBM Supercomputer 상에서 노드의 개수의 증가에 따른 속도 향상과 노드간에 전달되는 메시지의 크기에 따른 성능 향상을 실험하였다. 본 논문에서 실험한 병렬 광선 추적 기법으로 IBM SP 시스템 상에서 다양한 영상을 생성하였다. 영상은 분할가능하고 노드에 분배할 수 있기 때문에 병렬화 범주에 들 수 있으며 부하균형을 맞출 수 있다. 실험에서 프로세서수의 증가에 따른 이상적인 속도향상률(Speed-up rate)을 15개의 프로세서를 사용하여 얻을 수 있었다. 광선을 추적하여 영상을 합성해 낼 때 표현하고자 하는 영상이 단순한 객체로 이루어져 있다면 각 노드에 분산해줘야 할 작업의 크기는 복잡한 객체들로 구성된 영상보다 클 때 더 놓은 성능을 나타내었다. 분산작업의 크기가 작아 상대적으로 통신횟수가 증가할 때 렌더링시 효율저하를 나타내었다.

• Geophysics and Geophysical Exploration
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• v.7 no.3
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• pp.164-173
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• 2004

To delineate geothermal water movement at the Pohang geothermal development site, Self-Potential (SP) survey and monitoring were carried out during pumping tests. Before drilling, background SP data have been gathered to figure out overall potential distribution of the site. The pumping test was performed in two separate periods: 24 hours in December 2003 and 72 hours in March 2004. SP monitoring started several days before the pumping tests with a 128-channel automatic recording system. The background SP survey showed a clear positive anomaly at the northern part of the boreholes, which may be interpreted as an up-flow Bone of the deep geothermal water due to electrokinetic potential generated by hydrothermal circulation. The first and second SP monitoring during the pumping tests performed to figure out the fluid flow in the geothermal reservoir but it was not easy to see clear variations of SP due to pumping and pumping stop. Since the area is covered by some 360 m-thick tertiary sediments with very low electrical resistivity (less than 10 ohm-m), the electrokinetic potential due to deep groundwater flow resulted in being seriously attenuated on the surface. However, when we compared the variation of SP with that of groundwater level and temperature of pumping water, we could identify some areas responsible to the pumping. Dominant SP changes are observed in the south-west part of the boreholes during both the preliminary and long-term pumping periods, where 3-D magnetotelluric survey showed low-resistivity anomaly at the depth of $600m\~1,000m$. Overall analysis suggests that there exist hydraulic connection through the southwestern part to the pumping well.

• Proceedings of the Korea Information Processing Society Conference
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• 2016.10a
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• pp.252-253
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• 2016

가상머신을 탐지하는 기법을 이용하여 현재 프로그램이 동작하는 플랫폼과 운영환경을 알아내는 방법을 제안한다. 가상머신 탐지기법으로 데렉 소더(Derek Soeder, eEye Digital Security)를 사용한다. 이 기법은 예외 명령어를 이용해 프로그램이 가상머신과 네이티브머신 환경에서 작동중인지 알아낸다. 가상머신의 코드 세그먼트 레지스트 영역은 네이티브머신보다 불명확 하다. 이런 메모리 주소체계의 차이를 이용한 가상머신탐지 기법이다. 더 응용하여 프로그램의 작동환경이 디버거(인텔 Pin, Olly dbg)인지 가상머신(VMware, QEMU)인지 혹은 네이티브머신(os: windows7 sp3)인지 구분하는 방안을 제안한다.

• 한국ITS학회:학술대회논문집
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• 2003.11a
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• pp.241-246
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• 2003

• KSBB Journal
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• v.18 no.3
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• pp.174-179
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• 2003

The bacterium NFQ-1 capable of utilizing quinoline (2,3-benzopyridine) as the sole source of carbon, nitrogen and energy was enriched and isolated from soil samples of dead coal pit areas. Strain NFQ-1 was identified as Pseudomonas nitroreducens NFQ-1 by BIOLOG system, and assigned to Pseudomonas sp. NFO-1. Pseudomonas sp. NFQ-1 was used with the concentration range of 1 to 10 mM quinoline. Strain NFQ-1 could degrade 2.5 mM quinoline within 9 hours of incubation. Initial pH 8.0 in the culture was reduced to 6.8, and eventually 7.0 as the incubation was proceeding. 2-Hydroxyquinoline, the first intermediate of the degradative pathway, accumulated transiently in the growth medium. The highest concentration of quinoline (15 mM) in this work inhibited cell growth and quinoline degradation. Pseudomonas sp. NFQ-1 was able to utilize various quinoline derivatives and aromatic compounds including 2-hydroxyquinoline, p-comaric acid, benzoic acid, p-cresol, p-hydroxybenzoate, protocatechuic acid, and catechol. The specific activity of catechol oxygenases was determined to approximately 184.7 unit/㎎ for catechol 1.2-dioxygenase and 33.19 unit/㎎ for catechol 2,3-dioxygenase, respectively. As the result, it showed that strain NFQ-1 degraded quinoline via mainly orthp-cleavage pathway, and in partial meta-cleavage pathway.

• The Korean Journal of Mycology
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• v.26 no.3 s.86
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• pp.365-372
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• 1998

In this study, we evaluated the genetic relationships of fourty seven Pestalotiopsis theae isolates collected from diseased sweet persimon in various places in southern part of Korea using RAPD (Randomly Amplified Polymorphic DNAs) method. As a result of the amplification, eight primers showed total of 86 bands ranging from 0.3 Kb to 3.2 Kb. Among those 86 bands, 84 polymorphic bands were used for bionominal matrix code (0, 1), and UPGMA dendrogram analysis. Similarities among the compared isolates ranged from below 60% to more than 95%. Most of the compared isolates showed $50{\sim}80%$ similarities. The number of isolate pairs which showed more than 80% similarity were 248. The number of isolate pairs which showed $50{\sim}80%$ similarity were 789, and the number of isolate pairs which showed below 50% similarity were 21. Isolate SP-21 (No.9) showed below 50% similarity with all the isolates compared. At 50% similarity level, all the isolates compared, except isolate SP-21 (No.9), were included in one big group. At 65% similarity level, all the isolates compared, except isolate SP-21 (No.9), were divided into three different groups. At 75% similarity level, all the isolates compared, except isolates SP-47 (No. 23) and SP-21 (No.9), were divided into six different groups.

• Proceedings of the KSME Conference
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• 2001.11a
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• pp.105-110
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• 2001

It has recently been raised main issue how solve the problem of insufficient energy. One of the solution is to increase the thermal efficiency of power generation system. For the purpose of high efficiency, it is necessary to increase the steam temperature and pressure. So, the use of modified $9{\sim}12%Cr$ steel having superior creep rupture strength and oxidation resistance is required to endure such severe environment. The evaluation of creep properties of those heat resistance material is very important to secure the reliability of high temperature and pressure structural components. Since creep properties are determined by microstructural change such as carbide precipitation and coarsening, It is certain that there are some relationship between creep properties and hardness affected by microstructure. In this study, SP-Creep ruptured test for newly developed 9Cr steel being used as boiler valve material was performed, and creep properties of the material were evaluated. Also, hardness test were performed and hardness results were related to the creep properties such as LMP and creep strength to verify the availability of SP-Creep test as creep test method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.6D
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• pp.599-604
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• 2010

In this study, the value of travel time was estimated with reflecting the fuel cost according to travel distance. The main objective of this study is whether the addition of the fuel cost as a factor for route choice behavior is appropriate or not, through the stated preference survey. The route choice model was developed using SP survey technique with the consideration of level difference and the value of travel time, toll and fuel costs. Consequently, the fuel cost is identified as a main factor like travel time and toll cost in choosing routes from drivers' viewpoints. Nevertheless, since toll costs are recognized as out-of-pocket expenses whereas fuel costs as periodical expenses, it seems drivers are more sensitive to toll than fuel costs.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.117-122
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• 2005

The purpose of this study is to analyze a correlation between lithology, rock physical property and fracture zone by multiple-logging method, which includes optic borehole image, suspension type PS, resistivity, SP, natural gamma, density, caliper logging located in Ogar test area, Changsu, Pocheon-gun, Gyunggi Province. The outstanding geophysical logging responses particularly shown from lithology pattern, fracture zone, dike zone. in result, the depth of fracture zone which enable groundwater flow estimated at $67{\sim}69m$.