• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.4
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• pp.585-590
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• 2017

In this paper, a low power of safety oriented sidewalk block was implemented using dimming technology using LED and illuminance sensor to prevent glare by high - intensity light source and prevent night traffic accident. The dimming system of this paper used a light bulb color with less fatigue to prevent glare and consumed 6.10Wh power. Also, it is confirmed that the power saving is about 56.9% when compared with the existing system.

• Special Issue of the Society of Naval Architects of Korea
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• 2006.09a
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• pp.89-96
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• 2006

The objective of this paper is to find out a reasonable method for docking analysis of ships. The characteristics of reaction force distribution under docking condition are investigated by carrying out parametric study. To assess the allowable reaction force on keel block from structural strength point of view, two kinds of structural assessment methods are proposed in accordance with expected collapse pattern. In order to verify the proposed method, linear buckling and elasto-plastic large deflection analyses of typical double bottom structure are carried out and the results are compared.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.304-304
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• 2011

최근 도시화에 따른 인구증가와 더불어 도로포장 등 불투수면적의 증가로 인하여 우기시 빗물 침투가 차단되어 도심의 지하수위가 저하되며 토양의 건토화, 열섬현상 등의 문제가 발생하게 되었다. 이러한 문제점에 착안하여 본 연구에서는 투수효과를 최대한 고려할 수 있는 고강도의 친환경 콘크리트 블록(에크스톤 바이오 블록; ECOSTONE-BIO BLOCK)을 개발하였으며 기존 콘크리트 블록의 자연적 빗물침투 억제의 문제점을 일부 개선하였다. 본 블록은 캡슐공법을 사용하여, 공극률은 높이면서(투수성 향상), 강도와 내구성이 유지됨은 물론 캡슐안에 황토성분을 첨가하여, 바이오적인 기능 및 재생골재를 이용한 친환경적 제품으로 투수성, 내구성, 기능성을 극대화 시켰다. 또한 제품표면은 천연 백색돌맹이, 흑색돌맹이의 배합으로 자연석재 느낌을 구현하였으며, 쇼트블라스트 및 커링 표면공정으로 미끄럼저항지수를 조절할 수 있어, 기존 콘크리트 보도블록에 비해 투수율, 내구성, 기능성, 안전성이 우수하여, 안전한 보행환경이 가능한 것으로 분석되었다. 마지막으로, 주변 환경과 잘 어울리도록 디자인된 바이오기능성 친환경 블록으로 도심지역 시공시 투수효과에 따른 지하수고갈방지 및 침수피해에 도움을 주리라 사료된다.

• The KIPS Transactions:PartC
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• v.17C no.1
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• pp.47-60
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• 2010

Randomness is a basic security evaluation item for the most cryptographic algorithms. NIST has proposed a statistical test suit for random number generators for cryptographic applications in the process of AES project. However the test suit of NIST is customized to block ciphers which have the same input and output lengths. It needs to revise NIST's test suit for key derivation functions which have multiple output blocks. In this paper we propose a revised method of NIST's statistical randomness test adequate to the most key derivation functions and some experimental results for key derivation functions of 3GSM and NIST.

• Broadcasting and Media Magazine
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• v.11 no.1
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• pp.68-77
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• 2006

The Cognitive Radio (CR) technology is a promising solution for exploiting the limited spectrum resources and providing flexibility of spectrum usage. Future interactive broadcasting service can be realized by utilizing CR concept, since the up-link return channel can be found by the spectrum sensing method, which is core functional block of the CR system. In this paper, the spectrum sensing technologies of CR system is presented. First the system architecture of the CR with spectrum sensing block is presented. The suggested spectrum sensing technique consists of the coarse and the fine spectrum sensing. The coarse spectrum sensing technique adopted the wavelet transform to provide the multi-resolution sensing feature - Multi-Resolution Spectrum Sensing (MRSS). The fine spectrum sensing technique uses the beneficial properties of the autocorrelation function Analog Auto-Correlation (AAC). The simulation results for the proposed sensing technologies are presented for various incumbent signals.

• The Korean Journal of Pain
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• v.10 no.2
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• pp.254-257
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• 1997

Ganglion impar lies immediately anterior to the sacrococcygeal junction and blockade of the ganglion is used to treat anorectal and perineal pain. Although the technique introduced by Plancarte et at is widely practised, the bent needle is sometimes difficult to position precisely and patients find the procedure painful. We modified this approach of block of ganglion impar by positioning the needle into the sacrococcygeal junction and using the loss of resistance technique. With the patient in the lateral position, a skin wheal was raised at 1-1.5cm below the sacral hiatus. Twenty-three gauge short needle was directly placed into the sacrococcygeal junction with aid of fluoroscopic guidance. From 1 cm behind the anterior margin of the vertebral body in lateral view, we used the loss of resistance technique to confirm the retroperitoneal space. We found this modified approach easier to perform during six blocks for three patients with anorectal or perineal pain. Our modified approach through the sacrococcygeal junction may provide opportunity for wider administration of this procedure because of its simple technique, reduced pain during procedure and decreased risk of infection.

• Journal of Korean Academic Society of Home Health Care Nursing
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• v.24 no.3
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• pp.325-335
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• 2017

Purpose: This study investigated the factors influencing mental health among university students based on ecological perspectives. Method: The subjects for this study were 416 students in two colleges in K province. The instruments used for measurement were: Symptom Checklist (Derogatis, 1977), Ego Resilience Scale (Block & Block, 1980), Perceived Stress Inventory (Cohen, Kamarck, & Mermelstein, 1983), and Social Support Scale (Park, 2002). The data was analyzed using the IBM SPSS program. Result: Ego resilience and perceived stress as intrapersonal factors and friends' support as interpersonal factor were the significant predictors of mental health. It was showed that these factors explained 47% of mental health. Conclusion: This study suggests that the factors influencing mental health are both intrapersonal and interpersonal factors. Thus, the findings of this study provide the basic data to develop a program for mental health of university students based on ecological perspectives.

• The Korean Journal of Pain
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• v.18 no.1
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• pp.23-28
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• 2005

Background: An epidural steroid injection (ESI) is usually used for the treatment of low back pain with radiculopathy. An ESI can be performed by two procedures: I) a lumbar or caudal epidural steroid injection and II) a transforaminal epidural steroid injection. Methods: Ninety-three patients, who had undergone transforaminal epidural steroid injection (Group II), and either a lumbar or caudal epidural steroid injection (Group I), were retrospectively studied. The authors assessed the pain, walking, standing improvement and side effects after each procedure, which were evaluated as being very good, good, fair or poor. Data were collected from the patients medical records and analyzed using the chi-squared test. P < 0.05 was considered significant. Results: There were no statistically significant differences in the pain, walking, standing improvement and side effects between the two groups. However, there was a statistically significant difference in the pain improvement following transforaminal epidural steroid injection in those not effectively responding to an initial lumbar or caudal epidural block in Group II. Conclusions: A transforaminal epidural steroid injection is a useful alternative to a lumbar or caudal epidural steroid injection for low back pain with radiculopathy.

• Journal of Environmental Impact Assessment
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• v.13 no.4
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• pp.153-164
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• 2004

An integration study of time-variable small watershed and stream models (USEPA's SWMM and WASP5) was performed for impact assessment of urbanization on water environment. The study area, the Kyoungan Stream, the tributary of Paldang Lake, was divided into 111 subbasins, based on the topographic condition, land use, and drainage system. RUNOFF block of SWMM was applied to estimate runoff flow and quality. EXTRAN block computed daily and hourly flow according to simulated runoff flow, water supply, and drainage data. SWMM was connected to WASP5 by transforming output file of SWMM into input file of WASP5. The nonpoint source loads and flow data of SWMM were imported to WASP5. The stream was divided into 45 segments based on the watershed delineation. The study included three water quality parameters, BOD, TN, and TP. The validate models were used to examine the impact of urbanization on stream flow and water quality.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.20 no.4
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• pp.3-16
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• 2010

Key derivation functions are used within many cryptographic systems in order to generate various keys from a fixed short key string. In this paper we survey a state-of-the-art in the key derivation functions and wish to examine the soundness of the functions on the view point of provable security. Especially we focus on the key derivation functions using pseudorandom functions which are recommended by NISI recently, and show that the variant of Double-Pipeline Iteration mode using pseudorandom permutations is a pseudorandom function. Block ciphers can be regarded as practical primitives of pseudorandom permutations.