• Journal of Korean Society on Water Environment
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• v.21 no.3
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• pp.263-266
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• 2005

Comparison between photocatalysis (UV+$TiO_2$) and sonophotocatalysis (Sonication+UV+$TiO_2$) were performed in lab-scale experiments for the treatment of chloroform. The effect of operational parameters, i.e., initial chloroform concentration, $TiO_2$ concentration, UV light intensity and sonication time on the degradation rate of aqueous solution of chloroform has been examined. The optimal conditions for photocatalysis and sonophotocatalysis processes were determined: initial chloroform concentration was 25 mg/L, the concentration of $TiO_2$ was 200 mg/L and UV light intensity was $6.630 mW/cm^2$, respectively. The optimal sonication time on sonophotocatalysis process was 90 min. Under the optimal conditions, sonophotocatalysis was effective for inducing faster degradation of the chloroform.

• Review of KIISC
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• v.17 no.6
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• pp.75-86
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• 2007

정보보호 시스템 평가 인증 제도는 정보보호 시스템의 객관적이고 공정한 평가를 통하여 공신력 있는 제 3자로부터 안전성과 신뢰성이 검증된 정보보호 시스템 사용을 권장하고, 이를 통하여 우수한 정보보호 제품 개발을 유도하고 국내 정보보호 산업 육성에 기여하기 위한 것이다. 우리나라는 2006년 5월 CCRA에 인증서 발행국(CAP)으로 가입함으로써 국내에도 IT 제품의 보안성 평가를 위한 평가자 자격기준 개발이 필요한 실정이다. 따라서 본 고에서는 해외 CCRA CAP국의 평가자 자격기준을 비교 분석하여 국내 실정에 맞는 평가자 자격기준을 제안하고자 한다. 본 고에서 제안하는 자격 기준은 국제적으로 인정받을 수 있는 평가자 자격기준 도출 및 평가기관 설립에 요구되는 평가자 선발에 활용할 수 있을 것으로 기대한다.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.20 no.6
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• pp.55-61
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• 2018

This study improved the water repair materials of the polyacrylic system applied to concrete structures by controlling expansion, strengthening water resistance, and improving cohesiveness. The improved polyacrylate repair materials were evaluated against the existing products to verify their performance and level of improvement, and applied on-site to the concrete structures that are leaking the improved water. The verification method measured the presence of water leaks and the moisture content of concrete inside. Moisture levels were measured for two months before and after material installation, and at least 0.8 - 1.7% of humidity was reduced after installing polyacrylic resin, and no leakage was found.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.241-242
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• 2019

This technology is a water leak repair technology using composite materials of concrete structures that block leakage of structures by injecting rapid microcement into the face of underground concrete to block water and injecting flexible glycidylacrylate. Rapid micro cement system repair materials are mixed with fine fibers to improve the flexural sensitivity of the material and to form a layer that blocks stabilized water at the back of the structure by allowing rapid and tight spatial filling during injection with high cohesion The glycidylacrylate repair material can control the expansion rate, and the external stress also has the characteristic that the form of the material is not destroyed or separated, which can also be applied to vibrating induced structures that produce repetitive fatigue loads, and has an effective durability in saline, alkali, acid (chloric acid, sulfuric acid, nitric acid).

• Proceedings of the Korea Information Processing Society Conference
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• 2013.05a
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• pp.979-982
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• 2013

위치정보를 이용한 서비스가 요구가 증가함에 따라, 실외를 중심으로 이뤄지던 위치정보서비스는 실내를 중심으로 요구되고 있다. 더불어 좀더 정확한 실내측위 시스템에 대한 필요성도 증가되고 있다. 최근의 위치 정보 서비스는 스마트폰의 보급과 함께 모바일 기기의 환경이 이용되고 있다. 본 논문은 스마트 디바이스 기반으로 WLAN(Wireless Local Area Network)과 DATABASE 를 이용한 Fingerprinting 방식을 제안한다. 또한 기존의 Fingerprinting 방식에 스마트 디바이스에 내장된 Gyroscope sensor 를 이용하여 모바일 환경에서 일부 영역에서 발생할 수 있는 신호의 오차를 보정하는 새로운 방법도 제시한다. 실제 테스트 환경을 구축하여 실험한 결과도 제시하였다.

• Journal of Korean Port Research
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• v.6 no.2
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• pp.25-31
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• 1992

Herein we investigate the mass transport velocity caused by the viscosity near the ocean structure such as circular pile and inclined breakwaters. The mass transport velocity which is represented by the sum of the Eulerian velocity and the stokes drift were derived by Carter, Liu and Mei(1973). The tangential components of the inviscid velocity field at the bottom needed in the calculation of the mass transport velocity is obtained by solving the scattering problem due to breakwaters. The matched asymptotic expansion technique is employed to obtain the inviscid flow fields scattered by inclined breakwaters. The numerical results show that heary sediments tends to be deposited near the center of breakwaters and that the narrowing of the entrance width results in reduction of the magnitude of mass transport.

• Journal of Korean Port Research
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• v.9 no.1
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• pp.57-63
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• 1995

In this paper we examine the mass transport within the boundary layer near the sea bottom. The fluid domain is seperated into inner and outer region of boundary layers. In outer region, the wave field is assumed to be inviscid and irrotational. When the incident waves enter the arrays of circular cylinders, the scattering of water waves by an array of N bottom mounted vertical circular cylinders is solved using the method proposed by Linton & Evans under the potential theory. In inner region, the Navier-Stokes equation must be satisfied with boundary conditions at the boundary later and bottom is to be represented by the sum of the Eulerian mean drift and the Stokes' drift.

• Proceedings of the Korea Information Processing Society Conference
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• 2009.11a
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• pp.179-180
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• 2009

본 논문은 웨어러블 플랫폼 구성 기술로써 e-Textile Fabric Area Network (e-FAN) 시스템을 소개하고, e-FAN 시스템에서의 브릿지 노드를 이용한 네트워크 확장 방법을 제안한다. E-FAN 은 직물 소재의 제품에 센서, 엑츄에이터, 프로세서 등의 다양한 정보 처리 유닛이 전도성사로 연결되는 구성되는 네트워크이다. 본 논문은 이러한 e-FAN 시스템에서의 e-FAN 브릿지 노드 (e-FAN Bridge Node; eFANBN)을 활용한 네트워크 확장 방법을 제시한다. E-FAN 브릿지 노드를 활용한 네트워크 확장 방법을 통하여 다양한 종류의 전도성사를 통신 매질로 하는 네트워크 세그먼트를 통합하여 내고장성을 지원하는 네트워크로 확장한다.

• Journal of Korean Port Research
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• v.10 no.1
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• pp.53-61
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• 1996

This paper describes the effect of wave control using submerged flat plate by the numerical calculation and the hydraulic model test. The boundary element method is used to develop a numerical solution for the flow field caused by monochromatic oblique waves incident upon an infinitely long, sumerged flat plate situated in arbitrary water depth. The effect of wave blocking is examined according to the change of length, submerged depth of flat plate and incident angles. Numerical results show that longer length, shallower submergence of flat plate and larger incident angles enhance the effect of wave blocking. To validate numerical analysis method, hydraulic model test was conducted in 2-D wave flume with 60 cm metal sheet. Reflected waves are extracted from water surface elevation in front of the location of a submerged plate by least square method with 3 wave gages. From comparing experimental results with numerical results, efficiency of numerical analysis method by this study could be confirmed well within wide ranges of wave frequencies.

• Journal of Korean Port Research
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• v.10 no.1
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• pp.15-23
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• 1996

In this paper, the numerical model to analyze the wave absorbing performance of upright perforated plates is developed under the linear potential theory. If the drag force is dominent to the inertia force in passing perforated plate, the characteristics of perforated plates are determined by a nondimensionlized real-value of G or a length scaled real-value of a. The parameters (G,a), which depend on the drag coefficient, porosity and local shape of plates, can be readily obtained by simple experiments. We investigated the reflection coefficients over a wide frequency range according to the arrays of perforated plates with different values of G and a. We found that the wave absorbing system using the arrays of upright perforated plates is sufficient to install in the ocean engineering basin.