• Journal of Environmental Impact Assessment
• /
• v.31 no.6
• /
• pp.369-377
• /
• 2022

The purpose of this study is to explore whether open spaces with land use characteristics of forest green areas can have different influence on the urban heat reduction depending on the location distribution, through the case of Gangneung-si downtown area. As a research method, the InVest Urban Cooling Model, which is a thermal phenomenon analysis model, is employed based on the most recent data available in 2018. In order to focus on the effect of location distribution of open space in the city, the downtown area is set as the observation area, not the entire city. The analysis of the land use location distribution scenarios shows that large-scale forests or clustered forests are more effective in reducing atmospheric heat in the region than several small-scale forests.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.35 no.4
• /
• pp.801-814
• /
• 2015

In this study, a statically simple indeterminate strut-tie model is proposed for the rational analysis and design of simply supported prestressed concrete beams by reflecting all characteristics of nonlinear structural behavior and load transfer mechanisms. In addition, a load distribution ratio that allows to transform the proposed indeterminate strut-tie model to a determinate model is also suggested to help structural designers conduct the structural analysis and design of simply supported prestressed concrete beams by using the strut-tie model method of current design codes. For verifying of the validity of the proposed model and load distribution ratio, the ultimate strengths of 47 simply supported prestressted concrete beams tested to failure were estimated and the results were compared with those by the strut-tie model methods of current design codes.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.11a
• /
• pp.197-200
• /
• 2008

The RC corbels with the ratio of shear span-to-effective depth less than 1 are commonly used to transfer loads from beams to columns. The ultimate strengths and structural behaviors of RC corbels are controlled by the shear span-to-effective depth ratio, strength of concrete, shape and quantity of the reinforcement, and geometry of corbels. In this study, a simple indeterminate strut-tie model reflecting all characteristics of the ultimate strengths and complicated structural behaviors is presented for the design of RC corbels. In addition, a load distribution ratio, defined as a magnitude of load transferred by a horizontal truss mechanism, is proposed to help structural designers perform the design of RC corbels by using the strut-tie model approaches of current design codes. The ultimate strengths of 30 RC corbels tested to failure are evaluated by using the ACI 318-05's strut-tie model code for the validity check of the proposed indeterminate strut-tie model and load distribution ratio.

• Journal of Navigation and Port Research
• /
• v.37 no.4
• /
• pp.351-357
• /
• 2013

Korea is one of the world's major oil importers. And a few domestic ports are operating SBMs for transferring imported crude oil to shore facilities. Recently, Ulsan port is planning to install additional new SBM and to move the existing two SBMs to other places according to the establishment of breakwater caused by the development of Ulsan New Port. However, there are no systematic and consistent standards for fixing the most suitable position domestically and internationally. This study aims to propose the standard of SBM installation using SAW after analyzing the examples of SBM operation and previous researches at home and abroad, and proposing the distribution rate based on opinion survey of exports and related organizations.

• Journal of Korean Society of Steel Construction
• /
• v.21 no.3
• /
• pp.221-232
• /
• 2009

The load distribution factor (LDF) values of simplified composite H beam panel bridges (SCHPBs) that were subjected to one lane and two lane loads were investigated using three dimensional finite element analyses with the computer program ABAQUS (2007). This study considered some design parameters such as the slab thickness, the steel plate thickness, the span length, and the continuity of the SCHPBs in the development of new LDFs. The distribution values that were obtained from these analyses were compared with those from the AASHTO Standard, LRFD, and the equations presented by Tarhini and Frederick, Huo et al., Back and Shin, and Cai. The AASHTO Standard distribution factors for SCHPBs were found to be very conservative. Sometimes, the distribution values from the finite element analyses for interior girders were similar to the results of the AASHTO LRFD, whereas the values for exterior girders were conservative in most cases. The new distribution values that were presented in this study produced LDFs that are more conservative than those from the finite element method. For the simple application of the design to SCHPBs, bridge engineers can use 0.42 for the interior girder and 0.32 for the exterior girder. The proposed values improve the current design procedure for the LDF problem and increase SCHPB design efficiency.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.11 no.3
• /
• pp.253-257
• /
• 2013

Geology, hydrogeology, and geochemistry are the main technical siting factors of a geological repository for spent nuclear fuels. This paper evaluated the siting criteria of overseas geological repository with related to hydrogeologic properties, such as hydraulic conductivity, partitioning coefficient, dispersion coefficient, boundary condition, and water age. Each country establishes the siting criteria based on its important geological backgrounds and information, and social environment. For example, Sweden and Finland that have decided a crystalline rock as a host rock of a geological repository show different siting criteria for hydraulic conductivity. In Sweden, it is preferable to avoid area where the hydraulic conductivity on a deposition hole scale (~30m) exceeds $10^{-8}m/s$, whereas Finland does not decide any criterion for the hydraulic conductivity because of limited data for it. In addition, partitioning coefficients should be less than 10-1 of average value in Swedish crystalline bedrock. However, the area where shows 100 times less than average partitioning coefficients of radionuclides in crystalline rock should be avoided in Sweden. In German, the partitioning coefficients for the majority of the long-term-relevant radionuclides should be greater than or equal to $0.001m^3/kg$. Therefore, it is strongly required to collect much and exact information for the hydrogeologic properties in order to set up the siting criteria.

• Proceedings of the Korean Information Science Society Conference
• /
• 1998.10a
• /
• pp.42-44
• /
• 1998

위성 시스템은 전력 분배, 자세 제어, 열 제어 및 임무 수행에 필요한 탑재체 지원과지상과의 명령 수신 및 측정데이터의 수집을 위해서 프로세서를 내장하고 있다. 임무 수행 및 시스템의 복잡성 여부에 따라서 하나의 프로세서만을 탑재하기도 하지만 여러 개의 프로세서를 탑재하여 기능에 적합하게 분배하여 운용하기도 한다. 아리랑위성은 3개의 프로세서사 탑재되며, 크게 나누어 원격 측정 명령계, 자세 제어계 그리고 전력계에 기능을 담당하게 된다. 하나 이상의 프로세서를 탑재하게 되면 프로세서간의 동기화가 요구되며 프로세서간의 정보 전달을 위해서 통신 채널이 필요하게 된다. 실제로 프로세서간의 동기화는 상호 통신에 있어서 기준 점을 제공하므로 매우 중요한 의미를 가진다. 본 논문에서는 아리랑위성의 동기화는 어떤 방식으로 설계되었으며, 어떻게 운영되는지에 대해 설명한다.

• Proceedings of the Korean Information Science Society Conference
• /
• 2003.10a
• /
• pp.649-651
• /
• 2003

이동성을 가진 다수의 노드들에 의해 자율적으로 구성되는 이동 임시무선망(Mobile Ad Hoc Network)은 홈 네트워크, 센서 네트워크, 개인망 등 다양한 응용 분야로의 적용이 활발히 이루어지고 있지만 무선망이라는 속성 때문에 보안에 취약한 문제점을 안고 있다. 본 논문에서는 이동 임시 무선망에서 이동 노드들간에 보안성을 강화하기 위해 키들을 관리하는 기법을 제안한다. 임시 무선망에서 키를 분배하는 기법 중 완전 분배형 인증 기법이 널리 적용되고 있으며 임의의 노드를 기준으로 주변에 특정 개수 이하의 노드가 활동 중인 경우에도 키 관리를 원활히 할 수 있는 기법을 제안한다.

• Information and Communications Magazine
• /
• v.24 no.9
• /
• pp.60-66
• /
• 2007

이동통신서비스의 증가와 관련 산업의 비약적인 발달은 필연적으로 그 매개체인 이동통신사업용주파수 수요의 폭발적인 증가를 가져왔는데 현재의 주파수배분표는 그 공급이 매우 제한적임을 보여주고 있다. 이러한 변화에 발맞추어 전파관리의 패러다임도 바뀔 수밖에 없는데 기존의 국가관리체제에는 변함이 없을 것이나 이미 할당받은 주파수이 이용을 활성화하기 위하여는 시장 기반의 거래로 그 관리철학이 바뀌어야 한다. 그 제도적 뒷받침을 위하여는 우선 주파수할당시의 용도와 기술기준을 주무부처가 일일이 지정해야 하는가에 대한 근본적인 검토가 필요하고 주파수 양도 임대시 정보통신부장관의 승인제도는 그 법문에 맞게 최소한의 것에 행사되어야 한다. 이는 배분된 주파수대역에서의 주파수이용기술의 발전을 민간레벨에서 촉진시킨다는 의미에서도 매우 중요한 것이다. 더불어 주파수 할당을 비롯하여 전파자원의 분배는 행정절차법이 정한 그 것에 따라야 하며, 나아가 일정한 전파자원의 분배는 관리주체인 정보통신부가 아닌 제3의 독립기관이나 국회의 소관사항으로 하는 것이 바람직하다.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2009.05a
• /
• pp.193-194
• /
• 2009

In this study, a simple indeterminate strut-tie model reflecting all characteristics of the ultimate strengths and complicated structural behavior of pre-tensioned concrete deep beams is presented. In addition, a load distribution ratio, defined as a magnitude of load transferred by a vertical truss mechanism, is proposed to help structural designers perform the strength analysis of pre-tensioned concrete deep beams by using the strut-tie model approaches of current design codes.