• Journal of the Korea Institute of Building Construction
• /
• v.22 no.4
• /
• pp.337-345
• /
• 2022

The foundation of high-rise concrete building in coastal areas generally must be installed in an integrated manner, not separately, in order to prevent defects caused by stress on the upper and lower parts of the mounting surface and to manage the process smoothly. However, when performing integrated punching, there is a concern that temperature stress cracks may occur due to hydration heat. Due to the large member size, it is difficult to make a sufficient commitment, so it is necessary to mix concrete with high self-charging properties to ensure workability. In this research, the amount of high-performance spray and admixture used was adjusted as experimental variables to satisfy this required performance. Through the analysis of the results for each blending variable, it was found that the unit quantity was 155kg/m³ and the cement ratio in the binder was 18%, and the target values of the pre-concrete properties and compressive strength were satisfied. A four-component binder(18% cement, 50% slag fine powder, 27% fly ash, 5% silica fume) was used.

• Water Engineering Research
• /
• v.2 no.2
• /
• pp.103-112
• /
• 2001

Issues and problems in formulating South Korea's water resources policy are discussed in terms of water quantity and quality. South Korean needs both water conservation and water supply capability for the growing population and economic activities. The government has attempted to build more large-scale dams to store and supply water for residential, farming and industrial uses, but the environmentalists who emphasize conservation and environmental protection oppose the government. The environmentalists are popular among the general public. Water quality has been deteriorating from point- ad non-point sources. urban and farm runoffs are serious pollutants. All want by preserve water quality. There is no dispute on this matter between the government and the environmentalists. Money is hard to come by to preserve water quality. Economic and financial crises and no self-sufficient local governments' revenue structure are pessimistic. Basic survey on water resources, hydrology and hydraulic is badly needed for the future water resources planning.

• Journal of Technology Innovation
• /
• v.9 no.1
• /
• pp.37-75
• /
• 2001

Technological systems are defined as network(s) consisting of technological infrastructure, industrial organization, and institutional infrastructure. This paper reviews SEMATECH in the U.S. and VLSI Program in Korea as a technological system for semiconductor, which is an advanced technology. Several issues are addressed : how did they get started\ulcorner ; how have they been evolved\ulcorner ; how have the actors and institutions within the system interacted\ulcorner ; what role has the government played in that process\ulcorner Both systems were created by their government, respectively, and they have been evaluated as successful. However, while SEMATECH became complete eough in terms of technological infrastructure, industrial organization, and institutional infrastructure to generate sufficient increasing returns to develop in a self-reinforcing way, a series of VLSI program in Korea is still operated discontinuously under the government subsidy. SEMATECH is more flexible and stable than Korea's VLSI program in that the system has a centralized structure and has been managed and staffed by industry substantially. In addition, both cases show that a technological system may evolve having connections with foreign technological systems and local sub-systems beyond nations, regions and industries. Many other similarities, contrasts, and insights for technological policy from each country's experiences are presented.

• Journal of the Korean Institute of Rural Architecture
• /
• v.1 no.2
• /
• pp.133-144
• /
• 1999

This paper is a study of rural settlement and housing planning in North-Korea. All the housing facilities belong to the government in North-Korea. which leads to the system in which the North-Korea government controls all the housing problems. The North-Korea government actively engages in the settlement of housing problems have close relations with and effects on the urban housing ones. The government has designed to make the rural areas self-sufficient in matters of the rural housing arrangement. They try to make an axis in the middle of each village uniformly and heighten its symbolism of the rural. They place all the symbolic structures in the center to express the ideas of the ruler's. thus making the whole village a study hall where the villagers are forced to learn the ruler's ideas as a way of brainwashing the people.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.431-431
• /
• 2012

A compact tokamak reactor concept as a 14 MeV neutron source is desirable from an economic viewpoint for a fusion-driven transmutation reactor. LAR (Low Aspect Ratio) tokamak allows a potential of high "see full txt" operation with high bootstrap current fractions and can be used for a compact fusion neutron source. For the optimal design of a reactor, a radial build of reactor components has to be determined by considering the plasma physics and engineering constraints which inter-relate various reactor components and are constrained to use ITER physics and technology. In a transmutation reactor, the blanket should produce enough tritium for tritium self-sufficiency and the neutron multiplication factor, keff should be less than 0.95 to maintain sub-criticality. The shield should provide sufficient protection for the superconducting toroidal field (TF) coil against radiation damage and heating effects of the fusion neutrons, fission neutrons, and secondary gammas. In this work, characteristics of transmutation reactor based on LAR tokamak is investigated by using the coupled system analysis.

• 제어로봇시스템학회:학술대회논문집
• /
• 1996.10a
• /
• pp.69-72
• /
• 1996

This paper considers a global resolution of kinematic redundancy under inequality constraints as a constrained optimal control. In this formulation, joint limits and obstacles are regarded as state variable inequality constraints, and joint velocity limits as control variable inequality constraints. Necessary and sufficient conditions are derived by using Pontryagin's minimum principle and penalty function method. These conditions leads to a two-point boundary-value problem (TPBVP) with natural, periodic and inequality boundary conditions. In order to solve the TPBVP and to find a global minimum, a numerical algorithm, named two-stage algorithm, is presented. Given initial joint pose, the first stage finds the optimal joint trajectory and its corresponding minimum performance cost. The second stage searches for the optimal initial joint pose with globally minimum cost in the self-motion manifold. The effectiveness of the proposed algorithm is demonstrated through a simulation with a 3-dof planar redundant manipulator.

• Journal of the Korea Society of Computer and Information
• /
• v.6 no.1
• /
• pp.7-13
• /
• 2001

As the density of VLSI increases, the conventional logic testing is not sufficient to completely detect the new faults generated in design and fabrication processing. Recently. IDDQ testing becomes very attractive since it can overcome the limitations of logic testing. This paper presents a new BIC for the internal current test in CMOS logic circuit. Our circuit is composed of Magnetoresistive current sensor, level shifter, comparator, reference voltage circuit and a circuit be IDDQ tested as a kind of self-testing fashion by using the proposed BIC.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.9
• /
• pp.1985-1988
• /
• 2009

Poly (lactic-co-glycolic acid) (PLGA) nanoparticles loading paclitaxel have been deposited on coronary stents by self-assembling properties of colloidal particles. The layers of the nanoparticles were enhanced to a sufficient mechanical strength by a thermal process under the proper temperature and humidity conditions. In vitro release studies proved the controlled paclitaxel release of the nanoparticle layers. This technique gives rise to a new range of applications for nanoparticles and drug-eluting stents.

• The Korean Journal of Community Living Science
• /
• v.15 no.4
• /
• pp.165-175
• /
• 2004

Food is very important for human being. It is not easy for us to enjoy good life because the situation of food is not good in Korea. The self-sufficient food rate is very low and most of food which we take was produced by industrial agriculture. Food of this kind has some problems with respect to the health of consumer, agriculture, environment and community. In order to secure the true food which is safe and environmentally sound, producers, consumers and community have to work together. Producers must engage in environmental agriculture. They must produce the true food and need to know regional consumers. Consumers must pay attention to the regional agriculture and must participate the production of true food. Local government must open farmers' markets for direct marketing between farmers and consumers. NGOs should educate and organize the producers and consumers.

• Journal of Families and Better Life
• /
• v.18 no.1
• /
• pp.43-52
• /
• 2000

The purpose of this study was to investigate the levels of subjective cost-of-living and its determinants. 328 housewives who live in Seoul were selected as the sample of this study and surveyed by questionnaire method. Results showed that the mean value of subjective cost-of living was 1,280 thousand won for the poverty level of living 1,990 thousand won for the standard level of living and 3,020 thousand won for the sufficient level of living. The determinants of the level very with the level of the living however the actual level of consumption expenditures and the education level of respondents were positively related with all three levels of the subjective cost-of-living while the self evaluation for own life was negatively related with them.