• 대한수학회보
• /
• 제23권2호
• /
• pp.141-148
• /
• 1986

In [1], M. Guignard considered a constraint set in a Banach space, which is similar to that in [2] and gave a first order necessary optimality condition which generalized the Kuhn-Tucker conditions [3]. Sufficiency is proved for objective functions which is either pseudoconcave [5] or quasi-concave [6] where the constraint sets are taken pseudoconvex. In this note, we consider a psedoconvex programming problem in a Hilbert space. Constraint set in a Hillbert space being pseudoconvex and the objective function is restrained by an operator equation. Then we use the methods similar to that in [1] and [6] to obtain a necessary and sufficient optimality condition.

• 천문학회지
• /
• 제46권6호
• /
• pp.261-268
• /
• 2013

Magnetohydrostatic equilibria, in which the Lorentz force, the plasma pressure force and the gravitational force balance out to zero, are widely adopted as the zeroth order states of many astrophysical plasma structures. A magnetic flux-current surface is a surface, in which both magnetic field lines and current lines lie. We for the first time derive the necessary and sufficient condition for existence of magnetic flux-current surfaces in magnetohydrostatic equilibria. It is also shown that the existence of flux-current surfaces is a necessary (but not sufficient) condition for the ratio of gravity-aligned components of current density and magnetic field to be constant along each field line. However, its necessary and sufficient condition is found to be very restrictive. This finding gives a significant constraint in modeling solar coronal magnetic fields as force-free fields using photospheric magnetic field observations.

• Journal of applied mathematics & informatics
• /
• 제27권1_2호
• /
• pp.365-374
• /
• 2009

Under certain conditions, we use augmented Lagrangians to transform a class of generalized semi-infinite min-max problems into common semi-infinite min-max problems, with the same set of local and global solutions. We give two conditions for the transformation. One is a necessary and sufficient condition, the other is a sufficient condition which can be verified easily in practice. From the transformation, we obtain a new first-order optimality condition for this class of generalized semi-infinite min-max problems.

• 대한건축학회논문집:계획계
• /
• 제34권2호
• /
• pp.49-57
• /
• 2018

The purpose of this study is to analyze the current condition of green building education, which is a necessary condition to activate green architecture, with the need to reduce greenhouse gas emissions in the building sector. The main results are as follows. First, the level of education and the level of domestic green architecture were generally underestimated. Second, in order to increase the satisfaction of participants in green building education, it is necessary to increase the number of courses and to increase the number of lecturers who have excellent practical skills. Third, there is a need to strengthen green building programs related to BEMS and green remodeling. Fourth, it is necessary to expand the education on green architecture for the people in the architectural planning and design field and the related field officials. Fifth, green building education needs to be implemented in conjunction with curriculum of elementary, middle and high school. Sixth, it is necessary to diversify the PR(public relations) channels of the green building education program and to provide a way to give the employment increase point when the curriculum is completed. Seventh, there is a need to expand administrative and financial incentives for green architecture in order to revitalize green architecture education.

• Kyungpook Mathematical Journal
• /
• 제59권1호
• /
• pp.73-82
• /
• 2019

In this work, we give necessary and sufficient conditions under which every solution of a class of first-order neutral differential equations of the form $$(x(t)+p(t)x({\tau}(t)))^{\prime}+q(t)Hx({\sigma}(t)))=0$$ either oscillates or converges to zero as $t{\rightarrow}{\infty}$ for various ranges of the neutral coefficient p. Our main tools are the Knaster-Tarski fixed point theorem and the Banach's contraction mapping principle.

• 수산해양교육연구
• /
• 제23권3호
• /
• pp.351-360
• /
• 2011

In order to reduce the casualties of fishing boats, the author analyzed the fishing boat accident on the 412 cases in Korean maritime safety tribunal for the 2005~2009, and then studied the relation between the weather element and the accidents. According to this studies, the occurring ratio of sea casualty for fishing boat in fog weather was appeared 1 boat per 1.6 days. It means that the restricted visibility condition gives the most influence on the fishing boat accident. The casualties in winter season from November to next January occurred 139(33.7%), and small boats less than 50tons broke out more casualties with 68.4%. From this we can find that small fishing boats are very deeply affected on the sea weather condition. According to the boat types for fishing the casualty of jig boat was ranked first, and collision accident account for first with 77.9% for the types of casualties. As mentioned above, most sea casualties for small fishing boats were resulted from the human factors such as poor watch keeping in invisibility and the bad sea condition, it is necessary for navigation operators and the manager to take more attention to the meteorological factors.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.132-137
• /
• 1993

In this paper, a fish drying process control system is proposed, which predicts the proper change with time in weight of the material fish and the drying conditions in advance, based on the performance of skilled worker. In order to implement a human expertise into an automated fish drying process control system, an experimental analysis is made and a model for the process is built. The proposed system divided into two procedures: The procedure before drying and the one during drying. The procedure before drying is for the prediction of necessary drying time. To estimate the necessary drying time, first, the proper change in weight for the product is obtained by using fuzzy reasoning. The condition part of the production rule consists of the factors of fish body and the expected degree of dryness. Kext, the necessary drying time is obtained by regression models. The variables employed in the models are the factors, inferred change in weight and drying conditions. The model for the procedure during drying is also proposed for more accurate estimation, which is described by a system of linear-differential equations.

• 한국농촌건축학회논문집
• /
• 제6권3호
• /
• pp.96-105
• /
• 2004

The purpose of this study is to investigate and analyze the actual condition and utilization planning of rice mills in Korea. Especially there are 64 rice mills at Goesangun, Chungbuk. I had selected six among them and examined. They are comparatively good, worth preserving, and considered to be the historical and local values. The results of study are as follows; First, rice mills of agricultural villages are utilized as the place of learning that people can experience or the agricultural village museum. Second, it can be connected to the sightseeing resources. Therefore, they are utilized as a green tourism. Third, in order to activate small rice mills, it need a governmental support policy. Fourth, it is necessary of the multilateral plan that can be used as a place of village community.

• 한국중재학회지:중재연구
• /
• 제28권4호
• /
• pp.3-42
• /
• 2018

This paper aims to explore ways to develop the arbitration industry in Korea. The prospects for the promotion of the arbitration industry in Korea are never dim. International arbitration competitiveness is somewhat lower than its competitors at present, but the international economic base to support it is solid, and the domestic arbitration environment seems to be sufficient to support the development possibility of arbitration. Since geographical and economic factors have already been defined, Korea must at least improve the arbitration act with passion and vision for the best one. The arbitration act that is the most accessible to arbitration consumers is the best arbitration act. The important thing is to have an arbitration act that makes people want to use more than litigation or other dispute resolution procedures. There is no hope of remaining as a "second mover" in the field of arbitration law. One should have a will and ambition to become a "first mover" even if it is risky. Considering the situation of the current arbitration law, it is necessary to start an arbitration appeal system in order to become a consumer-friendly arbitration law, and it is necessary to examine ways of integrating the grant of execution clause and enforcement application procedures. The abolition of the condition of Article 35 of the Arbitration Act, which rules the validity of the arbitration award, will help promote international arbitration. Exclusion agreements of setting aside against arbitration awards must also be fully recognized. It is also important to publish a widely cited international arbitration journal. In order to respond to the fourth industrial revolution era, it is necessary to support the establishment of a dispute resolution system that utilizes IT technology. In order to actively engage the arbitrators in the market, it is necessary to abolish the regulations that exist in the Attorneys-at-Law Act. There is also a need to allocate more budget to educate arbitration consumers and to establish arbitration training centers to strengthen domestic arbitration education. It is also necessary to evaluate and verify the Arbitration Promotion Act so that it can achieve results. In the international arbitration market, competition is fierce and competitors are already taking the initiative, so in order not to miss the timing, Korea needs to activate international arbitration first. In order to activate international arbitration, the arbitration body needs to be managed with the same mobility and strategy as the agency in the marketplace. In Korea, unlike in Singapore and Hong Kong, it is necessary to recognize that the size of the domestic arbitration market is very likely to increase sharply due to the economic size of the country and the large market potential it can bring from litigation. In order to promote the arbitration industry, what is most important is to make arbitration activities in accordance with the principles of the market and to establish an institutional basis to enable competition. It is urgently required to change the perception of the relevant government departments and arbitration officials.

• Nuclear Engineering and Technology
• /
• 제36권5호
• /
• pp.475-484
• /
• 2004

Extending the lifetime of a nuclear power plant [(hereafter referred to simply as NPP)] is one of the most important concerns in the global nuclear industry. Cables are one of the long-life items that have not been considered for replacement during the design life of a NPP. To extend the cable life beyond the design life, it is first necessary to prove that the design life is too conservative compared with actual aging. Condition monitoring is useful means of evaluating the aging condition of cable. In order to simulate natural aging in a nuclear power plant. a study on accelerated aging must first be conducted. In this paper, evaluations of mechanical aging degradation for a neoprene cable jacket were performed after accelerated aging under tcontinuous and intermittent heating conditions. Contrary to general expectations, intermittent heating to the neoprene cable jacket showed low aging degradation, 50% break-elongation, and 60% indenter modulus, compared with continuous heating. With a plant maintenance period of 1 month after every 12 or 18 months operation, we can easily deduce that the life time of the cable jacket of neoprene can be extended much longer than extimated through the general EQ test. which adopts continuous accelerated aging for determining cable life. Therefore, a systematic approach that considers the actual environment conditions of the nuclear power plant is required for determining cable life.