• 대한수학회지
• /
• 제57권5호
• /
• pp.1103-1118
• /
• 2020

In this paper, we investigate a family of graphs associated to collections of arcs on surfaces. These multiarc graphs naturally interpolate between arc graphs and flip graphs, both well studied objects in low dimensional geometry and topology. We show a number of rigidity results, namely showing that, under certain complexity conditions, that simplicial maps between them only arise in the "obvious way". We also observe that, again under necessary complexity conditions, subsurface strata are convex. Put together, these results imply that certain simplicial maps always give rise to convex images.

• 환경영향평가
• /
• 제20권6호
• /
• pp.823-831
• /
• 2011

파라과이와 한국의 환경영향평가에 관련된 제도와 법률은 환경영향평가 대상사업, 실행방법 및 사후감시 등에서 상이하다. 양국의 환경영향평가 제도 중에는 전혀 관련 없는 것도 있는데, 경제적, 사회적, 문화적, 역사적 그리고 지연조건이 상이하여 양국의 환경영향평가 제도에 영향을 주는 것으로 분석된다. 파라과이에서는 스코핑이 Term of References (TOR)가 준비되는 단계이다. TOR은 환경부에 의해 준비된 특정의 환경영향평가의 요구조건을 포함한다. 파라과이에서는 스코핑 단계에서 환경부의 주도로 주민참여가 진행된다. Environmental Impact Relatorio (RIMA)가 개발사업으로 인해 영향을 받는 지역사회에 시행되고, 간결하고 이해하기 쉬운 표현으로 작성된다. 파라과이에서는 EIS가 승인되기 전에 RIMA를 지역사회에 공개한다.

• 한국실내디자인학회논문집
• /
• 제19호
• /
• pp.11-19
• /
• 1999

This study is about the Characteristics of the Medievalism expressed in the German Architectural Expressionism. The concept of Medievalism is an attitude to revive the social and physical settings on Middle Ages. The social situation and architectural style in the Middle Ages were similar to the German Expressionism in the early 20th-century. The Medieval Characteristics of the German Architectural Expressionism were expressed in two ways -first, organic or sculptural style and second, fantastic or Crystal style. The architects such as Hermann Finsterlin, Henry van de Velde, Erich Mendelsohn, Rudolf Steiner, Hugo H ring, Hans Poelzig belonged to the first tendency, and such as Paul Scheerbart, Bruno Taut, Otto Bartning, Dominikus B hm belonged to the second tendency. The Medieval concept of the German architectural Expressionism was succeeded to Modern Architecture in 1950-1960s'. The architects in 1950-1960's such as Hans Scharoun, Gottfried B hm, Alvar Aalto, J rn Utzon intended to express organic and fantastic mass which was closely connected with the Medival concept of the German architectural Expressionism.

• The Journal of Advanced Prosthodontics
• /
• 제9권6호
• /
• pp.486-495
• /
• 2017

The wide use of chairside CAD/CAM restorations has increased the diversity of the restorative material. For the practitioner, the selection of the appropriate material is difficult amongst the variety offered by the market. Information on the characteristics of the products can be difficult to assess due to the lack of up-to-date classification and the lack of reliability of manufacturer's advertising. The purpose of this article is to structure the data on restorative materials provided by various sources in order for the practitioner to choose the product most suited to the clinical situation. The objective is to classify chairside CAD/CAM materials and to define their characteristics and indications.

• 대한수학회지
• /
• 제54권5호
• /
• pp.1521-1536
• /
• 2017

This paper introduces a representation style of variable binding using dependent types when formalizing meta-theoretic properties. The style we present is a variation of the Coquand-McKinna-Pollack's locally-named representation. The main characteristic is the use of dependent families in defining expressions such as terms and formulas. In this manner, we can handle many syntactic elements, among which wellformedness, provability, soundness, and completeness are critical, in a compact manner. Another point of our paper is to investigate the roles of free variables and constants. Our idea is that fresh constants can entirely play the role of free variables in formalizing meta-theories of first-order predicate logic. In order to show the feasibility of our idea, we formalized the soundness and completeness of LJT with respect to Kripke semantics using the proof assistant Coq, where LJT is the intuitionistic first-order predicate calculus. The proof assistant Coq supports all the functionalities we need: intentional type theory, dependent types, inductive families, and simultaneous substitution.

• ETRI Journal
• /
• 제38권1호
• /
• pp.62-69
• /
• 2016

In this paper, we propose two novel user selection algorithms for multiuser multiple-input and multiple-output downlink wireless systems, in which both a base station (BS) and mobile stations (MSs) are equipped with multiple antennas. Linear transmit beamforming at the BS and receive combining at the MSs are used to avoid interference between users and find a better sum-rate capacity performance. An optimal technique for selecting users would entail an exhaustive search, which in practice becomes computationally complex for a realistic number of users. Suboptimal algorithms with low complexity are proposed for a coordinated beamforming scheme. Simulation results show that the performance of the proposed algorithms is better than that provided by previous algorithms and is very close to an optimal approach with reduced complexity.

• Earthquakes and Structures
• /
• 제8권3호
• /
• pp.511-539
• /
• 2015

The main objective of this study is to analytically investigate the effectiveness of different strengthening solutions in upgrading the seismic performance of existing reinforced concrete (RC) buildings in Nepal. For this, four building models with different structural configurations and detailing were considered. Three possible rehabilitation solutions were studied, namely: (a) RC shear wall, (b) steel bracing, and (c) RC jacketing for all of the studied buildings. A numerical analysis was conducted with adaptive pushover and dynamic time history analysis. Seismic performance enhancement of the studied buildings was evaluated in terms of demand capacity ratio of the RC elements, capacity curve, inter-storey drift, energy dissipation capacity and moment curvature demand of the structures. Finally, the seismic safety assessment was performed based on standard drift limits, showing that retrofitting solutions significantly improved the seismic performance of existing buildings in Nepal.

• Nuclear Engineering and Technology
• /
• 제45권2호
• /
• pp.141-150
• /
• 2013

There is mounting evidence that complex computer system displays in control rooms contribute to cognitive complexity and, thus, to the probability of human error. Research shows that reaction time increases and response accuracy decreases as the number of elements in the display screen increase. However, in terms of supporting the control room operator, approaches focusing on addressing display complexity solely in terms of information density and its location and patterning, will fall short of delivering a properly designed interface. This paper argues that information complexity and semantic complexity are mandatory components when considering display complexity and that the addition of these concepts assists in understanding and resolving differences between designers and the preferences and performance of operators. This paper concludes that a number of simplified methods, when combined, can be used to estimate the impact that a particular display may have on the operator's ability to perform a function accurately and effectively. We present a mixed qualitative and quantitative approach and a method for complexity estimation.

• Industrial Engineering and Management Systems
• /
• 제15권3호
• /
• pp.206-214
• /
• 2016

This paper deals with the no-wait flow shop scheduling problem in order to minimize the total time to complete the schedule or makespan. It is introduced a constructive heuristic which builds the production schedule from job partial sequences by using an appropriate mechanism of insertion. An extensive computational experiment has been performed to evaluate the performance of proposed heuristic. Experimental results have clearly shown that the presented heuristic provides better solutions than those from the best heuristics existing.

• Restorative Dentistry and Endodontics
• /
• 제40권3호
• /
• pp.236-240
• /
• 2015

Traumatic dental injury can result in avulsion of anterior teeth. In young patients, it is a challenge to the dental professional because after replantation, late complications such as ankylosis require tooth extraction. Although prosthetic and orthodontic treatment, and implant placement have been described as the options for intervention, autogenous tooth transplantation could be an effective procedure in growing patients if there is a suitable donor tooth available. This case presents the treatment of a patient who suffered a traumatic injury at 9 years old with avulsion of tooth 21, which had been replanted, and intrusion of tooth 11. Both teeth ankylosed; thus they were removed and autotransplantation of premolars was carried out. After transplantation, the tooth underwent root canal treatment because of pulpal necrosis. Orthodontic treatment began 3 months after transplantation and during 7 years' follow-up the aesthetics and function were maintained without signs of resorption.