• 소성∙가공
• /
• 제27권4호
• /
• pp.222-226
• /
• 2018

Severe plastic deformation (SPD) is a promising method for drastically enhancing the mechanical properties of the materials by grain refinement of metallic materials. However, inhomogeneous deformation during the SPD process results in the inhomogeneous microstructure of the SPD-processed material. We manufactured cylindrical copper specimens of 42 mm in diameter with ultrafine grains (UFG) using an equal channel angular pressing (ECAP) to figure out the relationship between homogeneous microstructure and the number of the processing passes. Two specimens, which are ECAP-processed 4 times (4pass) and 6 times (6pass) each with Route Bc, are prepared for comparison of mechanical properties and microstructure. The results show that the mechanical properties of the two specimens (4pass and 6pass) are similar. Moreover, both the specimens show highly enhanced mechanical properties. The 4pass specimen, however, shows inhomogeneity in hardness distribution, while the 6pass specimen shows a homogeneous distribution. Microstructure analysis reveals that the 4pass specimen has an inhomogeneous microstructure with incompletely refined grain structure. This inhomogeneity of the 4pass specimen could be explained by the circumferential rotation during ECAP process.

• 한국조경학회지
• /
• 제29권5호
• /
• pp.51-59
• /
• 2001

This paper presents a design of the Dasan Children\`s Park which is located Shindang- dong, lung-gu, Seoul which has an area of about 3,678$m^2$. Objectives for the design were to make nature-friendly space, learning space, interesting play space, space for every child, adventure play space, traditional play space, sense of place, and recycle space. For the space compositions a children\`s garden, a traditional play space, and a science play space were located around the S shaped main route. Facilities relating nature, science, culture. environment and adventure play were arranged in the 3 main spaces. The Children\`s Garden is a green space for learning and playing with natural elements. It is composed of a ecological learning space, a children\`s story garden, a children\`s song road, an environmental labyrinth, and a pall space leer handicap children. The Science Play Place is a place space for learning scientific theories through plays to which scientific theories were applied. It is composed of a total play structure, a math experience playground, a \"Keojunggi\" play space, a sound reflecting experience space, arid an infant playground. The Traditional Play Madang(space) is a space for traditional plays. It is composed of a traditional play pattern, a sun dial, and a floor fountain. The Recycle Road is a dragon shaped road fort learning about resource recycling and conservation. It is composed of a dragon head, body, tail space and a dragon bead(cint mani).int mani).

• 한국세라믹학회지
• /
• 제48권1호
• /
• pp.86-93
• /
• 2011

Transparent plasma display can be realized by developing the synthetic chemistry of appropriate nanophosphors and generating nanophosphor-based transparent luminescent layers. For this goal, red-emitting $Y(V_{0.5},\;P_{0.5})O_4$:Eu nanophosphors were synthesized by a facile hydrothermal route at $200^{\circ}C$ for 48 h and the resulting nanophosphors were subsequently annealed at $800^{\circ}C$ at an ambient atmosphere. The crystallographic structure, morphology, and emission property of the as-synthesized and annealed nanophosphors were compared. Choosing 2-methoxyethanol as a dispersion medium and applying a standard sonication, well-dispersed nanophosphor solutions could be prepared. Using these dispersions, visible transparent nanophosphor layers were spin-deposited on glass substrates. By combining $Y(V_{0.5},\;P_{0.5})O_4$:Eu nanophosphor layer/glass substrate as a rear plate with a front plate used in a conventional plasma display panels (PDPs), mini-sized transparent red-emitting PDPs were constructed. Transmittance and luminance properties of two transparent test panels using as-synthesized versus $800^{\circ}C$-annealed nanophosphors were characterized and compared.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2010년도 하계학술대회 논문집
• /
• pp.129-129
• /
• 2010

The conjugated oligomers with rigid and fused-ring structures are of interest for the solution-processable organic thin film transistors (OTFTs) due to their well defined structure and high purity. In this study, alkyl substituted benzothiophene based oligomers were synthesized by a novel route, the key point of which is the acid-induced intermolecular cyclization reaction of aromatic methyl sulfoxides, and were confirmed by $^1H$-NMR and FT-IR studies. The obtained oligomers showed the good solubility in common organic solvents such as hexane, chloroform, and dimethylchloride at room-temperature, which is due to the introduced alkyl chain. The physical and optical properties of the oligomers were studied using differential scanning scalorimetry (DSC), cyclic-voltammetry (CV), UV-visible and PL spectra studies. Solution processed OTFT device based on synthesized oligomers show a high hole mobility of up to $0.01\;cm^2V^{-1}s^{-1}$, $I_{on}/I_{off}$ of $10^5$ and threshold voltage of -14V.

• 복식
• /
• 제50권6호
• /
• pp.59-72
• /
• 2000

The Purpose of this study is to determine the effect of new generation adolescents' clothing consumption values on their evaluation of clothing products. In the positive analysis, a questionnaire survey was conducted. Particularly, based on Sheth's (1991) theory, a focus group Interview was performed to develop the questionnaire on adolescents' clothing consumption values. The results of this study can be summarized as follows: First, young consumers have different values and clothing purchasing behavior from adults. To be specific, adolescents tended to appreciate fashionable and sensual values among clothing consumption values. Second, it was found that adolescents'personal values and their group-wise clothing consumption values affected their evaluation of clothing products. Such a finding may explain the relationship between value system and purchasing decisions. Namely, adolescents' evaluation of clothing products is affected by their value system. This finding supports the consumer value system suggested by the "expectation-value" theory. Thus, values and clothing products evaluation are neither separated from each other nor unrelated, but they affect each other in an abstract hierarchial structure. After all, through the route model, personal values affect clothing consumption values, which in turn affect clothing products evaluation. Besides, the clothing consumption values are affected by gender directly or indirectly. All in all, some specific indices regarding the abstract and hierarchial consumption values could be offered by analyzing the effects of adolescents' consumption values on their evaluation of clothing products in reference to the external clues of price and trademark manipulated, and thereby, the effects of consumption values on the positive clothing products evaluation could be determined in general.n general.

• 한국주거학회:학술대회논문집
• /
• 한국주거학회 2003년도 정기총회 및 추계학술대회
• /
• pp.265-270
• /
• 2003

This expressway passing the address region that is sightseeing of our country must consider in what do a convenience sincerity chase and a cultural side view. A region with development possibility and a spinoff about a cultural element must hold consideration at the same time to a sightseeing resort. This route that passed Gang-Reung, Yang-Yang, Sok-cho was connecting an obstetrics acid, and accessibility along investigation was a hard place. In this region, a classic house is tying scattered, and JeonSaCheong inviting an ancestral mortuary tablet is appearing. The private house was divided during a classic house by using typical Gangwon to the room where a floor was introduced by house with several wings Korean floor heater center form. A characteristic form a characteristic change was appearing on each rooms and structure, a plane according to the times, and to execute extension with a lease in a direction too was able to be seen, and Confucianism a little culture very remained in construction, and a memorial service space, a closet were able to be seen. Also, this local high house had a lot of regions composed of a relative and was with doing in the village that did to these house several houses.

• 전기학회논문지
• /
• 제57권2호
• /
• pp.155-163
• /
• 2008

This paper presents a novel framework for analysis of power system wide-area blackout based on so called fault cascading scenarios. For a given power system operating state, "triggering" faults or a "seed faults" are chosen based on the probabilities estimated from the hazard rates. The fault probabilities reflect both the load and the weather conditions. Effects of hidden failures in protection systems are also reflected in establishing the fault propagation scenarios since they are one of the major causes for the wide-area blackouts. A tree type data structure called a PS-BEST(Power System Blackout Event Scenario Tree) is proposed for construction of the fault cascading scenarios, in which nodes represent various power system operating states and the arcs are the events causing transitions between the states. Arcs can be either probabilistic or deterministic. For a given initial fault, the total probability of leading to wide-area blackout is estimated by aggregating the individual probability of each fault sequence route leading to wide-area blackout. A case study is performed on the IEEE RTS-79(24 bus) system based on the fault data presented by the North American Electrical Reliability Council(NERC). Test results demonstrate the potentials and the effectiveness of the proposed technique for the future wide-area blackout analysis.

• 한국미생물·생명공학회지
• /
• 제18권1호
• /
• pp.103-108
• /
• 1990

효모나 세균을 이용한 메칠글리옥살 대사의 효소학적, 유전학적 연구로부터 생물체들은 메칠글리옥살의 해독을 위하여 보편적이고 다양한 경로를 가지고 있음을 알았다. 이들 대사경로 가운데 글리옥살라아제 I은 메칠글리옥살 해독에 있어서 가장 중요한 경로이다. 글리옥살라아제 I의 분자구조는 효소의 기원에 따라 크게 다르게 나타났고, 아연 이온은 효소활성에 필수적이었다. Pseudomonas putida의 글리옥살라아제 I은 유전자는 메칠글리옥살리아의 제거제로 작용하였고, 또한 세균의 크기를 조절하는 역활을 가지고 있었다. 본 유전자의 염기배열과 정제효소의 아미노 말단을 비교해 본 결과 아미노 말단의 메치오닌 잔기는 번역 후 제거 됨을 알았다. 그밖에 글리옥살라아제 I의 생리학적 역활에 대해서도 논의하였다.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2010년도 춘계학술발표대회
• /
• pp.30.2-30.2
• /
• 2010

Nano-scale p-n junction can generate various nano-scale functional devices such as nanowire light emitting diode, nanowire solar cell, and nanowire sensor. The core shell type nanowire p-n junction has been considered for the high efficient devices in many previous reports. On the other hand, although device efficiency is relatively lower, the cross bar type p-n junction has simple topological structure, suggested by C.M. Lieber group, to integrate easily many p-n junction devices in one board. In this study, for the integration of the cross bar nanowire p-n junction device, a simple fabrication route, employed dielectrophoretic array and direct printing techniques, was demonstrated by the successful fabrication and programmable integration of the nanowire cross bar p-n junction solar cell. This direct printing process will give the single nanowire solar cell the opportunity of the integration on the circuit board with other nanowire functional devices.

• 한국공간정보시스템학회 논문지
• /
• 제10권1호
• /
• pp.29-40
• /
• 2008

최근, 이동 단말기의 확산과 통신 기술의 발달로 인하여 이동 객체들의 과거 궤적 데이터에서 이동 객체의 미동 패턴을 이용하는 응용 서비스의 활용이 점점 증대되고 있다. 특히, 대중교통의 노선 설계나 새로운 도시를 위한 도로 네트워크 설계에 활용하기 위하여, 도로나 철도와 같은 공간 네트워크 상에서 이동하는 이동 객체의 궤적들의 유사 패턴을 활용할 수 있다. 본 논문에서는 공간 네트워크에서 이동 객체 궤적을 위한 시공간 유사 궤적 검색 알고리즘을 제안한다. 이를 위하여 도로 네트워크상에서 실제 도로 네트워크 거리에 기반한 시공간 유사도 측정방법을 정의하고, 효율적인 유사 궤적 검색을 위한 그리드 기반 색인 기법을 제안한다. 마지막으로 본 논문에서 제안하는 유사 궤적 검색 알고리즘의 효율성을 입증하기 위해 제안하는 알고리즘의 성능을 분석한다.