• 상하수도학회지
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• 제21권4호
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• pp.485-491
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• 2007

The fluctuation of inlet flow to a water treatment plant makes a serious problem that it can change the filtration rate abruptly, and ultimately occur the breakthrough of the detained particles inside filter media. Also, since it takes very short time (about 10 minutes) for the surface wave occurred from the fluctuation of inlet flow to reach the filtration process, it is impossible to control the filtration rate stably. Therefore, this study was conducted to evaluate the effect of daily flow-rate fluctuation on the performance of sand filtration process, and to suggest the dual media composition for coping with that effect. Comparative column tests have been carried out for various dual media (sand and anthracite) compositions. From the results of column tests, dual media, especially in the case of sand 45cm/anthracite 30cm, is more effective to cope with the effect of flow-rate fluctuation on the performance of filtration than single media (only sand). In addition, irrespective of dual media composition, managing ability to cope with that fluctuation tends to be weak at the end of allowable filtration duration time,

• Journal of Mechanical Science and Technology
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• 제20권3호
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• pp.366-375
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• 2006

In this paper, it is intended to introduce a method to solve multi-objective optimization problems and to evaluate its performance. In order to verify the performance of this method it is applied for a vertical roller mill for Portland cement. A design process is defined with the compromise decision support problem concept and a design process consists of two steps: the design of experiments and mathematical programming. In this process, a designer decides an object that the objective function is going to pursuit and a non-linear optimization is performed composing objective constraints with practical constraints. In this method, response surfaces are used to model objectives (stress, deflection and weight) and the optimization is performed for each of the objectives while handling the remaining ones as constraints. The response surfaces are constructed using orthogonal polynomials, and orthogonal array as design of experiment, with analysis of variance for variable selection. In addition, it establishes the relative influence of the design variables in the objectives variability. The constrained optimization problems are solved using sequential quadratic programming. From the results, it is found that the method in this paper is a very effective and powerful for the multi-objective optimization of various practical design problems. It provides, moreover, a reference of design to judge the amount of excess or shortage from the final object.

• Nuclear Engineering and Technology
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• 제40권7호
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• pp.581-592
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• 2008

In this study, a conceptual pyroprocess flowsheet has been devised by combining several dry-type unit processes; its applicability as an alternative fuel cycle technology was analyzed. A key point in the evaluation of its applicability to the fuel cycle was the recovery yield of fissile materials from spent fuels as well as the proliferation resistance of the process. The recovery yields of uranium and transuranic elements (TRU) were obtained from a material balance for every unit process composing the whole pyroprocess. The material balances for several elemental groups of interest such as uranium, TRU, rare earth, gaseous fission products, and heat generating elements were calculated on the basis of the knowledge base that is available from domestic and foreign experimental results or technical information presented in open literature. The calculated result of the material balance revealed that uranium and TRU could be recovered at 98.0% and 97.0%, respectively, from a typical PWR spent fuel. Furthermore, the anticipated TRU product was found to emit a non-negligible level of $\gamma$-ray and a significantly higher level of neutrons compared to that of a typical plutonium product obtained from the PUREX process. The results indicate that the product from this conceptual pyroprocessing should be handled in a shielded cell and that this will contribute favorably to retaining proliferation resistance.

• 정보처리학회논문지D
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• 제16D권5호
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• pp.737-746
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• 2009

SOA의 출현은 비즈니스 및 IT 환경에 많은 영향을 주었고 학계 및 산업에서 많은 연구가 진행 중이다. 향후 서비스는 폭발적으로 증가할 것이며, 서비스를 컴포지션하여 비즈니스 기회를 창출하고 IT는 이를 지원할 것이다. 그러나 컴포지션의 대상이 되는 서비스를 선정하는 연구는 부족한 실정이다. 본 연구는 서비스 컴포지션 대상을 선정하는 프레임워크를 제안하는 것이며, 선정 방법으로는 Analytic Hierarchy Process 기법을 활용한다. 본 연구의 결과는 서비스 조합시 서비스의 기능/비기능 속성을 반영하고 다양한 이해당사자의 관점과 다수 선정 기준을 적용 하여 서비스 선정을 가능하게 하였다.

• 한국실내디자인학회논문집
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• 제23권2호
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• pp.166-173
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• 2014

This study analyzed visual-perceptual centrality as a measure to solve the confusion that might occur in visitor's movement in analyzing contemporary museums that have recently expand. Also, this study proposed a new methodology to understand the relationships of the occurrence and convergence of visual-perceptual power. The existing visibility graph analysis mostly ends up in identifying nodes corresponding to the physical environment of museums while the newly proposed visibility graph analysis is a methodology that can analyze the landmark on which the visual-perceptual power occurs and converges, by setting visible space elements as analysis variables, which showed a possibility to draw more reliable results in parallel to the existing analysis, and the results of this analysis are as follows. A public museum located in downtown has a limitation that it cannot but be multi-layered as a way to enlarge for the accommodation of a variety of programs on a limited site. Also, this study found that the problem of visitor orientation occurring in the multi-layer process was solved by a major space which was visual-perceptually void. Also, its types can be summarized into two types: One is setting parameter spaces (ramps, staircases, hallways) linked visual-perceptually to the major space and the other is solving the confusion of the visitor's movement by composing a simple exhibition space. In particular, it is judged that the type solving the confusion of the visitor's movement by composing a simple exhibition space also had a relationship with changes in the characteristics of the exhibited works by period. In addition, it was found that the entrance also appeared in two types: dependent type and independent type in the major space according to the characteristics of the major space.

• 자원리싸이클링
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• 제21권4호
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• pp.76-85
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• 2012

조명기기는 일반적으로 램프벌브 내에 수은을 포함하고 있기 때문에 그대로 폐기하면 환경오염 등을 야기하는 우려가 있다. 한편, 조명기기의 수명은 방전특성의 저하 등에 근거하기 때문에 형광체층의 구성 재료인 형광체는 회수, 재생함으로써 재생형광체로서 재이용할 수가 있다. 또한, 유리벌브를 구성하는 유리재료에 관해서도 재이용이 가능하다. 본 연구에서는 폐조명기기의 재활용기술에 대한 특허와 논문을 분석하였다. 분석범위는 1977년~2011년까지의 미국, 유럽연합(EU), 일본, 한국의 등록/공개된 특허와 SCI 논문으로 제한하였다. 특허와 논문은 키워드를 사용하여 수집하였고, 기술의 정의에 의해 필터링하였으며 특허와 논문의 동향은 연도, 국가, 기업, 기술에 따라 분석하여 나타내었다. 폐조명기기로부터 금속을 회수하는 방법으로 산에 침지시켜 희토류 금속을 회수하는 기술이 주종이었으며 무해화 기술은 필터를 이용하여 수은을 제어하는 기술이 대부분이었다.

• E2M - 전기 전자와 첨단 소재
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• 제10권6호
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• pp.519-527
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• 1997

The micro crack was occurred where the stress concentrated by the thermal stress which was induced during the cooling period after molding process or by the various reliability tests. In order to estimate the possibility of development from inside micro crack to outside fracture, the fracture toughness of EMC should be measured under the various applicable condition. But study was conducted very rarely for the above area. In order to provide a was to decide the fracture resistance of EMC (Epoxy Molding Compound) of plastic package which is produced by using transfer molding method, measuring fracture is studied. The specimens were made with various EMC material. The diverse combination of test conditions, such as different temperature, temperature /humidity conditions, different filler shapes, and post cure treatment, were tried to examine the effects of environmental condition on the fracture toughness. This study proposed a way which could improve the reliability of LOC(Lead On Chip) type package by comparing the measured $J_{IC}$ of EMC and the calculated J-integral value from FEM(Finite Element Method). The measured $K_{IC}$ value of EMC above glass transition temperature dropped sharply as the temperature increased. The $K_{IC}$ was observed to be higher before the post cure treatment than after the post cure treatment. The change of $J_{IC}$ was significant by time change. J-integral was calculated to have maximum value the angle of the direction of fracture at the lead tip was 0 degree in SOJ package and -30 degree in TSOP package. The results FEM simulation were well agreed with the results of measurement within 5% tolerance. The package crack was proved to be affected more by the structure than by the composing material of package. The structure and the composing material are the variables to reduce the package crack.ack.

• 디자인학연구
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• 제19권1호
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• pp.109-118
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• 2006

이 연구는 4명의 경력을 가진 산업디자이너를 대상으로 프로토콜 분석을 통해 디자인행위를 탐색하기 위한 사례연구이다. 본 연구에서는 디자인정보양상, 프로세스의 패턴, 해결안의 질적 평가간의 관계를 디자인정보와 디자인프로세스에 기반한 상호보완적 코딩스킴 (Coding Scheme)을 사용하여 분석하였다. 또한 개인창의성모드 (Personal Creativity Mode)와 디자인 행위와의 관계들도 함께 분석하였다. 디자인프로세스에서는 각 디자인전략행위들이 균등하게 분배되어야 좋은 디자인결과물을 얻기 위한 선결조건으로 작용한다는 사실이 발견되었다. 또한 정황과 외부적 지식, GF(General Feathers)에 관한 디자인정보가 많을수록 독창적 디자인 컨셉이 만들어 지는데에 기여하는 것으로 보인다. PCMT에 관해서는 디자인창의성과의 차이성은 나타나지 않았고, 디자이너의 개인성향과 디자인행위간에만 작은 관련성이 드러났다. 이 사실은 실험에 참가한 디자이너들이 경험 이 많은 디자이너라는 것으로 설명될 수 있다. 향후 초보디자이너와 전문디자이너간 디자인정보와 프로세스에 기반한 프로토콜데이터를 통해 나타나는 차이성에 관한 연구와, 개인 디자인 프로세스패턴들이 디자인팀 구성에 있어 어떻게 활용될지에 대한 연구가 진행될 수 있을 것이다.

• Journal of the Korean Wood Science and Technology
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• 제23권2호
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• pp.55-69
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• 1995

The primary objective of this research was to investigate optimum manufacturing condition of thin composite panels composed of sawdust, polyethylene film and polypropylene net. At the study the experiment was designed to make thin board in which sawdust offers effectiveness as core composing material, polyethylene as adhesive with added urea resin, and polypropylene as stiffness and flexibility in the composition panel. 100 types of thin composite panels were manufactured according to press-lam and mat-forming process of various hot pressing conditions(pressure, temperature and time). They were tested and compared with control boards on bending properties(MOR, MOE, SPL, WML), internal bond strength, thickness swelling, linear expansion and water absorption. At the same time the visual inspections of each types of panels were accomplished. The physical and mechanical properties of composite types passed by visual inspection were analyzed by Tukey's studentized range test. From the statistical analysis, the optimum manufacturing condition of thin composite panels were selected. Compared with two manufacturing processes, mat-forming process performed better than press-lam process in all tested properties. The optimum manufacturing conditions resulted from the experiment and statistical analysis were able to determine as following: the press temperature was shown the most good result at 130$^{\circ}C$ in mat forming process and 140$^{\circ}C$ press lam process, the press time 4 min in both processes, but the press pressure was 25-10kg/$cm^2$ in mat forming and 15k/$cm^2$ press lam process.

• 한국건설관리학회논문집
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• 제8권1호
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• pp.87-95
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• 2007

건설공사의 시공공정을 관리자의 경험적 판단에 의하여 작업팀을 구성하여 운영하면, 시공공정의 진행이 비효율적으로 될 가능성이 많다. 그러나 시공계획단계에서 모의조작을 통하여 자원할당, 공사비, 공사기간의 최적 안을 산출하면 시공공정을 정량화하여 효율적인 운영을 할 수 있다. 본 연구에서는 시공공정을 계획할 때 작업팀 운영의 변화에 따른 자원할당 변동치, 자원 손실비, 총공사비, 공사기간의 최적 안을 모의조작 할 수 있는 수식모형의 시안 식을 제안하였다. 제안된 수식모형을 검증하기 위하여 시공공정의 수평작업역과 수직작업 역이 각각 상이하게 구성된 공동주택 골조공사에 적용하여 시현하였다. 본 연구에서 제시된 수식모형을 적용하여 모의 조작을 실시한 결과가 실제 사례공사에서 적용된 작업팀의 운영실적보다 효율화를 달성하였다.