• Journal of Korean Society of Water and Wastewater
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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.

• The KIPS Transactions:PartD
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• 제16D권5호
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• pp.737-746
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• 2009

The appearance of SOA affects business and IT environment and many studies on SOA is progressed in academics and industries. Service will increase extremely and make business opportunity by composing service. In addition, It will support it. However, studies on selection of a service composition target are insufficient. In this study, we propose a framework that select a service composition target so we use Analytic Hierarchy Process methodology. As a result of this study, we enabled service selection to apply functional/non-functional attributes of services, various stakeholder's view and some selection criteria with service composition.

• Korean Institute of Interior Design Journal
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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.

• Resources Recycling
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• 제21권4호
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• pp.76-85
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• 2012

Fluorescent lamps generally involve mercury within their lamp bulbs. Thus if the lamps are disposed as they are, it might cause environmental pollution. On the other hand, as the life of the lamps depends on the degradation of the discharge performance, the fluorescent substance composing the fluorescent substance coating can be recycled by reusing them as the recycled fluorescent substance. Also, the glass material composing the glass bulbs can be reused. The range of search was limited in the open patents of USA (US), European Union (EU), Japan (JP), Korea (KR) and SCI journals from 1977 to 2011. Patents and journals were collected using key-words searching and filtered by filtering criteria. The trends of the patents and journals was analyzed by the years, countries, companies, and technologies. Recovery method of metals from spent fluorescent lamps is mainly the focus on the recovery of precious metals using acid treatment and, detoxification technology is related with controlling process of mercury using a filter system.

• Electrical & Electronic Materials
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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.

• Archives of design research
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• 제19권1호
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• pp.109-118
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• 2006

A case study bas been conducted to explore design activities of four expert designers through protocol analysis, We examined relations among design information, process patterns and solution qualities with two complementary coding schemes based on design contents and design process, Relation between personal creativity modes and design activities has been examined as well. Regarding design process, an adequate distribution of activities in process may be necessary to bring out a good solution. It seemed that the more design contents about context, external knowledge, and general feature are used, the more unique design concepts are made. Regarding personal creativity modes, not much of differences in that design activity were observed while only a few relations between designer's personality and design activity were observed. The fact that the designers participated are all experienced designers could explain this. Investigation on the differences between novice designers and expert designer reflected in protocol data based on design information and design process coding scheme is to be done. Also, how personal process patterns observed through this protocol analysis can be utilized in composing design team.

• 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.

• Korean Journal of Construction Engineering and Management
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• 제8권1호
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• pp.87-95
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• 2007

If construction process operate composing work team by judgment manager's experience, possibility that progress of construction process becomes as inefficient is much. But, If produce optimal proposal of resources allocation, construction cost and duration through simulation at work plan step, work schedule because do quantification efficient operate do on. When plan construction process in this research, resources allocation by change of work team operation change, resources cost loss, total cost, optimal proposal of construction duration tentative plan of numerical formula model that can do simulation propose. Apply and revealed to apartment house framework which horizontal work area of process and vertical work area are composed as is each different construction process to verify proposed numerical formula model. Achieved efficiency than work team's operation results which apply numerical formula model that is presented in this research and enforce simulation is applied in actuality example construction.