• Korean Journal of Construction Engineering and Management
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• v.2 no.2 s.6
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• pp.59-67
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• 2001

The purpose of this study is to evaluate economics by the Life Cycle cost(LCC) analysis of Steel Box Girder and Prestressed Box Girder bridge types. The study has been performed as a case study. A questionnaire survey for the repair and replacement cycle has been done in order to predict operation and maintenance costs. For LCC analysis and comparison, the present value technique is used. The results of this study are summarized as follows: (1) A LCC analysis model of Steel Box Girder and Prestressed Box Girder bridge types is suggested through a case study. (2) The repair and replacement cycle of elements of them are investigated using a questionnaire survey. (3) As a result of LCC case study, the type of Prestressed Box Girder bridge is analyzed more economic than Steel Box Girder.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.4
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• pp.310-319
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• 2019

Although mud shrimp (Upogebia Major) provides benefits on the tidal flat ecosystem, it is causing the mass mortality of Manila clam (Tapes philippinarum) and large economic loss to the aquaculture farmer due to spreading in the entire coastal clam farm area of the West Sea of Korea. In this study, a mud shrimp blocking box for cultivating clam was tested to prevent the mud shrimp from invading the habitat of the clam. To determine the effect of the blocking box, the growth characteristics of the clams under various culture conditions were investigated. The shell length, total weight, condition index, the presence of mud shrimp in the box, and the soil decay in the box were examined according to whether the clams were raised in the box or in natural state, whether the box is covered with a net or not and the gap size of the box. As a result, no significant differences in shell length, total weight, and condition index were found between the clam grown in the box and the natural state (P>0.05) without any evidence of invading of mud shrimp to the box. In addition, the soil inside the box was in good condition, not decayed. Therefore, using the mud shrimp blocking box, mud shrimp can be prevented from propagating to the habitat of the clam, thereby contributing to the normal production of the clam and thus to restoring the clam farming.

• Food Science and Preservation
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• v.5 no.4
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• pp.315-319
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• 1998

In order to study the effect of packing materials on the quality of fares during storage period, grapes (Campbell Early) were packed with different materials such as expendable folystyrene (EPS) box, paper board box, biopaper board box, paper board box + small box, EPS box + (EPS dish + Bio-PE film sealing), md EPS box + (EPS dish + wrap sealing). The fruit weight loss was increased with the storage period by all the treatments. Weight loss was 6.38% lower in the EPS box+ (EPS dish + Bio film sealing) during 15 days of storage and 5.53% lower in EPS box + (EPS dish + wrap sealing) than that in the EPS box. The abnormal fruits were more increased in the sealing packing than in the non-sealing packing since water transpiration was prevented in the sealing treatment. Wilting fruits were also fewer in the sealing packing than that in the non-sealing treatment. The taste and appearance quality were worsened with increasing the storage days, whereas the appearance quality of the grapes in the bio paper board box was better. Hardness was scarecely changed in the EP5 box+ (EPS dish + Bio-PE film sealing) treatment than those by the other treatments. The soluble solid and acidity showed very little change but soluble solid content was more decreased in the sealing packing than that by the non-sealing treatment.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.343-349
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• 1987

This study was executed to investigate proper storage conditions for freshness of lunch-box and prevention of lunch-box borne illness. When boiled rice was put into the empty lunch-box without cooling, temperature of the lunch-box was $70^{\circ}C$ to be able to destroy vegetative cell of microoganism in the lunch-box. Temperature of the side-dish canister that is placed on the hot lunch-box was increased from $15^{\circ}C$ to $53^{\circ}C$. The use of the insulator(one to two layer) between the lunch-box and side-dish canister was effective in insulation of the heat that is conducted from the hot lunch-box to the side-dish canister. The insulation layer(asbestos) was also effective to inhibit the decrease of pH value and growth of microoganisms in the toiled rice and side-dish during storage of the lunch-box. The number of microoganisms in the lunch-box covered without cooling was less than in the case of lunch-box covered after cooling; however, the amount of generation in condensed water that is responsible for swelling of boiled rice in the lunch-box occurred much more in the one than in the other, and was a little generated in the case of high temperature storage, insulator use, and when covering the lunch-box after cooling, and pre-evaporation by stirring boiled rice in the cooking pot before filling it. In addition, inserting the heat insulators on and bottom of the lunch-box the boiled rice can be eaten without coldness in winter season.

• Transactions on Electrical and Electronic Materials
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• v.17 no.6
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• pp.359-362
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• 2016

In the PV (Photovoltaic) power system, a junction box collects the DC voltage generated from the PV module and transfers it to the PCS (power conditioning system). The junction box prevents damage caused by the voltage difference between the serially connected PV modules and provides convenience while repairing or inspecting the PV array. In addition, the junction box uses the diode to protect modules from the inverse current when the PV power system and electric power system are connected for use. However, by using the reverse blocking diode, heat is generated within the junction box while generating electric power, which decreases the generating efficiency, and causes short circuit and electric leakage. In this research, based on the purpose of improving the performance of the PV module by decreasing the heat generation within the junction box, a junction box with a built-in bypass circuit was designed/manufactured so that a certain capacity of current generated from the PV module does not run through the reverse blocking diode. The manufactured junction box was used to compare the electric power and heating power generated when the circuit was in the bypass/non-bypass modes. It was confirmed that the electric power loss and heat generation indicated a decrease when the circuit was in the bypass mode.

• Journal of the Korea Society of Computer and Information
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• v.6 no.2
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• pp.90-96
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• 2001

The development of network and the other communication-network can generate serious social problems. So. it is highly required to control security of network. These problems related security will be developed and keep up to confront with anti-security part such as hacking. cracking. In this paper. the proposed multiple nonlinear S-box function which is capable to cipher regardless of key distribution or key-length for these definite problem is proposed and designed in hardware. The proposed multiple nonlinear S-box function increase secret level from using a nonlinear function in multiply for key data utilized in cryptography that generates MDP and MLP in maximum is proposed to prevent cryptography analysis. The designed the multiple nonlinear S-box function in this paper performed synthesization and simulation using Synopsys Ver. 1999.10 and VHDL

• The Korean Journal of Applied Statistics
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• v.14 no.1
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• pp.137-148
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• 2001

Compositional data found in many practical applications consist of non-negative vectors of proportions with the constraint which the sum of the elements of each vector is unity. It is well-known that the statistical analysis of compositional data suffers from the unit-sum constraint. Moreover, the non-linear pattern frequently displayed by the data does not facilitate the application of the linear multivariate techniques such as principal component analysis. In this paper we develop new type of principal component analysis for compositional data using Box-Cox contrast transformation. Numerical illustrations are provided for comparative purpose.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.31 no.3
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• pp.47-53
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• 1999

The effect of coating of liner components with oxidized starch on the properties of corrugated box was examined . Coating was carried out on liner components of B flute, single-wall corrugated board(SK180/S120/K200) , and corrugated box was made from the treated corrugated board. Box was made in a regular slotted container (RSC) style, and box compression strength was determined in the direction of top-to-bottom compression. The compression strength of box coated on outside liner component showed 15.4% improvement for 1.58g㎡ coating. On the other hand, the strength of box coated on outside liner component showed only 1.45% improvement for 1.41g/㎡ coating and 3.46% improvement for 2.32g/㎡ coating. Coating on inside liner component with oxidized starch at low coating weight more significantly improved box compression strength than coating on outside liner component, and the improvement was marked at the coating weight of 1.5-2.5g/㎡. In estimating top-to-bottom box compression strength, the experimental values were closer to the calculated values from McKee's equation suing edgewise compression strength of the combined board measured by column crush test than those from Kellicutt's equation using compression strength of component paperboards measured by ring crush test.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.6
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• pp.705-719
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• 2017

Progressive Collapse Method (PCM) has been broadly applied to predict moment-carrying capacity of a hull girder, however accuracy of PCM has not been much studied. Accuracy of PCM is known to be dependent on how Load-Shortening and -Elongation (LSE) curve of a structural units are well predicted. This paper presents a new procedure to determine LSE datum based on box girder Finite Element Analyses (FEAs) instead of using finite element model of stiffened panels. To verify reliability of FEA results, the simple box girder collapse test results are compared with FEA results of same box girders. It reveals one frame-based box girder model is sufficiently accurate in terms of ultimate strengths of the box girders. After extracting LSE data from the box girders, PCM-based moment-carrying capacities are compared with those from FEAs of the box girders. PCM results are found to be equivalent to FEAs in terms of moment-carrying capacity if accurate LSE data are secured. The new procedure is applied to well-known 1/3 scaled frigate full section. Very excellent moment-carrying capacity of frigate hull section is obtained from PCM with LSE data from box girder FEAs.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.49-53
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• 1994

Advanced Real-Time Satellite Simulator(ARTSS) has been developed to support the telemetry, tracking and command operations of the ETRI satellite control system and to provide satellite engineers a more powerful and informative satellite simulations tool on the desktop. To provide extensive simulation functions for a communication satellite system in the pre-operational and operational missions, ARTSS uses a geosynchronous orbit(GEO) satellite model consisting of the attitude and orbit control subsystem, the power subsystem, the thermal subsystem, the telemetry, command and ranging subsystem, and the communications payload subsystem. In this paper, the system features and functions are presented and the satellite subsystem models are explained in detail.