• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.475-485
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• 2000

In this study, an automated optimum design program for steel box girder bridges has been developed for the optimum design of composite steel box girder bridges. The design constraints required for the optimum design of steel box girder bridges are based on the Korean standard bridge specification. Considering characteristics of steel box girder bridges, several approximation techniques, such as artificial constraint deletion, variable linking and stress reanalysis technique etc. are also introduced to enhance the efficiency of optimization. The developed program is mainly composed of major sub-system modules including structural analysis module using commercial structural analysis program such as RM-SPACEFRAME, optimum design module, pre-process module for friendly user input, and post-processor module for office automation. In addition, in order to demonstrate the efficiency and applicability of the developed optimum design program for steel box girder bridges, a few numerical examples are applied. Based on the results of the application, it may be stated that the automatic optimum design program developed in this study can be a prototype model for the developement of optimum design program for other type of bridge.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.32 no.2
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• pp.118-125
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• 2010

Background and Purpose: Bone metastases rarely occur in patients with oral squamous cell carcinoma (OSCC), so the molecular mechanisms of bone metastasis of OSCC remains unclear. Studies with animal models allow progresses in understanding the molecular events for bone metastasis and provide new targets for therapy. So we tried to establish a murine model for bone metastasis of oral squamous cell carcinoma. Materials and Methods: Human OSCC cells (KB cell line) were xenografted to nude mice via direct inoculation into the tibial marrow. Mice with tibial tumors were sacrificed once a week, until seven weeks after the injection of human tumor cells. Growth of tibial tumors were observed by histology. Expression of TGF-$\beta$ and CXCR-4 in bone OSCC (experimental) and subcutaneous tumor (control) was also evaluated by immunohistochemical staining. Results: Bone OSCC was successfully induced by intra-tibial injection of KB cells. Tumor mass was developed in the marrow tissues of tibia and finally invade the endosteum of tibia. Immunohistochemical staining showed higher expression of TGF-$\beta$ in bone tumors than in subcutaneous tumors. Conclusion: A murine model of bone metastasis of OSCC was suggested that imitated the clinical findings of distant vascular metastasis. This bone tumor model should facilitate understanding of the molecular pathogenesis of OSCC bone metastasis, and aid in the developement of treatment strategies against OSCC bone metastasis.

• Clean Technology
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• v.3 no.2
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• pp.36-46
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• 1997

CFC and organic chlorine solvents has been used in the fine machinery and electronics industries for a long time since they have various excellent properties as cleaning agents. However, it is inevitable that alternative cleaning agents should be used since CFC and organic chlorine solvents were identified as ozone-depleting chemicals. There are various alternative cleaning agents. Among them, aqueous/semi-aqueous cleaning agents are environmentally friendly and promising in the long term. And their use and developement are on the increase in advanced countries, but few in our countries. In this paper, the charactistics and major components aqueous/semi-aqueous cleaning agents are analyzed and compared. And various cleaning equipments for aqueous/semi-aqueous cleaning agents such as immersion cleaner, ultronsonic cleaners, power spray cleaner, and vibration or rotational cleaners are compared and evaluated. Finally, important consideration points for selction of a cleaning system are analyzed and suggested in this paper.

• The Journal of the Korea Contents Association
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• v.20 no.3
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• pp.31-40
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• 2020

As a result of reenforcement of livestock industry licensing and livestock related vehicle registration system, pig farm are mandatory for setting stop bar before pig farm entrance and maintaining the records of inlet and outlet to and from pig farm. Also, the first step to the pig farm biosecurity is the control of entrance human, vehicles, animals and the related records including entrance and sterilization. In this study, the pig farm entrance control system using RFID technology and web-server system was developed. For human entrance, contact type RFID reading system(13.56MHz) was developed. And the 900MHz RFID system was used to detect vehicle entrance. The test result shows that system actuating, recognition, saving records to the web server was successful. Then, the full system of human entrance recording unit, vehicle entrance recording unit, entrance control system, human sterilizing booth containing a tablet for inputting visitor's record and sterilization record was tested. The records were wrote to web server DB through the data management web-program. Performance test shows the entrance control and data management in server was successfully operated.

• Journal of the Korean Society for Library and Information Science
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• v.52 no.3
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• pp.273-287
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• 2018

The National Library of Korea, Sejong plays a central role in maximizing the development and provision of policy information services in Korea. In order to perform its functions, systematic and practical strategies for policy information development are essential. Besides, in order to establish the identity of the National Library of Korea, Sejong as a specialized library of policy information services and to maximize the capacity, the development strategies for policy information needs to be suggested. This study, in this regard, propose strategies for the development of policy information collection. Specifically, we suggest that both guidelines of collection development policy for general collection, and practical guidelines of collection development specific to policy information.

• Journal of Korean Society of Disaster and Security
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• v.9 no.1
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• pp.33-38
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• 2016

Real time location system was development for safety management at road and bridge maintenance field. The system can check the real-time location detection, movement history, behavior of a number of laborers. The system consisted of a Bluetooth and ZigBee that uses low-power. It had a very large error that the previous method for the position recognition by triangulation using the RSSI. Because This study proposed a new distance measurement and correction scheme using RSSI and accelerometer. It was evaluated in the maintenance field. A development system were evaluated in the field, the results are shown an error between 0.2 m and 0.4 m. And through the acceleration of history it was confirmed by determining possible to determine the safety situation of the laborers.

• Transactions of the Korean Society of Mechanical Engineers
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• v.11 no.1
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• pp.154-159
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• 1987

In the previously reported Part I, the behavior of the flank wear for carbide tool was studied as a preceeding step to present a simple method for Quick Tool-Life Testing, and the following general equation was obtained $W_{f}$ =(a+bt) $V^{m}$ . In this study the following step-cutting formula for the constants a, b and m in the above general model is derived by using step-cutting data [a numerical formula] To check the validity of the above formula, the comparison is made between the tool-life equation inferred in this method and that inferred in the conventional tool-life testing method, when the wear criterion is 0.3mm. The equation obtained in the present method is V(T')$^{0.57}$=1763 whereas the equation obtained in the conventional tool-life testing method is V(T)$^{0.56}$=1605 The results of the above two formula are satisfactory and also verify the validity of the present research.earch.

• Korean Journal of Veterinary Research
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• v.34 no.3
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• pp.609-617
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• 1994

This study was performed for assessing carcinogenicity of Folpet using medium-term carcinogenicity bioassay. Sprague-Dawley rats aged six weeks divided into four grout's and were initially given an intraperitoneal injection of diethylnirosamine at 200mg/kg body weight. Two weeks later, group 1(negative control) was treated with basal diet. A Folpet was given per oral administration to group 2(100 ppm) and goup 3(1,000 ppm). Group 4 was fed on water containing 0.05% phenobarbital sodium as a promtor for six weeks. At three weeks after beginning of the experiment, partial hepatectomy was performed in all rats. The tumor-promoting effects were examined by the numbers and areas per $cm^2$ of induced glutathion S-tranferase placetal form(GST-P) positive foci in liver, and silver stained nucleolar organizer regions(AgNORs) which have recently introduced as one of the indicators for the cell proliferative activity. As the results, Folpet didn't have tumor-promoting effects on GST-P positive foci developement and AgNORs during promoting stage after initiation, whereas phenobarbital sodium treatment group showed promoting effect. It was concluded that Folpet didn't have promoting effect at 500, 1,000 ppm using this midium-term carcinogenicity bioassay model.

• Korean Journal of Materials Research
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• v.11 no.7
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• pp.569-574
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• 2001

The crystal structure, surface morphology and preferred orientation of the copper electrodeposit were investigated by the using sulfate bath with $SiO_2$suspensions and the cathode substrate Au sputtered. As by the addition of colloidal silica in copper electrolytic bath and Au pre-coating on substrate, the crystal particles of deposits was fined-down, made uniform and the account of particles were increased. Hardness of copper electrodeposits with colloidal silica increased about 15% in comparison with that of pure copper deposit film and (111), (200) and (311) plane of X-ray diffraction patterns were almost swept away, so preferred orientation of the copper deposits changed from (111) to (110) plane by codeposit $SiO_2$ and precoating the substrate.

• The Korean Journal of Mycology
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• v.12 no.2
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• pp.75-77
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• 1984

An undescribed Cercospora leaf spot of pepper grown in a greenhouse was observed at Jinju area in 1983. The symptom of this disease showed frog eyes spot on lower leaves of pepper. Leaves and petiole of pepper plant inoculated with spore suspension of this pathogen app­eared leaf spot after 2 weeks and exhibited cicular, brown frog eyes spot. This fungus was grown slowly on PDA and produce condia on infected leaves. The occurrence of this disease was responsi­ble for factors with high temperature and humidity conditions in the ill-ventilated greenhouse. This causal fungus was identified as Cercospora capsici Heald et. Wolf from the shape and length of the conidiophores, the length of the condia, and pathogenic behaviors.