• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.1
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• pp.48-54
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• 2002

This paper is described the indirect induction heated boiler and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter which can operate in the frequency range from 20 kHz to 50 kHz. A specially designed induction heater is composed of laminated stainless plates, which have many tiny holes and are interconnected by spot welding. This heater is inserted into the ceramic type vessel with external working coil. This working coil is connected to the inverter and turbulence fluid through this induction heater to moving fluid generates in the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from a practical point of view.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.6
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• pp.1177-1192
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• 2018

The objective of this study is to develop the existing drainage system for catching the partial leakage of tunnel structures operating in cold region. The drainage system consists of drainage board, Hotty-gel as a waterproofing material, cover for preventing protrusion of Hotty-gel, air nailer, fixed nail, pipe for collecting ground leak, pipe for conveying ground leak, wire-mesh, and sprayed cement mortar. The drainage systems were installed in conventional concrete lining tunnels to evaluate the site applicability and constructability. The performances of waterproof and the drainage in the drainage system were evaluated by injecting 1,000 ml of red water in the back of the drainage system at 7 days, 14 days, 21 days, 28 days, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months and 8 months. During 8 months of field test, the average daily temperature of the tunnel site was measured from $-16.0^{\circ}C$ to $25.6^{\circ}C$. The daily minimum temperature was $-21.3^{\circ}C$ and the daily maximum temperature was $30.8^{\circ}C$. There was no problem in waterproof and drainage performance of the drainage board in the drainage system. However, the pipe for conveying ground leak had the leakage problem from 14 days. It is considered that the leakage of the pipe for conveying ground leak was caused by the deformation of the pipe of the flexible plastic material having a thickness of 0.2 cm by using the high pressure air nailer and the fixing pin and the insufficient thickness and width of the hotty-gel for preventing the leakage.

• Explosives and Blasting
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• v.22 no.3
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• pp.13-26
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• 2004

This work reports results of our study on the dynamic response of buried pipelines depending on their boundary conditions. We have studied behavior of the buried pipelines both along the axial and the transverse direction with a boundary condition of free ends. The buried pipelines are modeled as beams on elastic foundation while the seismic wave as a ground displacement in the form of a sinusoidal wave. The natural frequency, its mode, and the effect of parameters have been interpreted in terms of the free vibration. In order to investigate the response on the earthquake, the resulting frequency and the mode shape obtained from the free vibration have been utilized to derive the mathematical formula for the farced vibration. We have also completed the computer program to simulate the time-displacement graphs of the pipe lines with free ends for both cases of vibrations.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.437-444
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• 2018

The purpose of this study is to comprehend the trend of digital experience centers' development direction and to find out the types of experiences, the characteristics of interaction and the attribute of contents by selecting 4 digital experience centers opened from 2008 to 2018. The types of digital experiences are operation, sensibility, reaction and induction based on precedent studies. The types of interaction are operation, touch and sensor. The attributes of contents are game, play and education. The result shows that the ratio of operation experiences is gradually higher. In the types of interaction, the trend is switching to operation and touch. The offer of experience activities by play type is getting higher. This study is intended to help create an empirical interaction of the content of the children's digital experience centers that will be deployed in the future.

• Journal of Gastric Cancer
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• v.6 no.4
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• pp.284-290
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• 2006

Purpose: Many previous studies have suggested that cyclooxygenase-2 (COX-2) over expression is closely related to angiogenesis. However, few have reported the relationship between COX-2 and lymphangiogenesis which is still unclear, The aim of this study was to determine the relationship between COX-2 expression and lymphangiogenetic factor, VEGF-C, in human gastric cancer and to correlate COX-2 and VEGF-C expression with other clinocopathological features to investigate whether COX-2 contributes to lymphangiogenesis and enhances lymph node metastasis. Materials and Methods: One hundred patients who underwent curative radical surgery in Hanyang University hospital from July 1998 to June 2001 were selected. The expression of COX-2 and VEGF-C were detected by using immunohistochemistry, and the relationships between these two parameters and several clinicopathological factors (gender, stage, lymph node status, tumor location, Lauren classification and angioinvasion) were determined. Results: Increased COX-2 expression was found in 86 of 100 tumor samples (86%) and in 70 of 100 tumor samples (70%) with VEGF-C. A high correlation between VEGF-C expression and lymph node metastasis was observed (P=0.033) along as well as COX-2 expression (P=0.012). Also, there was a significant correlation between COX-2 and VEGF-C expression (P=0.026), yet no correlation were found between COX-2 and VEGF-C expression and other clinicopathological parameters. Conclusion: Our study suggests that COX-2 expression contributes to lymphangiogenesis by mediating VEGF-C and finally promoting lymph node metastasis.

• Korea Science and Art Forum
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• v.25
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• pp.227-240
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• 2016

This study aims to examine how visitors in science centers interact with gesture-based exhibits from embodied cognition perspectives. Four gesture-based exhibits in two science centers were selected for this study. In addition, we interviewed a total of 14 visitor groups to examine how they perceived the property of gesture-based exhibit. We also interviewed four experts to further examine the benefits and limitations of the current gesture-based exhibits in science centers. The research results indicate that the total amount of interaction time between visitors and gesture-based exhibits was not high overall, implying that there was little of visitors' immersive engagement. Both experts and visitors expressed that the current gesture-based exhibits tend to highlight the novelty effect but little obvious impacts linking gestures and learning. Drawing from the key findings, this study suggests the following design considerations for gesture-based exhibits. First, to increate visitor's initial engagement, the purpose and usability of gesture-based exhibits should be considered from the initial phase of design. Second, to promote meaningful interaction, it is important to sustain visitors' initial engagement. For that, gesture-based exhibits should be transformed to promote intellectual curiosity beyond simple interaction. Third, from embodied cognition perspectives, exhibits design should reflect how the mappings between specific gestures and metaphors affect learning processes. Lastly, this study suggests that future gesture-based exhibits should be designed toward promoting interaction among visitors and adaptive inquiry.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.231-238
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• 1983

N-Benzoylglycylanilide and N-benzoylalanylanilide derivatives were synthesized from N-benzoylglycine and N-benzoylalane with anilines. respectively. The products were identified by elemental analysis, IR, UV and NMR spectra with N-benzoylglycylanilide (I), N-benzoylglycyl-o-toluidide(II), N-benzoylglycyl-m-toluidide(III), N-benzoylglycyl-p-toluidide(IV), N-benzoyl-L-alanylanilide(V), N-bnzoyl-L-alanyl-o-toluidide(VI), N-benzoyl-L-alnnyl-m-toluidise(VII), N-benzoyl-L-alanyl-p-toluidide(VIII). These compounds were tested for their phytotoxicity to the germination and seedling growth of rice, radish, green pea plants and turf grass. Among them, N-benzoyl-Lalanyl-m-toluidide had strongly inhibitory effect on the seedling growth of radish seeds, and N-benzoyl-L-alanylanilide showed an inhibitory activity especially upon the seedling growth of turf seeds. In addition, the inhibitory rate of plant seed growth differed with the isomeric position(ortho, meta and para) of methyl group; N-benzoylglycyl-m-toluidide was more effective than both N-benzoylglycyl-o-toluidide and N-benzoylglycyl-p-toluidide derivatives, and also N-benzoyl-L-alanyl-m-toluidide was more effective than both N-benzoyl-L-alanyl-o-toluidide and N-benzoyl-L-alanyl-p-toluidide.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.403-409
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• 1996

Background : Pleural fluid collections may pose a difficult therapeutic problem. Complete drainage of complicated effusions or empyemas and reexpansion of atelectatic lung are important in obtaining a satisfactory clinical outcome. The usual approach to the diagnosis and treatment of patients with pleural effusion and empyema has been with needle thoracentesis and chest tube drainage. With chest tube drainage, technical difficulties and failures may occur as a result of improper tube drainage, particularly when there is a loculation or multiple and inaccesible collections. Fluoroscopic or sonographic guidance facilitates the proper tube insertion and drainage. Method : Twenty eight patients were required for tube drainage due to pleural fluid collections between January 1994 to February 1996. The author compared the results of drainage under applying each different method between blind chest tube insertion and image guided catheter insertion. Results : The conventional blind chest tube group comprised 14 patients; 6 empyema, 6 tuberculous effusion, and 2 parapneumonic effusion. The image guided catheter group of smaller french were composed of 14 patients; 2 empyema, 6 tuberculous effusion, 5 parapneumonic effusion, and 1 effusion of undetermined origin. Radiologic improvement with successful drainage was noticed in 79% with the blind chest tube group, whereas in 93% with the image guided catheter group. The complication with the latter method was unremarkable. Conclusion : Image guided catheter drainage was safe and highly successful in treating patients, not only with complicated effusion also with loculated empyema. Image guided catheter drainage offers an alternative in patients in whom closed drainage is required as the initial treatment.

• The Journal of the Korea Contents Association
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• v.12 no.4
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• pp.485-494
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• 2012

The role of admissions officers in universities is to evaluate applicants from a comprehensive perspective on the basis of diverse bases and materials for evaluation that include not only quantitative, but also qualitative information about applicants. Therefore, the crucial key to ensuring the success of the admissions officer system is to ensure the fairness of admission-related decisions and the integrity of individual admissions officers by urging them to render impartial evaluations based on professionalism and avoidance of bias. This study selected the major realm of the ethical education for admission officers on the basis or experts' opinions, and documentary research, and tried to secure the validity of the composed educational contents through the in-depth interviews and discussions with the incumbent admissions officers. The program must handle subjects that are intimately related to the actual experience of many admissions officers, and must be capable of inducing voluntary compliance from the officers. Therefore, the program suggested by this study focuses on three core areas of ethics: that is, 'interaction with society,' 'ethics and responsibilities involved in admission,' and 'legal obligations and roles of admissions officers.' To this end, it provides twelve sub-topics and learning materials. Providing this kind of ethical education programs for admissions officers will help not only to enhance the professionalism and ethical commitments of admissions officers, but also broadly to establish a fairer and more reliable admissions officer system.

• The Korean Journal of Zoology
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• v.29 no.1
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• pp.13-22
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• 1986

In order to investigate the 'In Vitro 2-Cell Block' phenomenon found in certain mouse strains such as ICR, the present studies have been done. Fertilized eggs (1-cell) and 2-cell embryos recovered from the oviducts of the ICR mouse at the various time intervals after hCG injection to induce ovulation were cultured for 3 or 4 days to examine the capability for further cleavage beyond 2-cell stage. Consequently, it was found that some proportions of the 1-cell or 2-cell embryos recovered at 30 hours post hCG showed their cleaving capability and if the embryos were obtained after 48 hours of hCG injection, they were all at 2-cell stage and most of them developed to the blastocysts in vitro. It was also found that the embryos obtained at 27 hours post hCG showed their stronger capacity of further development in the groups cultured for shorter period than 24 hours in vitro before transferring to the oviduct. Based on the results, it can be inferred that mouse fertilized eggs should be remained inside the oviduct for a certain length of period after fertilization, or they should be cultured for a short period than 12 hours before returning back to the oviduct in order to develop to blastocysts. It was also found that though the embryos under the 2-cell block in culture showed normal feature up to 24 hours under the microscopical observation, they had already lost their capacity for the normal development, and if the culture of the 2-cell embryos was extended to 48 hours, they showed nuclei with heteropyknosis, and the vacuoles were were detected in the cytoplasm of embryonic cell if they were cultured for 72 hours.