• Title/Summary/Keyword: 김동환

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A Case of Endobronchial Metastasis from Renal Cell Carcinoma 7 Years after Nephrectomy (근치적 신절제술 후 7년만에 기관지내 전이로 발견된 신세포암 1예)

  • Kim, Do Hyun;Kim, Sun Hye;Kim, Dong Hwan;Na, Hyoung Jung;Lee, Ju Hyun;Lee, Sun Min;Kim, Chong Ju;Kie, Jeong Hae
    • Tuberculosis and Respiratory Diseases
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    • v.61 no.5
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    • pp.496-500
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    • 2006
  • A distant metastasis from a renal cell carcinoma is quite common after a radical nephrectomy. For this reason, a5 year scheduled follow up is recommended. However, a distant metastasis 5 years after the resection is quite rare. We encountered an endobronchial metastasis from a renal cell carcinoma that was discovered 7 years after the radical nephrectomy, and did not present during the 5 year scheduled follow up regimen. We report this case with a review of the literatures.

A Study on the Effects of Entry Barriers for the Stock Prices of Venture Businesses. (진입 장벽이 벤처기업 주가에 미치는 영향)

  • Oh Sung-Bae;Kim Dong-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.5
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    • pp.384-390
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    • 2005
  • The purpose of this study is to test empirically the effects of Entry Barriers for the stock prices of Venture Business using the Ohlson Model which is modifying and extending in terms of growth and the potential growth energy. Because the traditional Ohlson model(1995) on which the firm's value is determined only based on abnormal earnings and book value have numerous limitations when we evaluate the value of venture Businesses with high technology and new emerging market. In order to overcome these limitations, We can introduce items of net sales growth ratios and industrial property-to-net asset ratios into as proxy variables of the growth and potential growth energy. In the process of analyzing these research tests, we have set three kinds of hypotheses and tested then empirically compared with KOSDAQ ordinary listing business and KOSDAQ venture businesses between long-term analysis and short-term analysis. According to the degree of concentration reflecting HHI index, our empirical research were performed in depth. Therefore, the results of this study show us that all three kinds of Hypotheses are accepted.

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GA-Enhanced Dual-Band Aperiodic Linear Dipole Array with Low Sidelobe Level (낮은 부엽 준위를 갖는 이중 대역 다이폴 배열 안테나)

  • Son, Trinh-Van;Kwon, Gina;Hwang, Keum Cheol;Park, Joon-Young;Kim, Seon-Joo;Kim, Dong-Hwan
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37C no.12
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    • pp.1296-1302
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    • 2012
  • In this research, optimization of a dual-band dipole array was performed using genetic algorithm. A non-uniform, aperture-shared linear array was configured with dipoles which resonate at 4 GHz and 9.5 GHz. The excited current distributions on dipoles were computed considering mutual coupling between dipole elements. The current distributions were also computed using method of moment (MoM). The optimization using genetic algorithm was performed to obtain the low sidelobe levels in two operating frequency band. The PSLs of the optimized array for 4 GHz and 9.5 GHz are -15.7 dB and -17 dB, respectively. Comparison between computed and simulated results are also discussed.

A Study on the Fabrication of p-type poly-Si Thin Film Transistor (TFT) Using Sequential Lateral Solidification(SLS) (SLS 공정을 이용한 p-type poly-Si TFT 제작에 관한 연구)

  • Lee, Yun-Jae;Park, Jeong-Ho;Kim, Dong-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.51 no.6
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    • pp.229-235
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    • 2002
  • This paper presents the fabrication of polycrystalline thin film transistor(TFT) using sequential lateral solidification(SLS) of amorphous silicon. The fabricated SLS TFT showed high Performance suitable for active matrix liquid crystal display(AMLCD). The SLS process involves (1) a complete melting of selected area via irradiation through a patterned mask, and (2) a precisely controlled pulse translation of the sample with respect to the mask over a distance shorter than the super lateral growth(SLG) distance so that lateral growth extended over a number of iterative steps. The SLS experiment was performed with 550$\AA$ a-Si using 308nm XeCl laser having $2\mu\textrm{m}$ width. Irradiated laser energy density is 310mJ/$\textrm{cm}^2$ and pulse duration time was 25ns. The translation distance was 0.6$\mu$m/pulse, 0.8$\mu$m/pulse respectively. As a result, a directly solidified grain was obtained. Thin film transistors (TFTs) were fabricated on the poly-Si film made by SLS process. The characteristics of fabricated SLS p -type poly-Si TFT device with 2$\mu\textrm{m}$ channel width and 2$\mu\textrm{m}$ channel length showed the mobility of 115.5$\textrm{cm}^2$/V.s, the threshold voltage of -1.78V, subthreshold slope of 0.29V/dec, $I_{off}$ current of 7$\times$10$^{-l4}$A at $V_{DS}$ =-0.1V and $I_{on}$ / $I_{off}$ ratio of 2.4$\times$10$^{7}$ at $V_{DS}$ =-0.1V. As a result, SLS TFT showed superior characteristics to conventional poly-Si TFTs with identical geometry.y.y.y.

A study on the screening of toxic materials by HPTLC and GC/MS (HPTLC 및 GC/MS를 이용한 유해화학물질의 스크리닝에 관한 연구)

  • Park, Sung-Woo;Jang, Seong-Gil;Park, You-Sin;Lee, Jin-Hoon;Lee, Sang-Ki;You, Jae-Hoon;Kim, Dong-Hwan;Jin, Kwang-Ho;Kim, Ki-Wook;Kim, Yu-Na;Lho, Dong-Seok
    • Analytical Science and Technology
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    • v.13 no.1
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    • pp.108-120
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    • 2000
  • To perform an effective screening for toxic materials of forensic interest detected in high profile criminal case in biological and environmental samples, we tried to construct a searchable computerized database using HPTLC(High Performance Thin Layer Chromatography) and GC/MS. Retardation factor($R_f$) values and UV spectral data of HPTLC were investigated for 160 pesticides, 34 chemicals and 39 explosives of standard grade. The data were compiled in a library. We also analyzed 112 pesticides, 31 chemicals and 17 explosives and 57 volatile organic compounds(VOCs) by GC/MS. The data for RT and characteristic mass ions were also compiled in a library.

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The Radiation Compensation Method for Two Dimensional Direction Finding of GPS Signal and Experiment Method (광대역 GPS신호의 2차원 방향탐지를 위한 방사보정 기법 및 시험 방안)

  • Ju, Hyung-Jun;Park, Seul-Gi;Kim, Dong-Whan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.1
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    • pp.155-162
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    • 2020
  • In this paper, we present a radiation compensation method and experiment method for two-dimensional direction finding by elevation and azimuth angles of broadband GPS signal, and then produce experimental results. Previous studies have performed direction finding by only using the azimuth angle of the detected signal. So, the compensation table utilizes compensation data by azimuth angles only. However, the presented method in this study has compensation data by azimuth and elevation angles for two-dimensional direction finding. Because of direction finding systems and applications are diversified, recently. So, we present a two-dimensional radiation compensation method. For evaluation of the presented compensation method, we calculate the ideal phase differences on the antenna for two-dimensional direction finding and simulate phase differences using a FEKO EM simulator. Subsequently, we analyze experimental data by radiation compensation experiments using the presented compensation method in an anechoic chamber.

A Case Study on the Customer Loyalty through CRM: -Focused on the Uzbekistan's Mobile Telecommunication Companies- (CRM을 통한 고객충성도에 관한 사례연구)

  • Makhkamov Mumin Sh.;Kim, Dong-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.6
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    • pp.1356-1363
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    • 2006
  • The main objective of this research is an increased understanding of how a supplier can successfully manage its care business in the mobile telecommunications market. In order to carry out this purpose, Uzbekistanis mobile telecommunication market has been studied as a case study in this research. The study tried to identify the forces and the factors present in CRM, and the role of these in enhancing (endangering) business. The objective was to gain a better understanding of how customer could be successfully managed and treated through CRM system. Processes and measures of customer satisfaction and loyalty provide two main aspects of the study. The importance of the concept of care and the actions that define it were found to be critically important for creating loyal customers. The relation between customer's needs, satisfaction, and loyalty, and how these ultimately relate to a providing firm's profitability, were seen to be linked in complex ways. The complexity can be studied in many ways but herein the customer satisfaction-loyalty of each event was first evaluated separately. Customer satisfaction and loyalty were then related to each other in order to compare the separate and combined characteristics.

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Composition Control of a Light Absorbing Layer of CuInSe2 Thin Film Solar Cells Prepared by Electrodeposition (전착법을 이용한 CuInSe2 박막태양전지 광활성층의 조성 조절)

  • Park, Young-Il;Kim, Donghwan;Seo, Kyungwon;Jeong, Jeung-Hyun;Kim, Honggon
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.3
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    • pp.232-239
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    • 2013
  • Thin light-active layers of the $CuInSe_2$ solar cell were prepared on Mo-coated sodalime glass substrates by one-step electrodeposition and post-annealing. The structure, morphology, and composition of $CuInSe_2$ film could be controlled by deposition parameters, such as the composition of metallic precursors, the concentration of complexing agents, and the temperature of post-annealing with elemental selenium. A dense and uniform Cu-poor $CuInSe_2$ film was successfully obtained in a range of parametric variation of electrodeposition with a constant voltage of -0.5 V vs. a Ag/AgCl reference electrode. The post-annealing of the film at high temperature above $500^{\circ}C$ induced crystallization of $CuInSe_2$ with well-developed grains. The KCN-treatment of the annealed $CuInSe_2$ films further induced Cu-poor $CuInSe_2$ films without secondary phases, such as $Cu_2Se$. The structure, morphology, and composition of $CuInSe_2$ films were compared with respect to the conditions of electrodeposition and post-annealing using SEM, XRD, Raman, AES and EDS analysis. And the conditions for preparing device-quality $CuInSe_2$ films by electrodeposition were proposed.

Effects of Mokhyangsaenghwa-tang and Mokhyangsaenghwa-tang plus Cervi Pantotrichum Cornu on Postpartum Recovery and Lactation (목향생화탕(木香生化湯)과 목향생화탕가녹이(木香生化湯加鹿茸)이 산후회복(産後回復) 및 유즙분비(乳汁分泌)에 미치는 영향(影響))

  • Kim, Dong Hwan;Chun, Ho Nam;Cho, Jung-Hoon;Jang, Jun-Bock;Lee, Kyung-Sub
    • The Journal of Korean Obstetrics and Gynecology
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    • v.18 no.1
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    • pp.111-127
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    • 2005
  • Objective : This study was conducted to investigate the effect of Mokhyangsaenghwa-tang (MS) and Mokhyangsaenghwa-tang plus Cervi Pantotrichum Cornu (MS-C) on postpartum recovery and lactation. Materials and Methods : We used 18-week pregnant Spraque Dawley rats and administered the decoctions of MS and MS-C to rats once a day for 4 days or 8 days. Then we observed changes in the body weight of pup rats and complete blood cell count, liver function test, renal function test, mammary gland tissue, level of serum prolactin, ${\beta}-casein$ and WAP of postpartum rats. Result : A significant increase in body weight was observed in MS-C treated pup rats compared with in MS treated group. The levels of WBC and platelet from MS group and MS-C group were decreased compared with the control group. The levels of RBC, hemoglobin and hematocrit from MS group and MS-C group showed statistically significant increases compared with the control group. The levels of protein, albumin from MS group and MS-C group were increased compared with the control group. The levels of BUN, creatinine from MS group and MS-C group did not show statistically significant changes compared with the control group. The mammary gland tissues from MS group and MS-C group showed increased angiogenesis. The levels of serum prolactin from MS group and MS-C group were increased compared with the control group. The expression of ${\beta}-casein$ and WAP genes from postpartum rats treated with MS and MS-C was increased. Conclusion : This study shows that MS and MS-C improved postpartum recovery and lactation in rats.

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The Flexural Strengths of Silicon Substrates with Various Surface Morphologies for Silicon Solar Cells (결정질 실리콘 태양전지용 실리콘 기판의 표면 미세구조에 따른 곡강도 특성)

  • Lee, Joon-Sung;Kwon, Soon-Woo;Park, Ha-Young;Kim, Young-Do;Kim, Hyeong-Jun;Lim, Hee-Jin;Yoon, Se-Wang;Kim, Dong-Hwan
    • Korean Journal of Materials Research
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    • v.19 no.1
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    • pp.18-23
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    • 2009
  • The influence of various surface morphologies on the mechanical strength of silicon substrates was investigated in this study. The yield for the solar cell industry is mainly related to the fracturing of silicon wafers during the manufacturing process. The flexural strengths of silicon substrates were influenced by the density of the pyramids as well as by the size and the rounded surface of the pyramids. To characterize and optimize the relevant texturing process in terms of mechanical stability and the fabrication yield, the mechanical properties of textured silicon substrates were investigated to optimize the size and morphology of random pyramids. Several types of silicon substrates were studied, including the planar type, a textured surface with large and small pyramids, and a textured surface with rounded pyramids. The surface morphology and a cross-section of the as-textured and fractured silicon substrates were investigated by scanning electron microscopy.