• Title/Summary/Keyword: 이봉구

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Developmental Rate of Vitrified Porcine Oocytes and Its Application to NT Embryos Constructed by Microinjection of Fibroblast Cells into Vitrified Oocytes (돼지 동결 난포란과 이를 이용한 핵이식 배의 체외발생에 관한 연구)

  • Lee, M.-H;Lee, B.-K;Kim, S.-K
    • Journal of Embryo Transfer
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    • v.20 no.3
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    • pp.207-215
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    • 2005
  • 본 연구는 돼지 난포란의 동결보존 후 생존성과 난자의 활성화 처리에 따른 체외발생율과 이를 이용한 핵 이식배의 체외발생율을 조사하였다. 활성화 처리된 배는 $5\%$ FBS가 첨가된 NCSU 23 배양액으로 $38.5^{\circ}C$, $5\%\;CO_2$$95\%$ air의 조건으로 배양하였다. 1. 난포란을 EDS와 $5\%$ PVP로 동결 후 $10\%$ FBS가 첨가된 NCSU 23 배양액으로 $0{\~}10$시간 배양했을 때 체외발생율은 $36.0\%$로서 대조군인 비동결 난포란의 체외발생율 $46.0\%$에 비해 낮았다. 2. Ethanol과 cyclojexamide로 처리 후 42 및 46시간 배양한 배의 분할율은 각각 $33.3\%$, $36.0\%$$27.1\%$, $30.0\%$로서 대조군의 $8.8\%$, $11.4\%$에 비해 높게 나타났다. 3. 동결 및 비동결 난포란을 이용한 핵이식 배의 융합율과 발생율 간에는 유의한 차이가 없었다. 4. Ethanol과 cyclojexamide로 활성화 처리한 난자를 이용하여 재구축한 핵 이식배의 발생율은 $2.8\%$, $5.3\%$$1.5\%$, $2.9\%$로서 대조군의 $0.0\%$, $0.0\%$에 비해 높은 발생율을 나타냈다.

A study on automation of modal analysis of a spindle system of machine tools using ANSYS (ANSYS를 활용한 공작기계 주축 시스템의 진동 모드 해석 자동화에 관한 연구)

  • Lee, Bong-Gu;Choi, Jin-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.4
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    • pp.2338-2343
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    • 2015
  • An analytical model was developed in this study and then implemented into a tool for automation of FEA (Finite Element Analysis) of a spindle system for natural frequencies and modes in the universal FEA software, ANSYS. VBA of EXCEL was used for the implementation. It allowed graphic user interfaces (GUIs) to be developed for a user to interact with the tool and, in addition, an EXCEL spreadsheet to be used for data arrangement. A code was developed in the language of ANSYS to generate the geometric model of the spindle system, sequentially to construct the analytical model based on the information in the GUIs, and finally to perform computation for the FEA. Its automation of the model generation and analysis can help to identify a near optimal design of the spindle system under design in minimum time and efforts.

Differences in Corporate Crisis Management Between CEO's Leadership Styles (CEO의 리더십 유형에 따른 기업의 위기관리 차이에 관한 연구)

  • Hong, Han-Kuk;Woo, Bo-Hyun;Lee, Bong-Gu
    • The Journal of the Korea Contents Association
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    • v.13 no.9
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    • pp.382-391
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    • 2013
  • Crisis management is one of the most important tasks of any business as business environments have been dramatically changed. In a sense the ability to manage crisis effectively is connected to the survival of any organization, whether it be a nation or company. In case of a company, the ability depends on CEO's leadership styles. Though some research have internationally investigated the relationship between crisis management and CEO's leadership styles, few research has dealt with the issue. The purpose of this study was to investigate the role of CEO's leadership styles in the perception of the importance of corporate crisis management and the level of crisis management. A self-administered questionnaire was distributed to CEOs of various types of business and a total of 259 questionnaires were collected from them. But only 201 questionnaires were used for testing hypotheses after getting rid of incomplete ones. The result showed that CEO's leadership styles have different roles in the issues raised in this study. Implications and further research suggestions were discussed.

duoPIXTM X-ray Imaging Sensor Composing of Multiple Thin Film Transistors in a Pixel for Digital X-ray Detector (픽셀내 다수의 박막트랜지스터로 구성된 듀오픽스TM 엑스선 영상센서 제작)

  • Seung Ik, Jun;Bong Goo, Lee
    • Journal of the Korean Society of Radiology
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    • v.16 no.7
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    • pp.969-974
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    • 2022
  • In order to maximize dynamic range and to minimize image lag in digital X-ray imaging, diminishing residual parasitic capacitance in photodiode in pixels is critically necessary. These requirements are more specifically requested in dynamic X-ray imaging with high frame rate and low image lag for industrial 2D/3D automated X-ray inspection and medical CT imaging. This study proposes duoPIXTM X-ray imaging sensor for the first time that is composed of reset thin film transistor, readout thin film transistor and photodiode in a pixel. To verify duoPIXTM X-ray imaging sensor, designing duoPIXTM pixel and imaging sensor was executed first then X-ray imaging sensor with 105 ㎛ pixel pitch, 347 mm × 430 mm imaging area and 3300 × 4096 pixels (13.5M pixels) was fabricated and evaluated by using module tester and image viewer specifically for duoPIXTM imaging sensor.

Radiation Resistance Evaluation of Thin Film Transistors (박막트랜지스터의 방사선 내구성 평가)

  • Seung Ik Jun;Bong Goo Lee
    • Journal of the Korean Society of Radiology
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    • v.17 no.4
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    • pp.625-631
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    • 2023
  • The important requirement of industrial dynamic X-ray detector operating under high tube voltage up to 450 kVp for 24 hours and 7 days is to obtain significantly high radiation resistance. This study presents the radiation resistance characteristics of various thin film transistors (TFTs) with a-Si, poly-Si and IGZO semiconducting layers. IGZO TFT offering dozens of times higher field effect mobility than a-Si TFT was processed with highly hydrogenated plasma in between IGZO semiconducting layer and inter-layered dielectric. The hydrogenated IGZO TFT showed most sustainable radiation resistance up to 10,000Gy accumulated, thus, concluded that it is a sole switching device in X-ray imaging sensor offering dynamic X-ray imaging at high frame rate under extremely severe radiation environment such as automated X-ray inspection.

Studies on the Ultrarapid Freezing of In vitro Fertilized Bovine Embryos I. Studies on the Survival Rates after Slow and Ultrarapid Frozen -Thawing of In Vitro Fertilized Bovine Embryos (소 체외수정란의 초급속동결에 관한 연구 I. 소 체외수정란의 완만 및 초급속동결 융해후의 생존성에 관한 연구)

  • 김상근;이봉구;이규승
    • Korean Journal of Animal Reproduction
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    • v.15 no.2
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    • pp.133-139
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    • 1991
  • This stduy was carried out in order to investigate the effects of concentration and equilibration time of cryoprotective agents on survival rate of slow and ultrarapidly frozen in vitro fertilized bovine embryos. In vitro fertilized bovine embryos, following dehydration by cryoprotective agents and sucrose, were slowly freezed(from 2$0^{\circ}C$ to -7$^{\circ}C$/-1$^{\circ}C$/min., from -7$^{\circ}C$ -35$^{\circ}C$/-0.2$^{\circ}C$/min. from -35$^{\circ}C$ to -38$^{\circ}C$/-0.3$^{\circ}C$/min.) by cell freezer and directly plunged into liquid nitrogen and thawed in 38$^{\circ}C$ water. Survival rate was defined by development rate to the morula and blastocyst stage after in vitro cultured and FDA test. The results are summarized as follows : 1. The survival rates of in vitro fertilized bovine embryos after slow frozen-thawing in the freezing medium of 0.25M sucrose added 2.5M glycerol, 3.0M DMSO, 2.0M propanediol and 2.5M glycerol+2.0M propanediol were 84.3%, 85.9%, 77.8%, 74.3%, respectively. 2. The survival rates of in vitro fertilized bovine embryos after slow frozen-thawing in the freezing of 0.50M sucrose added 2.5M glycerol, 3.0M DMSO, 2.0M propanediol and 2.5M glycerol+2.0M propanediol were 83.8%, 85.1%, 71.4%, 74.6%, respectively. 3. The survival rates of in vitro fertilized bovine embryos after ultrarapid frozen-thawing in the freezing of 0.25M sucrose added 2.5M glycerol, 3.0M DMSO, 2.0M propanediol and 2.5M glycerol+3.0M propanediol were 69.3%, 70.8%, 63.2%, 67.1%, respectively. 4. The survival rates of in vitro fertilized bovine embryos after ultrarapid frozen-thawing in the freezing of 0.25M sucrose added 2.5M glycerol, 3.0M DMSO, 2.0M propanediol and 2.5M glycerol+2.0M propanediol were 69.4%, 70.1%, 62.3%, 63.5%, respectively. 5. The survival rates of in vitro fertilized bovine embryos after slow and ultrarapid fromthawing in the freezing medium of sucrose added cryoprotective agents were not significant difference between 5min. and 10min. of equilibration time.

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Improvement of Conductive Micro-pattern Fabrication using a LIFT Process (레이저 직접묘화법을 이용한 미세패턴 전도성 향상에 관한 연구)

  • Lee, Bong-Gu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.475-480
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    • 2017
  • In this paper, the conductivity of the fine pattern is improved in the insulating substrate by laser-induced forward transfer (LIFT) process. The high laser beam energy generated in conventional laser induced deposition processes induces problems such as low deposition density and oxidation of micro-patterns. These problems were improved by using a polymer coating layer for improved deposition accuracy and conductivity. Chromium and copper were used to deposit micro-patterns on silicon wafers. A multi-pulse laser beam was irradiated on a metal thin film to form a seed layer on an insulating substrate(SiO2) and electroless plating was applied on the seed layer to form a micro-pattern and structure. Irradiating the laser beam with multiple scanning method revealed that the energy of the laser beam improved the deposition density and the surface quality of the deposition layer and that the electric conductivity can be used as the microelectrode pattern. Measuring the resistivity after depositing the microelectrode by using the laser direct drawing method and electroless plating indicated that the resistivity of the microelectrode pattern was $6.4{\Omega}$, the resistance after plating was $2.6{\Omega}$, and the surface texture of the microelectrode pattern was uniformly deposited. Because the surface texture was uniform and densely deposited, the electrical conductivity was improved about three fold.

A Study on the Design of Tool Horn for Cutting Converged with Theoretical Method and FEA (이론적 방법과 유한요소해석이 융합된 커팅용 공구 혼의 설계에 관한 연구)

  • Lee, Han-Chang;Jeong, Jin-Hyuk;Park, Chung-Woo;Oh, Myung-Seok;Park, Myung-Kyu;Lee, Bong-Gu;Kim, Chang-Hwan
    • Journal of the Korea Convergence Society
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    • v.9 no.6
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    • pp.175-182
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    • 2018
  • In this study, the theoretical method and the finite element analysis were designed in parallel to fabricate basic research data on the production of tool horn for cutting machine with ultrasonic vibration energy. In order to perform high-performance ultrasonic cutting, it is necessary to vibrate only with longitudinal vibration instead of transverse vibration. In order to efficiently transmit the mechanical vibration energy, the maximum amplitude should be generated at the output portion. Therefore, the tool horn must be designed so that the excitation frequency of the oscillator and the natural frequency of the tool horn are the same. In order to design the resonance of the tool horn, there are a theoretical approach using the one-dimensional wave equation and a method of reflecting the finite element analysis result to the design model. In this study, the approximate dimensions of the tool horn are first determined through the one- Based on the results of the finite element analysis, the optimal model was selected and reflected in the final shape of the tool horn. We will use this information as the basic data of actual tool horn for cutting, and will compare the production and experimental data with the contents of this research.

Effects of Ovarian Estrus Stage of Oocytes and Supplementation of Medium with BSA, Cysteine and Myoinositol on in vitro Maturation of Canine Oocytes (난자의 회수시기, BSA, Cysteine 및 Myoinositol이 개 난자의 체외성숙에 미치는 영향)

  • Kim, Sang-Keun;Lee, Bong-Ku;Lee, Kyu-Seung
    • Korean Journal of Agricultural Science
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    • v.34 no.1
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    • pp.13-18
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    • 2007
  • This study was carried out to investigate the effects of ovarian estrus stage of oocytes and supplementation of medium with BSA, cysteine and myoinositol on in vitro maturation of canine oocytes. The in vitro maturation(IVM) rate to metaphase II (M II) stage of oocytes recovered from different stage of the reproductive cycle (inactive, follicular and luteal stage) cultured in TCM-199 media were $0.0{\pm}0.0%$, $10.0{\pm}4.1%$ and $5.7{\pm}1.6%$, respectively. The IVM rate of oocytes collected from follicular stage was significantly higher in inactive or luteal stage of oocytes. The IVM rates of oocytes recovered from different stage of the reproductive cycle cultured in TCM-199 media with 5% BSA and 0.1 mM cysteine were$0.0{\pm}0.0%$, $15.8{\pm}4.7%$, $5.6{\pm}1.5%$, respectively. The IVM rates of oocytes recovered from different stage of the reproductive cycle cultured in TCM-199 media with 5% BSA and 10 mM myoinositol were $0.0{\pm}0.0%$, $18.4{\pm}4.6%$ and $5.7{\pm}1.9%$, respectively. The IVM rate of follicular stage oocytes was significantly higher in oocytes collected from follicular stage and with cultured 5% BSA and 0.1 mM cysteine or 5% BSA and 10 mM myoinositol compared to other experimental group.

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Studies on the Effects of the Follicle Size, Hormone Supplementation, Semen Type and Capacitation Method on In Vitro Maturation and Fertilization Rate of Bovine Follicular Oocytes (난포의 크기, 호르몬의 첨가, 정액의 형태 및 수정능획득 방법 등이 소 난포란의 체외성숙 및 체외수정율에 미치는 영향에 관한 연구)

  • 김상근;이만휘;이봉구;박항균
    • Korean Journal of Animal Reproduction
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    • v.14 no.4
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    • pp.237-244
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    • 1990
  • These studies were carried out to investigate the effects of the follicles size, hormone supplementation, semen types and capacitation methods on in vitro maturation and fertilization of bovine follicular oocytes. The ovaries were obtained from slaughtered Korean Native cows. The follicular oocytes surrounded with cumulus cells were recovered by aspirating follicular fluid from the visible follicles of diameter 3~5mm. The follicular oocytes were cultured in TCM-199 medium containing hormones, FCS, ECS, BFF and MCC for 24~48hrs. in a incubator with 5% CO2 in air at 38.5$^{\circ}C$ and then matured oocytes were again cultured for 18~20hrs. with motile capacitated sperm in the TCF(Tyroide calcium-free) solution containing 200$\mu\textrm{g}$/ml of heparin. The results obtained in these experiments were summarized as follows : 1. The oocytes classified as "A, B, C, D and Degenerative" depending morphological integrity and those were 61.4%, 12.1%, 19.2%, 4.2% and 3.0% of the total oocytes recovered, respectively. The maturation and fertilization rate of the A, B, C class follicular oocytes, cultured in the TCM-199 medium supplemented with 10% FCS were 89.1%, 78.0%, 52.6% and 78.1%, 66.1%, 33.3%, respectively. 2. The average number of the follicular oocytes recovered from follicles size, 1~2mm, 3~5mm and above 5mm in dimeter were 67, 98 and 63, respectively. The maturation and fertilization rate of the follicular oocytes, cultured in the TCM-199 medium were 56.7%, 82.5%, 46.0% and 44.8%, 71.4%, 28.6%, respectively. 3. The maturation and fertilization rate of follicular oocytes, cultured in the TCM-199 medium supplemented with 5%, 10%, 15%, 20% FCS and hCG, HCG, $\beta$-estradiol were 76.0%~82.3% and 26.2%~70.0%, and those values were higher the supplementation of the hormone than the non-supplementation. 4. The fertilization and cleavage rate of the follicular oocytes, inseminated with spermatozoas of epididymis cauda, neat and frozen semen were 63.3%, 73.3%, 70.0% and 32.7%, 37.8%, 38.3, respectively. 5. The fertilization and cleavage rate of follicular oocytes, fertilized with capacitated spermatozoas by heparin, BFF and HIS methods were 70.0%, 53.8%, 34.2% and 38.3%, 23.1%, 17.1%, respectively. And the fertilization and cleavage rate were higher method of heparin than other methods.r methods.

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