벤처기업 성공요인의 중요도

송학진,박영호 동의공업대학 1999 論文集 Vol.25 No.1

This study reports the importance of success factors for high-tech ventures based on the survey of DIT Business Incubator's ventures. We classified the success factors of high-tech ventures into four major groups and inquired about K and D ventures of DIT Business Incubator. The AHP method was applied to analyze the data. The result of analysis shows that the adequate opportunities(market opportunity, technical opportunity) and the resources security(technical resources, man power resources) are very important factors for high-tech ventures' success.

Failure Cost와 Life Cycle Cost를 고려한 연속시스템에 대한 최적 장치 선택에 관한 연구

진상화,김용하,송희열,여영구,김인원 한국안전학회 2004 한국안전학회지 Vol.19 No.4

In this study, the required life cycle cost is evaluated in consideration of the equipment's availability during its life cycle. In order to meet the maximum availability required by the process, the failure cost and life cycle cost is assessed, The optimal equipment selection method is presented according to the analysis of the failure cost and life cycle cost. For the systems in which equipments are connected serially, the optimal equipments are selected by minimizing the life cycle cost and satisfying the required system availability goal. In addition, the selection methods and life cycle cost are analyzed according to the cost variation of the equipment. By using the life cycle evaluation procedure, the failure cost and maintenance cost needed during the life cycle of the equipment can be presented.

라그랑즈 정리의 역에 관하여

송영무,한상진 순천대학교 과학교육연구소 2000 科學과 敎育 Vol.8 No.-

One of the most important combinatorial results in finite group theory is the theorem of Lagrange that says the order of any subgroup divides the order of the group. The full converse to Lagrange's Theorem is not true, but there is a partial converse which holds for arbitrary finite groups. In this note, we shall try to give a sound understanding of the meaning of the converse of Lagrange's Theorem and some examples of its application.

중소건설업체 ISO 9002 인증 문제점과 대책

박영호,송학진 동의공업대학 1999 論文集 Vol.25 No.1

Over the last few years Total Quality Management(TQM) programs have been widely adapted by the Korean construction companies to improve their productivity, competitive edge, and product quality level. Many companies have been proceeding or have completed the development of quality system since 1992. However medium and small size construction companies have many difficulties due to lack of understanding, cooperation of top or related management, money and man power. In this paper the problems of the minor construction companies are picked out through the case study of D construction company in Pusan and then countermeasures which can be efficiently applied to the development and operation of quality management system are suggested to help the medium and small construction companies that want to adopt the quality management system.

Calcium phosphate 결정 성장 최적화를 위한 Ti 표면의 BaTiO_3 박막 형성에 관한 연구

조진우,양홍서,박영준,황규석,송종은,이용렬 전남대학교 치과대학 2001 구강과학 Vol.13 No.2

This study was purposed to establish an optimized manufacturing process for a negatively charged ferroelectric thin flim on titanium substrate in order to develop a new implant system having the mechanical strength and bone forming ability. Ferroelectric materials show an alignment of positive and negative charges by poling treatment. Based on this property, this study was performed with the assumption that the Ca^2+ ions would be easily attracted on negatively charged surface and the attracted cation might behave as nuclei for bone-like crystal grownth in biological solutions. In order to have an osteoinducibility by the ferroelectric thin film coating, continuous and flawless crystalline thin film should be formed with ferroelectricity, and finally should be adequately poling treated. In this study, BaTiO_3 (BTO) was selected as a ferroelectric material. Before thin film coating process, most favorable poling condition was investiged with the evaluation of the difference in calcium phosphate (Ca-P) formation in simulated body fluid (SBF). Moreover, the parameters to form an optimum thin film were studied. Dense bulk BTO disks were fabricate using cold isostatic pressing(CIP) and sintered in air at 1300℃ for 2 hours. Sintered BTO disk was polished, and he crystallinity, microstructure, and ferroelectric characteristics were evaluated using an X-ray diffraction analysis (XRD), a field emission scanning electron microscope (FE-SEM), and an Impedance analyzer. To find the optimum poling condition for the calcium phosphate crystal formation, sintered bulk BTO specimens were treated with either of following poling conditions; 1) room temperature poling treatment [ polarizing field (Ep) = 25kV/cm, at 25℃ for 2 hours], 2) under Tc medium-temperaturepoling treatment (Ep=20kV/cm, from 85˚C to 25˚C for 2 hour), and 3) above Tc high-temperature poling were immesed in simulated body fluid (SBF) for 30 days, and the formation of calcium phosphate (Ca-P) layer n the surface was evaluated. The crystallinity, microstructure, and ferroelectric characteristic of BTO thin film were evaluated withthe variation of final heat treatment. It was performed after establishing the starting substance-solvent mixing ratio, coating times, and pre-heating temperature optimal to form continuous and flawless BTO thin film adequate for having ferroelectricity. Perparation of BTO thin film was made by dipping-pyrolysis technique using metal naphthenates as starting substances. BTO thin films was spin-coated on Ti substrate by dipping-pyrolysis technique using sol obtained by mixing Ba-naphthenate and Ti-naphthenate as starting substances. Pre-firing temperature of BTO thin film was performed at 450℃ because organic-solvent ws completely volatilized without any crystal growth, and the final heat treatment was performed at 600, 700 or 800℃, respectively. The results are as follows; 1. BTO disk sintered at 1300℃ for 2 hours showed average grain size of about 1㎛ and the relative dielectric constant at 1㎑ was abut 3000∼3500. 2. After immersing the sintered bulk BTO poled at respective conditions in SBF for 30 days, Ca-P layers were present on the negatively charged surfaces. In contrary, positively charged Bto surface did not show any noticeable charge of the surface microstructure after SBF immersion. 3. In he case of poling condition 1 and 2 treated with below Tc, Ca/P ratio showed a relatively low value of 1,.2∼1.5. While, in the case of poling condition 3 treated with above Tc, Ca/P ratio was 1.5∼1.67, which is similar to that of biological apatite. This phenomenon demonstrates that poling the BTO above the temperature of Tc is preferable for the Ca-P formation. 4. For thin film BTO coastin, the starting substance was prepared by an equimolar mixing of the Ba and Ti-naphthenate. Dilution of the starting substance with toluene was most appropriate at sol : toluene ratio of 5.2:4.8 Too thin sol produced porosity in film, and too thick sol resulted cracks in the film. By repeating the coating and pre-firing procedure 15 times, homogeneous film of 0.5㎛ thickness could be fabricated, and perfomed well during the poling treatment without breakdown. 5. The heat-treatmen of the BTO thin film at 700℃ produced a homogeneous crystalline structure without heterogeneous TiO2 formation. The BTO thin film heat-treated at 600℃ showed non-crystallinity and no ferroelectricity. Treatment at 800℃ produced heterogeneous TiO2 phase in the film, which is unfavorabe for having ferroelectricity by the distortion of the perovskite structure. The relative dielectic constant at 1 ㎑ was 152 and 112 by heat-treatment at 700 and 800℃, respectively. In summary, these results demonstrated that poling the ferroelectric B_aT_iO_3 surface negatively is effective for the formation of Ca-P layer in simulated body fluids. Poling condition at a temperature cooling from above Tc down to room temperature is most effective. By optimizing the method of BTO thin film coating on metal substrate for the formation of Ca-P layer, the data of this study might be applied for the manufacture of new bioactive implant system.

프랭크 스텔라의 작품을 모티브로 한 레고 전시 공간 디자인 프로세스 연구

서민영,송윤영,정민주,이진민,신은별 숙명여자대학교 디자인연구소 2018 숙명디자인학 연구 Vol.25 No.-

본 연구는 숙명여자대학교 공간 디자인 스튜디오Ⅰ 수업에서 진행한 전시 공간 디자인 프로세스에 관한 연구로서, 디자인의 기본 요소에 대한 탐구를 바탕으로 평면회화를 통해 평면, 입체, 공간 조형까지 차원에 확장에 따른 형태적 발전에 따른 공간디자인 프로세스를 연구한다. 이를 위해 본 연구는 크게 두가지로 나뉜다. 첫째 점, 선, 면의 디자인 기본요소를 이용하여 디자인 원리에 입각해 평면 구성을 하고 이를 바탕으로 평면회화를 선택하여 입체 조형을 통해 공간의 형태를 발전시킨다. 둘째, 공간의 형태에 적합한 브랜드를 선정하였으며 이를 위한 전시 공간으로서의 기능이 적용된 공간 계획을 하였다. 그리고 프로그램, 조닝, 동선, 색채 및 재질을 계획하였다. 끝으로 본 연구는 조형적 공간 디자인의 프로세스와 전시 컨텐츠의 접목으로 향후 이와 같은 일련의 전시 공간 디자인 프로세스에서 기초적 자료로 사용될 것으로 기대한다.

冷凍冷藏倉庫 前室部 侵氣防止裝置의 適用에 關한 硏究

석호태,곽현철,송승영,송진규,이영욱 대한건축학회 2003 대한건축학회논문집 Vol.19 No.4

This study aims to evaluate the economic performance of infiltration prevention devices for the refrigerated warehouse. It is showed that the cooling loads of refrigerated warehouses is changed by assembling of infiltration prevention devices in a previous study. Space loads and cooling energy costs according to the types of the infiltration prevention devices are analyzed by the DOE-2.1E simulation. Based on the Life Cycle Costs considered the costs of initial construction, repair·replace, cooling energy and operating energy, the probability of reducing energy consumption and application of infiltration prevent devices in vestibule of refrigerated warehouse is founded.

賣出額과 原價要素와의 相關分析

李相道,崔震永,宋瑞日 동아대학교 공과대학 부설 한국자원개발연구소 1975 硏究報告 Vol.1 No.1

This study is established upon the model on the result of correlation analysis between the sales and the cost elements(material cost, labor cost, expense cost, general administrative and selling cost) by Composite Profit and Loss Statement, and Composite Manufacturing Costs Statement of years(1962~1974), for the purpose of the main manufacturing of our country be correspondent with industrial fluctuation changing suddenly. The result is summarized as follows: 1) The ratio of cost formation in the all enterprises manufacturing is obtained for the sales(100%) as follows: ① Material Cost; 65.91% ② Labor Cost; 6.34% ③ Expense Cost; 10.25% ④ General Administrative and Selling Cost; 10.63% 2) The models are obtained as follows The correlation between the sales and the cost elements in the all enterprises manufacturing; S_(α)= 1.422M_(α)+5050.726 S_(α)=17.349 L_(α)-8056.210 S_(α)=10.096 E_(α)-2839.643 S_(α)=10.433 G_(α)-8787.845 The models of the above statements of rather scientific than the foundational data to the management policy of the main manufacturing of our country, that is the cost down, the production plan and control, the budgetary control and formation, etc., in order to achieve the management rationalization of enterprises and the elevation of productivity. At the same time the models are contributed to the establishment for the various commerce and industry of our country.

진균성 부비동염의 임상적 고찰

이승원,김장욱,박영진,송태현,이병돈,장혁순 순천향의학연구소;Soonchunhyang Medical Research Institute 2000 Journal of Soonchunhyang Medical Science Vol.6 No.1

The fungal sinusitis is relatively rare and mainly develops in immunocompromised hosts, but is sporadically appears in the immunocompetent patients, where its incidence tends to be increasing. Because the clinical features of this disease are similar to those of chronic suppurative sinusitis, this entity may be overlooked. We analysed thirteen fungal sinusitis from January 1997 through December 1999 based on clinical features, laboratory characteristics and operative findings. The results are as follows. 1)Fungal sinusitis occurred 3.3 times as frequently in female patients as in male patients and the peak age groups are 4th and 5th decades. 2) The time intervals between the onset of symptoms and the first hospital visit were as follows: 5 cases within 3 months, 1 case between 4 and 6 months, 3 cases between 7 and 12 months, and 4 cases over 1 year. 3) The chief complaints were nasal obstruction, postnasal drip, rhinorrhea, cheek pain, headache, ocular pain, sneezing. 4) The characteristic computerized tomographic findings were hyperattenuated lesions in the maxillary sinus and in the nasal cavity near the natural ostium. 5) The most common pathogen was Aspergillus(92.3%) 6) We performed Caldwell-Luc's operation only in 4 cases, Caldwell-Luc's operation with intranasal ethmoidectomy in 3 cases, Caldwell-Luc's operation with endoscopic sinus surgery in 3 cases and endoscopic sinus sugery only in 3 cases. 7) Most of the gross specimens revealed a fungus ball containing a black-brown necrotic debris or caseous material.

Significance of ferroelectric polarization in poly (vinylidene difluoride) binder for high-rate Li-ion diffusion

Song, Woo-Jin,Joo, Se Hun,Kim, Do Hyeong,Hwang, Chihyun,Jung, Gwan Yeong,Bae, Sohyeon,Son, Yeonguk,Cho, Jaephil,Song, Hyun-Kon,Kwak, Sang Kyu,Park, Soojin,Kang, Seok Ju Elsevier 2017 Nano energy Vol.32 No.-

<P><B>Abstract</B></P> <P>An interesting and effective route for improving battery performance using ferroelectric poly(vinylidene difluoride) (PVDF) polymer as a binder material is demonstrated in this work. A ferroelectric PVDF phase developed under the appropriate thermal annealing process enables generation of suitable polarization on active materials during the discharge and charge process, giving rise to longer capacity with lower overpotential at a high current rate. Electrochemical analysis including <I>in situ</I> galvanostatic electrochemical impedance spectroscopy and a galvanostatic intermittent titration measurement revealed that the ferroelectric binder effectively reduced Li-ion diffusion resistance and supported fast migration in the vicinity of active electrodes. Computational results further support that the binding affinity of the ferroelectric PVDF surface is much higher than that of the paraelectric PVDF, confirmed by ideally formed ferroelectric and paraelectric PVDF conformations with Li-ions. Furthermore, we consistently achieved high Li-ion battery (LIB) performance in full cell architecture consisting of a LTO/separator/LFP with a ferroelectric PVDF binder in the anode and cathode materials, revealing that the polarization field is important for fabricating high-performance LIBs, potentially opening a new design concept for binder materials.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The ferroelectric polarization in PVDF binder enhances Li-ions diffusion. </LI> <LI> Excellent rate performance is demonstrated by β-phase of PVDF binder </LI> <LI> In depth computational study exhibits the polarization effect of ferroelectric binder in LIB cell. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>We demonstrate the effect of PVDF polarization in lithium ion battery system. The strong polarization of ferroelectric PVDF binder on the active material enhances the transport of Li-ion during charge and discharge. As results, the Li-ion diffusion by ferroelectric phase leads to excellent rate performance and cycling stability compared to paraelectric PVDF binder.</P> <P>[DISPLAY OMISSION]</P>