• 한국지역지리학회지
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• 제18권3호
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• pp.283-297
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• 2012

본 연구의 목적은 클러스터 생애주기 분석을 기반으로 서울디지털산업단지의 진화 경로와 역동성을 분석하는 것이다. 1960년대 중반부터 1990년대 후반까지 업체수와 고용자수 변화를 중심으로 구로공단의 발생-성장-유지-쇠퇴의 생애주기를 구분하고 시기별 특성을 분석하였다. 1990년대 후반 이후 업체수와 고용자수가 급증하였고, 소규모 기술집약 중소기업과 지식기반 서비스기업이 서울디지털산업단지의 성장과 구조재편을 주도하였다. 이것은 지식산업센터(아파트형공장) 증가로 가능했으며, 2000년대 중반 이후에는 지식기반 클러스터로의 변환의 생애주기 모습을 보여준다.

• Clinical and Experimental Reproductive Medicine
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• 제38권3호
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• pp.159-163
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• 2011

Objective: To compare the IVF outcomes of mild ovarian stimulation with conventional ovarian stimulation in poor responders. Methods: From 2004 to 2009, 389 IVF cycles in 285 women showed poor responses (defined as either a basal FSH level ${\geq}$12 mIU/mL, or the number of retrieved oocytes ${\leq}$3, or serum $E_2$ level on hCG day <500 pg/mL) were analyzed, retrospectively. In total, 119 cycles with mild ovarian stimulation (m-IVF) and 270 cycles with conventional ovarian stimulation (c-IVF) were included. Both groups were divided based on their age, into groups over and under 37 years old. Results: The m-IVF group was lower than the c-IVF group in the duration of stimulation, total doses of gonadotropins used, serum $E_2$ level on hCG day, the number of retrieved oocytes, and the number of mature oocytes. However, there was no significant difference in the number of good embryos, the number of transferred embryos, the cancellation rate, or the clinical pregnancy rate. In the m-IVF group over 37 years old, the clinical pregnancy rate and live birth rate were higher when compared with the c-IVF group, but this result was not statistically significant. Conclusion: In poor responder groups, mild ovarian stimulation is more cost effective and patient friendly than conventional IVF. Therefore, we suggest that mild ovarian stimulation could be considered for poor responders over 37 years old.

• 자동차안전학회지
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• 제12권3호
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• pp.52-60
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• 2020

Usage of EDR(Event Data Recorder) report for traffic accident analysis is currently increasing due to government regulation of EDR data release. Nevertheless, a lot of investigators simply adopt by comparing the number of ignition cycles(crash) at event to the number of ignition cycles(download) without an exact judgment whether event data occurred by this accident or not. In the EDR report, besides ignition cycles, there are many factors such as event record type, algorithm active(rear/rollover/side/frontal), time between events, event severity status(rollover/rear/right side/reft side/frontal), belt switch circuit status, driver/passenger pretensioner/air-bag deployment, PDOF(Principal Direction of Force) by ΔV to be able to decide whether or not to adopt. also the event data is considered enough to vehicle damaged state, accident situation at the scene of the accident. and there is described in "all data should be examined in conjunction with other available physical evidence from the vehicle and scene" in the CDR(Crash Data Retrieval) report. Therefore many investigators have to decide whether or not to adopt after they consider sufficiently to above factors when they are the traffic accident analysis and investigate the causes of a accident on the adopted event data. In this paper, we report to traffic accident investigators notable points and analysis methods on the basis of thousands of cases and the results of one's own experiment in NFS(National Forensic Service).

• 한국지반공학회지:지반
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• 제11권1호
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• pp.101-112
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• 1995

동적하중을 받는 지반-구조물 시스템의 설계를 위해 전단탄성계수와 감쇠비로 표현되는 지반의 변형특성의 결정은 매우 중요하다. 본 논문에서는 공진주/비틂전단시험기를 이용하여 저변형률 및 중간 변형률하에서 건조사질토의 변형특성을 연구하였다. 동적시험인 공진주시험과 반복시험인 비틀전단시험을 동일한 공시 체를 이용하여 실시하였다. 진동측정시스템을 개량하여 응력 -변형관계가 하중반복회수와 전단변형률의 크기에 영향을 받지않는 선형영역을 찾았으며 이 영역에서 이력감쇠가 존재함을 나타내었다. 반복한계변형률 이상에서는 하중반복회수에 따라 전단탄성계수는 증가하고 감쇠비는 감소하였다. 사질토의 전단탄성계수와 감쇠비는 진동주파수에 영향을 받지 않으며 의사정적시험인 비틈전단시험에서 변형특성과 동적시험인 공진주 시험에서 얻은 값은 비교시 하중반복회수의 영향을 고려하면 동일하다. 그러므로 공진주l비틀전단시 험을 통해 얻은 변형특성은 지반-구조물시스템의 동적해석은 물론 정적해석에서도 적용할 수 있다.

• Journal of Biosystems Engineering
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• 제21권1호
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• pp.84-93
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• 1996

Several paraffins(CnH2n +2) can be used as the thermal energy storage medium because of their large amount of latent heat and their flexibility of phase change temperature. But they have not been used in the thermal energy storage system because their long term stability have not been verified. Paraffins(CnH2n+2) which the values of n are 23, 24, 26 and 28 were selected for this experimental research. And this research was peformed to apply them to the practical systems. The results were summarized as follows. (1) The increase of phase change cycles had no effect on their phase change temperatures. (2) According as the values of n increased from 23 to 28, the specific heats of paraffins(CnH2n+2) increased, and were in the range of 0.47 0.75 ㎉/$kg^circ C$. (3) Thermal conductivities of them were in the range of 0.14 0.17 W/$m^circ C$. and specific gravities of them were in the range of 765800 kg/m3. (4) The density of paraffins was in the range of 765 800 kg/$m^circ C$ , and the density of solid phase was larger than that of liquid phase. (5) When the number of phase change cycles was 1, 500 cycles, the latent heat of paraffins was 90% of the initial value.

• The Journal of Asian Finance, Economics and Business
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• 제7권12호
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• pp.863-867
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• 2020

This study was conducted on financial data of 38 economic groups listed on Vietnam's stock market for the period 2009 - 2019 and it aims to provide an empirical evidence on the impact of working capital management policy on performance in all phases of the economic cycle of Vietnamese economic groups. The study uses FGLS estimation method with 2 dependent variables ROA, GOP, independent variables including INV, AR, AP, CCC, dummy variable representing different phases of the economic cycle, variables Control includes CAT, CR, LEV, SZ, GR. Research shows that the greater the level of investment by companies in liquid assets corresponding to a certain level of activity (shown by average days of inventory (INV), average days of collection. (AR), cash flow cycle (CCC)) the lower the rate of return on assets. The study also provides additional evidence of the negative effects of economic crisis on the performance of economic groups. The study also shows that the number of short-term asset cycles has a positive impact on operational efficiency, and the level of debt use has a negative impact on operational efficiency. This result implies that the managers of economic groups can increase the efficiency of businesses through a reasonable working capital policy.

• 대한수의학회지
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• 제34권4호
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• pp.873-880
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• 1994

Progesterone catabolizing enzyme, the enzyme $20{\alpha}$-hydroxysteroid deltydrgenase($20{\alpha}$-HSD) is pivotal in the regulation of ovarian function in rodents, which catabolizes progesterone into biologically inactive $20{\alpha}$ hydroxypregn-4-en-3-one($20{\alpha}$-OHP). In this study was carried out the influence of $20{\alpha}$-HSD activity to ovarian function and regulation such as ovulation, formation of corpus luteum, maintenance of estrous cycles and pregnancy, we investigated changes in activities of the splenic macrophages and ovarian histological findings in rat. During the estrous cycles, the ratious of phagocytotic macrophage in splenic adherent cells were highest on the proestrous, but they were lowest on metestrous. During the pregnancy, the ratious of phagocytotic macrophages in splenic adhrent cells were lowest by 1 day and then significantly increased toward the pregnancy, which were highest pregnancy on day 12. On histological findings in rat ovary, the mean number of growing, antral and mature follicles were 15.9(72.9%), 3.4(15.9%), and 2.4(11.2%), respectively. Growing follicles reached to lowest number at diestrus and mature follicle reached to lowest number at metestrus. The numbers of corpus luteums per tissue section of the ovary were 14.4 and the number of normal and atretic follicles were 11.0(76.4%) and 3.4(23.6%), respectively. The number of corpus luteum with vacolated cell were 1.7(11.8%). In this study suggests splenic macrophages are as a source of the substance which maintainer progesterone secretion from luteal cells, and are recognized pass the vessels and reside in the fresh corpora lutea soon after ovulation via inflammatory reactions, and these macrophages are felt to have a stimulatory effect on the formation of cropora lutea. In view of the results include previous report, ovarian $20{\alpha}$-hydroxysteroid dehydrogenase enzyme and splenic macrophages consider play central role in the control and maintenance of estrous cycles and pregnancy, and also applicable to both clinical and research in a wide variety such as control of reproductive system.

• 대한간호학회지
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• 제39권3호
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• pp.433-445
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• 2009

Purpose: The purpose of this study was to assess changes in pain, fatigue, anorexia, anxiety and quality of life(QOL) in patients with cancer who were on chemotherapy. Methods: Symptoms and QOL were examined both before chemotherapy and after 2 cycles of chemotherapy. The participants were 76 cancer patients receiving chemotherapy in one of 7 hospitals. Results: The patients experienced a mean of 2.22-2.23 symptoms out of 4 symptoms. Patients who were female, or suffered from breast or colorectal cancer experienced more symptoms. Fatigue at present, and most severe fatigue and anorexia in the previous 3 weeks increased significantly. Anxiety and QOL decreased significantly after 2 cycles of chemotherapy. Number of symptoms, anorexia at present, most severe anorexia in past 3 weeks, and anxiety had negative correlations. QOL before chemotherapy showed a positive correlation with QOL after 2 cycles of chemotherapy. In a regression analysis, anxiety, QOL at baseline, income, and the most severe pain in the past 3 weeks were significant predictors of QOL. Conclusion: Physical and psychological factors were significant predictors of both QOL and each subscale, and these factors correlated with each other. These results demonstrate the needs for early assessment and intervention from the start of chemotherapy to decrease symptoms and improve QOL.

• 한국해양공학회지
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• 제6권2호
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• pp.85-93
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• 1992

The only hardness of 2nd phase of martensite in dual phase steel which was composed of the martensite and ferrite was changed. Fatigue test was conducted by cantilever type of self-made rotated bending fatigue testing machine. The corrosion fatigue fracture behaviors of dual phase steel were investigated in 3% NaCl solution at $N_f$ = $1.5\times$$10^5$ $N_f$=1.0 $\times$ $10^6$ cycles. The fatigue strength was increased with increasing the hardness of 2nd phase. The size and number of corrsion pits were influenced by the 2nd phase hardness and pits remain constant in size just after they were transited into cracks. The life of crack initiation was effected by stress level. The shape of relation of $\Delta$K and da/dn has smaller scattering in it in 3% NaCl solution than that in air. The higher the 2nd phase hardness is, the higher the corrosion fatigue life becomes. Corrosion fatigue fracture behavior was effected by mechanics in case of $N_f$=1.5$\times$10$^5$$N_f$=1.5$\times$10$^6$ cycles.

• 한국표면공학회지
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• 제52권3호
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• pp.130-137
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• 2019

In this study, the cobalt sulfide (CoS) nanosheet on stainless steel as a supercapacitor electrode is synthesized by using a facile successive ionic layer adsorption reaction (SILAR) method. The number of cycles for dipping and rinsing can control the nanosheet thickness of CoS on stainless steel. Field emission-scanning electron microscopy (FE-SEM) showed a layer structure of CoS particles coupled as agglomeration. And x-ray diffraction (XRD) showed the crystallinity of the CoS nanosheet. To investigate the characteristics of the CoS nanosheet electrode as the supercapacitor, analysis of electrochemical measurement was conducted. Finally, the CoS nanosheet of 70cycles on stainless steel shows the specific capacitance ($44.25mF/cm^2$ at $0.25mA/cm^2$) with electrochemical stability of 78.5% over during 2000cycles.