비방사적 맘퀴스트 지수에 의한 총요소생산성 변화와 결정요인 분석: 전북지역전략산업을 중심으로

소순후 ( Soon Hu So ),고민창 ( Min Chang Ko ) 한국경영공학회 2015 한국경영공학회지 Vol.20 No.1

In this paper, we analyses the total factor productivity change and its determinants in Jeonbuk``s regional strategic industry during the period of 2001-2010. The paper follows a two-stage procedure. In the first-stage, using the non-radial and non-oriented Malmquist productivity index, the total factor productivity change is measured and decomposed into technical efficiency and technological change components. In the second-stage, we use fixed and random effects panel models to analyze the determinants of total factor productivity change. The empirical findings suggest that Jeonbuk``s regional strategic industry has exhibited total factor productivity growth mainly attributed to the technological progress rather than the improvement in efficiency. This implies that Jeonbuk``s regional strategic industry still needs to further strengthen technological innovation and improve production efficiency simultaneously. The findings also suggest that the determinants of total factor productivity change are industry specific, which implies that some of the determinants exert different influences across industries. From the findings of the current study, it is proposed that future studies should include other relevant variables which best explain productivity changes.

Correlating Structural Changes and Gas Evolution during the Thermal Decomposition of Charged Li_<i>x</i>Ni_0.8Co_0.15Al_0.05O₂ Cathode Materials

Bak, Seong-Min,Nam, Kyung-Wan,Chang, Wonyoung,Yu, Xiqian,Hu, Enyuan,Hwang, Sooyeon,Stach, Eric A.,Kim, Kwang-Bum,Chung, Kyung Yoon,Yang, Xiao-Qing American Chemical Society 2013 Chemistry of materials Vol.25 No.3

<P>In this work, we present results from the application of a new in situ technique that combines time-resolved synchrotron X-ray diffraction and mass spectroscopy. We exploit this approach to provide direct correlation between structural changes and the evolution of gas that occurs during the thermal decomposition of (over)charged cathode materials used in lithium-ion batteries. Results from charged Li<SUB><I>x</I></SUB>Ni<SUB>0.8</SUB>Co<SUB>0.15</SUB>Al<SUB>0.05</SUB>O<SUB>2</SUB> cathode materials indicate that the evolution of both O<SUB>2</SUB> and CO<SUB>2</SUB> gases are strongly related to phase transitions that occur during thermal decomposition, specifically from the layered structure (space group <I>R</I>3̅<I>m</I>) to the disordered spinel structure (<I>Fd</I>3̅<I>m</I>), and finally to the rock-salt structure (<I>Fm</I>3̅<I>m</I>). The state of charge also significantly affects both the structural changes and the evolution of oxygen as the temperature increases: the more extensive the charge, the lower the temperature of the phase transitions and the larger the oxygen release. Ex situ X-ray absorption spectroscopy (XAS) and in situ transmission electron microscopy (TEM) are also utilized to investigate the local structural and valence state changes in Ni and Co ions, and to characterize microscopic morphology changes. The combination of these advanced tools provides a unique approach to study fundamental aspects of the dynamic physical and chemical changes that occur during thermal decomposition of charged cathode materials in a systematic way.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2013/cmatex.2013.25.issue-3/cm303096e/production/images/medium/cm-2012-03096e_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm303096e'>ACS Electronic Supporting Info</A></P>

흰쥐에 對한 Phosphamidon 및 Endosulfan의 亞急性毒性에 關한 硏究

申鎭燮,崔承允,李昌業,崔仁厚 서울大學校 農科大學 1984 서울대농학연구지 Vol.9 No.2

Subacute toxicity tests of phosphamidon and endosulfan were carried out to examine the adverse effects resulting from repeated daily oral administration of low dose levels (1, 2 and 5 mg/kg/day) to rats for 28 days. The results were summarized as follows: 1. Rats showed clinical signs of salivation hyperactivity, ataxia at 2mg/kg/day dosage of phosphamidon and, in addition, lachrymation, tremor, exophthalmus and diarrhea at the highest level. On the other hand, endosulfan caused only hyperactivity in rats treated with the highest dosage. There was no mortality at any dosage of either pesticide. 2. Rats gained significantly lower body weight, when treated at the 5mg/kg/day dose levels of phosphamidon and endosulfan, in comparison to normal, nontreated rats. 3. Plasma cholinesterase activity was significantly depressed at all levels of phosphamidon during the administration period, but returned to normal within 2 weeks after the last administration. Endosulfan did not change plasma cholinesterase activity at any levels. 4. Leukopenia was detected only in rats treated with phosphamidon at 5mg/kg/day level. No other adverse changes in hematology were observed in rats treated either with phosphamidon at lower levels or with endosulfan at any levels. 5. Cloudy swelling of liver was the only histological change in rats treated with phosphamidon or endosulfan at the highest level. No other histopathological change in rats treated with phosphamidon or endosulfan at the highest level. No other histopathological symptoms were found in spleen, heart, kidney, and bone marrow of rats treated. 6. It may be concluded from the results above that the "no effect level" is 1 mg/kg/day and 2 mg/kg/day for phosphamidon and endosulfan, respectively.

제주도의 대기오염 현황 및 장래예측

허철구,이기호,강창희 제주대학교 환경연구소 1993 환경연구논문집 : 제주대 Vol.1 No.-

This study deals with the air pollution status, the characteristics of air pollution sources and the prediction of future air quality in Cheju. The present air quality is estimated very satisfactorily in comparison with the air quality standard. And the concentration of sulfur dioxide in ambient air has been increased little for the last five years. The primary major source of air pollution is transportation which include 57% of total emissions of air pollutants. Also. air pollution sources are rnaldistributed on the seashore, especially concentrated on Cheju city, The emission rate of air pollutants in Cheju is 43,766 ton/year. but emissions per uint area (24ton/year. ㎢) is of very small quantity in comparison with that of other region. On the other hand, the ambient air quality a t the year 2001 is predicted by Val-ley model is lower than the air quality standard, althought emission rate is increased due to increasing in air pollution sources.

해안지역 강수와 부유분진의 화학적 조성 비교

허철구,강창희 제주대학교 환경연구소 1994 환경연구논문집 : 제주대 Vol.2 No.1

This study was carried out to investigate the chemical composition of rainwater and atmospheric total suspended particulates (TSP) at coastal area. For this study, the rain-water and TSP were sampled a t Cheju-Kosan near the sea from May to December 1993, and then major water soluble ionic species(WSl) in those were analyzed. The concentrations of WSI in rainwater and TSP were lower than inland regions and had larger variation for each ion species. The sum of cation concentrations (166.4±336.7μeq/ℓ) were slightly greater than the sum of anion concentrations (163.2±249.5μeq/ℓ) in rainwater, but the sum of cation concentrations (0.157±0.056μeq/㎥) were considerably less than the sum of anion concentrations (0.188±0.0077μeq/㎥). The ion concentrations in rainwater were correlated negatively with precipitation, on the other hand those in TSP were correlated positively with wind velocity and had little correlation with precipitation. The ionic composition of rainwater, that is, Na^(-)>Mg^(2+)>Ca^(2+)>NH4_(4)^(-)>K^(+) for cation and Cl^(-)> S0_(4)^(2-)>NO_(3)^(-) for anion in order of abundance, showed different trend from the general trend in inland areas, however, that of TSP was similar to the general trend. The primary sources of Na^(+), Mg^(2+) and Cl^(-) were found to be seasalt and SO_(4)^(2-) and NH_(4)^(+) probably originated mainly from soil dust, while NO_(3)^(-) was possibly derived from various origins. And the contribution of seasalt to WSI in rainwater and TSP were about 70% and 37%. respectively. In addition, the average washout factor by rain fall for WSI was evaluated to 1.019 and the wet deposition rate of WSI was estimated at 10.65 ton/㎢/year.

제주시 지역 대기분진의 화학적 조성 연구

강창희,허철구 濟州大學校 基礎科學硏究所 1992 基礎科學硏究 Vol.5 No.1

The monitorings of airborne particulates were performed at three sites in Cheju Do, that is Cheju city, Kosan and Onpyung area. In order to evaluate the air pollution level, the collected airborne particulates were analyzed for some aquatic ions and metal components by ion chromatographic method and inductively coupled plasma spectrophotometry. From the results of chemical analysis, it was found that the atmosphere of Cheju city was a little bit more polluted than that of Kosan and Onpyung area. Especially for SO₄²-, NO₃-, Pb, Fe components, Cheju city showed higher concentrations than other two places. Whereas in comparison with Seoul and Pohang city, which are highly polutted places, Cheju city showed lower concentrations for the most components than those places, and especially much lower for SO₄²-, Pb, Fe components.

한국인 얼굴 연조직의 두께

김창헌,허경석,김희진,강민규,정인혁 大韓法醫學會 1999 대한법의학회지 Vol.23 No.2

제주도 연안해역을 중심으로 한 DMS 농도의 관측

강창희,허철구,이강웅,김기현 濟州大學校 基礎科學硏究所 1997 基礎科學硏究 Vol.10 No.1

The concentrations of dimethylsulfide (DMS) were determined using samples collected from a station located at Kosan, Cheju Island during two field campaigns held in December 1996 and January 1997. The atmospheric DMS concentrations measured at 6-hr intervals during the entire campaign periods, after excluding a few extreme values, spanned in the range of 14 to 410 pptv with mean and 1 SD value of 127±94 pptv (N=42). Between two month periods during which the field campaigns were conducted, a notable reduction in DMS levels was observed which was comparable to the dramatic shift in air temperature. A considerable difference was also noted in DMS levels, when data were grouped by day/night basis. The cause of unexpected, high day-to-night DMS ratios is best explained in terms of high efficiency of daytime source processes relative to low efficiency of nighttime sink processes due to the characteristics of the study location. The surface water DMS of the study site, although scarcely measure, also behaved similarly to its atmospheric counterpart with its range from 0.3 to 19 nM (N=11). When correlation analysis was conducted between the atmospheric DMS concentration and other concurrently determined parameters, significant correlations were observed from most basic meteorological parameters such as windspeed, relative humidy, and air temperature. However, the existence of "not-so-strong" correlations between air temperature and DMS concentrations relative to other ones indicated that the effect of temperature on DMS behavior must be reflected in more complicated manners at the study site. The sea-to-air flux of DMS was approximated through an application of the mass-balance flux calculation method of Wylie and de Mora(1996) under the assumption that sink mechanism within the marine boundary layer is in steady-state condition with its counterpart, source mechanism. Based on this estimation method, we reached a conclusion that oceanic DMS emitted from the southwest sea of the Korean Peninsula can amount to approximately 9~36GgSyr-1.

양이온 고분자전해질의 수중 입자의 응집에 미치는 교반강도 및 주입량의 영향

감상규,문창성,김대경,고병철,허철구 濟州大學校 海洋硏究所 2002 해양과환경연구소 연구논문집 Vol.26 No.-

Using several cationic polyelectrolytes of different charge density and molecular weight as flocculants and a simple continuous optical technique(photometric dispersion analyzer, PDA), the effects of mixing intensity and polyelectrolyte dosage on flocculation of kaoline particles(35 NTU) and particles(34.7 NTU) in Kangjung reversior of heavy rainfall have been examined. The optimum mixing was obtained at the stirring of 200rpm(G= 869 s^-1). The charge density of a polyelectrolyte is important in determining the optimum dosage and in the removl of particles. The optimum dosage is less for the polyelectrolyte of higher charge density and at the dosage, the removal of particles is higher for the polyelectrolyte of higher charge density and zeta potential of particles reaches to near zero. The optimum dosage for the removal of particles should be determined by flocculation test and not be determined by the turbidity of particles in water.

제주마의 체형에 관한 연구

강민수,정창조,강태숙,박희석,김동후,정재준 제주대학교 농과대학 제주도축산문제연구소 1986 畜産論叢 Vol.1 No.1