보험 경험요율산정을 위한 信賴度 推定模型 연구

강정혁,양원섭 한국경영과학회 1994 經營 科學 Vol.11 No.3

Credibility theory has provided with a useful tool for the assignment of weighting factor that reflects the credibility of the observed individual and collective experience to secure fair experience rate-making. We review credibility models which can effectively estimate risk premiums using credibility theory, and suggest an empirical Bayed model based on the collective statistics to estimate the structural parameters. To illustrate the use of evolutionary models, the models are applied to the actual data, such as loss ratio, claim frequencies and severity, in the Korean automobile insurance. Also the possibilities of generalizations and applications of empirical models are discussed.

電子式 冷暖房器 試作에 關한 硏究(Ⅰ)

姜錤文,金元燮,柳喆魯 全北大學校 1971 論文集 Vol.13 No.-

1. The purpose of this research is trying to change the using motor-started air-conditioner and refrigerator, and to play a special part in coordination to progress our Electronic civilizations and to offer the reference data for the purpose of development of nationalization on Thermo-element. It is purpose of heat-control and improve the controlling apparatus of heat-control in the industrial part. 2. Have finished the Experiment on the Electronic thermo-elment to manufacture Air-conditioner and refrigerator, truly, have researched and investigated the designed construction of the Thermo-Box through basic experiment by the Electronic cooling and heating, air cooling and water cooling, and measurement of endothermic. The Thermo-Box is assemblized by the divised components, and have tested the characteristics of the thermo-Box. 3. By the results of the basic experiment, designed construction of Thermo-Box and the experiment of their characteristics we have got the merchandised problems considered faithfully economic class.

한국판 Edinburgh Postnatal Depression Scale의 임상적 적용

김용구,허지원,김계현,오강섭,신영철 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.1

Objectives : The EPDS (Edinburgh Postnatal Depression Scale) is a lO-items self-report scale designed as a specific instmment to detect postnatal depression by Cox et al. (1987). This study was to determine the optimal cut-offpoint ofthe K-EPDS for postpartum depression in Korea. Methods : The 239 pregnant women assessed their own psychiatric features with the Korean version of the Edinburgh Postnatal Depression Scale (K.-EPDS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Rosenberg Self-Esteem Scale (RSES) and Marital Satisfaction Scale (MSS) at 6 months ofpregnancy, 1 week after delivery, and 6 weeks after delivery. Subjects above 9 points of K-EPDS at 6 week after delivery were interviewed with Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I) to confirm postpartum depression. Results : The prevalence of postpartum depression was 12.6% (30/239 pregnant women) in our study. The total scores of K-EPDS at 6 weeks after delivery were higher significantly than those of nonnal group. The score gap of K-EPDS between the depressed pregnant group and the normal pregnant group was increased after the delivery. However, there were no differences in the epidemiological characteristics and the BDI scores at 6 weeks after delivery between groups. Using the AUC (area under the curve), the optimal point to assess the postpartum depression was revealed as 6 weeks after delivery (AUC=85.8%) or 24 weeks of pregnancy (83.7%). The cut-offpoint of K-EPDS to detect postpartum depression among pregnant women was 9/10score of K-EPDS (AUC= 81.8%). Conclusion : In the K-EPDS, cut-off score of 9/10 was optimal to assess the postpartum depression, and K-EPDS at 6 weeks of delivery was more useful than any other point of time. K-EPDS administrated during pregnancy may be a useful tool to find the vulnerability on the postpartum depression.

NH₃가스 미량첨가 분위기에서의 CO-H₂혼합가스에 의한 과탄화철의 합성

정성실,정우창,강흥원,박응열,정원섭,박익민 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.11

The synthesis process of iron carbide was proceeded in two stages of reduction of hematite fines by H₂ gas, and carburization of the reduced metal by CO-H₂ gas mixture at 600℃. The surface of reduced iron was pre-treated with an addition of 0.05 vol% NH₃-Ar before carburization. The synthesized iron carbides were comprehensively explored by C/S analyzer (Low C/S determinator), Mossbauer spectroscopy, X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy at various reaction times of 5, 10, 15, 20, 25, 30, and 35 min. By addition of a small amount of NH3 gas, the super iron carbides contained 10 wt% carbon were made, and such addition stabilized iron carbides. It was found that addition of NH3 gas played a major role in the formation of iron carbide without decomposition (Fe₃C→ 3Fe+C) of iron carbides and precipitation of free carbon. From these results, we succeed in synthesis of super iron carbide, Fe_(5)C₂, with a stable single phase without Fe and Fe₃C phases. (Received August 2, 2004)

마이크로 컴퓨터를 이용한 구형탱크에서의 액위제어

오민,이태희,강원영,신창섭 연세대학교 산업기술연구소 1987 논문집 Vol.19 No.1

The liquid level control of a spherical tank, which changes nonlinearly with the variation of a setpoint, was controlled by a micro-computer using adaptive control theory and the experimentally measured gain value were compared with the theoretically calculated values and experimental results showed that the experimental gain value followed the same pattern of the theoretically calculated value according to the set point change. Also the P-I control using the adaptive control theory showed shorter control time and smaller deviation value than general P-I control.

주의력결핍-과잉운동장애의 비중추신경흥분제 치료의 최신지견

반건호,손소정,이서경,강원섭,조아랑,박진경 경희대학교 2006 慶熙醫學 Vol.22 No.1

Methylphenidate (MPH), amphetamine, and pemoline are cerebrostimulants that have been commonly prescribed for more than half century in the treatment of attention-deficit/hyperactivity disorder (ADHD). The use of such drugs, however, is often followed by untoward effects such as loss of appetite, insomnia, nausea, abdominal pain, vomiting, irritability, and etc. There are also debates about decrements in height and weight percentiles and drug dependency. Thus, in this study, we discussed new therapeutic drugs, non cerebro-stimulants, with possibly less adverse effects and more efficacies. Atomoxetine, highly selective inhibitor of the presynaptic noradrenaline transporter with little or no affinity for other neurotransmitter transporters and receptors, is a non-excitatory drug with a strong possibility to replace CNS excitatory drugs. It is also safer in relation to drug dependency since it does not affect nucleus accumbens or the striatum. Atomoxetine, therefore, can be used in patients who do not respond to the CNS excitatory drugs. Tricyclic antidepressants, imipramine and desipramine are also most extensively studied drugs as ADHD treatment modalities. They also exert inhibitory effect on the reuptake of norepinephrine. The use of these drugs in children, however, is limited because of cardiovascular effects. Bupropion is one of promising drugs in treating prepubertal children with ADHD. It is also useful for comorbid depression and conduct problems. Increasing attention is being given to a narcolepsy drug, modafinil. Modafinil acts on histamine pathway resulting in wakefulness. This effect is similar to that of neuropeptide orexin. Since the effect of modafinil is independent of catecholamine, drug dependency adverse effect is not expected. Recently, some new drugs, such as reboxetine, are reported as safe and efficacious for children with ADHD, but they need long-term safety and controlled studies.

Fe₃O₄ nanoparticles encapsulated in one-dimensional Li₄Ti₅O₁₂ nanomatrix: An extremely reversible anode for long life and high capacity Li-ion batteries

Jo, Mi Ru,Jung, Jaepyeong,Lee, Gi-Hyeok,Kim, Yunok,Song, Kyeongse,Yang, Junghoon,Chae, Ji Su,Roh, Kwang Chul,Kim, Yong-Il,Yoon, Won-Sub,Kang, Yong-Mook Elsevier 2016 Nano energy Vol.19 No.-

<P><B>Abstract</B></P> <P>Transition metal oxides are very promising electrode materials for lithium-ion batteries that operate through conversion reactions. Energy densities for conversion reactions are higher than for intercalation reactions, but most of transition metal oxides show poor cycling performance and reversibility due to the pulverization of active materials and subsequent volume changes. We here report a facile and scalable synthesis for realizing Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>-coated Fe/Fe<SUB>3</SUB>O<SUB>4</SUB> hybrid nanocomposites in the form of one-dimensional nanofibers (C@Fe-Fe<SUB>3</SUB>O<SUB>4</SUB>/Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> hybrid NFs). This is a new class of highly-reversible and safe anode material that can significantly reduce the lithium-ion diffusion length and improve strain tolerance during Li ion insertion/extraction. Its oxidation state was also impressively controlled through a carbothermal reaction during annealing. The precise oxidation state control of C@Fe-Fe<SUB>3</SUB>O<SUB>4</SUB>/Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> hybrid NFs simultaneously enabled high capacity due to the conversion reaction of Fe<SUB>3</SUB>O<SUB>4</SUB> as well as high reversibility and stability resulting from zero-strain characteristics and superb kinetics of Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>. This new electrode material appears promising for not only future energy systems but also various electronic devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> C@Fe-Fe<SUB>3</SUB>O<SUB>4</SUB>/Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> hybrid NFs showed extremely stable cyclic retention, which enabled to realize a full cell based on transition metal oxides anode for the first time. </LI> <LI> Its mechanical flexibility, electric conductivity and thermal stability were surprisingly enhanced. </LI> <LI> This enhancement was attributed to zero-strain feature of Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>, and the evolution of Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12-δ</SUB> and metallic Fe. </LI> <LI> This novel hybrid composites showed a synergistic effect thanks to high capacity of Fe<SUB>3</SUB>O<SUB>4</SUB>, high thermal and structural stability of Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>, and the improved kinetics from dexterous oxidation state and morphology control. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>An effective strategy to significantly boost the structural stability and electrochemical performance of Fe<SUB>3</SUB>O<SUB>4</SUB> nanoparticles through the embedment in Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> nanomatrix was successfully demonstrated despite its extremely irreversible conversion reaction. The resultant C@Fe-Fe<SUB>3</SUB>O<SUB>4</SUB>/Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB> hybrid NFs showed excellent mechanical flexibility and electronic conductivity that could be each assigned to high stability or zero-strain feature of Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12</SUB>, and the evolution of oxygen-deficient Li<SUB>4</SUB>Ti<SUB>5</SUB>O<SUB>12-δ</SUB> as well as metallic Fe</P> <P>[DISPLAY OMISSION]</P>

Exceptional electrochemical performance of freestanding electrospun carbon nanofiber anodes containing ultrafine SnO_<i>x</i> particles

Zhang, Biao,Yu, Yang,Huang, Zhendong,He, Yan-Bing,Jang, Donghyuk,Yoon, Won-Sub,Mai, Yiu-Wing,Kang, Feiyu,Kim, Jang-Kyo The Royal Society of Chemistry 2012 ENERGY AND ENVIRONMENTAL SCIENCE Vol.5 No.12

<P>SnO<SUB><I>x</I></SUB>–carbon nanofiber (CNF) composites are synthesized using the electrospinning technique for use as freestanding electrodes in Li-ion batteries. The electrodes made from the composites carbonized at 750 °C (SnO<SUB><I>x</I></SUB>–CNF-750) with 14.5 wt% SnO<SUB><I>x</I></SUB> deliver a remarkable capacity of 674 mA h g<SUP>−1</SUP> after 100 cycles when discharged at 0.5 A g<SUP>−1</SUP>. This result is considered the highest among those reported in the literature for anodes made from similar electrospun carbon fibers containing SnO<SUB><I>x</I></SUB> nanoparticles. An increase in carbonization temperature to 950 °C (SnO<SUB><I>x</I></SUB>–CNF-950) results in a significant reduction of the particle content in the fiber due to aggregation of Sn to form nanoparticles external to the fibers, with concomitant degradation of capacities. The presence of amorphous SnO<SUB><I>x</I></SUB> particles at the atomic scale embedded in the conductive CNFs is thought to be responsible for the exceptional electrochemical performance of the SnO<SUB><I>x</I></SUB>–CNF-750 electrodes. These ultrafine particles facilitate the reaction Sn + <I>x</I>Li<SUB>2</SUB>O → SnO<SUB><I>x</I></SUB> + 2<I>x</I>Li<SUP>+</SUP> + 2<I>x</I>e<SUP>−</SUP>, making it highly reversible, which is confirmed by the growing peak currents with increasing scan rate indicated by cyclic voltammetry, and the absence of Sn–Sn bonds in the particles revealed by the extended X-ray absorption fine structure spectroscopy (EXAFS). Both the SnO<SUB><I>x</I></SUB> particle size and content in the fiber play important roles in controlling the rate and cyclic performance of the SnO<SUB><I>x</I></SUB>–CNF composite electrodes.</P> <P>Graphic Abstract</P><P>This paper presents novel SnO<SUB><I>x</I></SUB>–carbon nanofiber composites with embedded ultrafine SnO<SUB><I>x</I></SUB> particles. The composites deliver remarkable power/energy densities as well as excellent cyclic performance due to their high reversibility and stability. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2ee23145j'> </P>

Solvent-polarity-induced hematite (α-Fe₂O₃) nanostructures for lithium-ion battery and photoelectrochemical applications

Pawar, Rajendra C.,Um, Ji Hyun,Kang, Suhee,Yoon, Won-Sub,Choe, Heeman,Lee, Caroline S. Elsevier 2017 ELECTROCHIMICA ACTA Vol.245 No.-

<P><B>Abstract</B></P> <P>A range of morphology-controlled hematite superstructures, including two-dimensional sheet assembly, microspheres with a vein-like network, hollow urchin with tapered nanorods, and flowers with porous branch-like structures, were obtained from different solvents via the solvothermal approach. The results showed that the variation of the solvent from protic to aprotic facilitated morphological modifications, with the solvent playing a key role in determining the overall architecture of the oxide particles under different polar conditions. A porous microsphere grown from water solvent delivered a reversible capacity of 880mAhg<SUP>−1</SUP> over 60 cycles at 200mAg<SUP>−1</SUP> with good rate stability. Here, the bicontinuous nanoporous structure, with well-developed mesoporosity in the microsphere, reduced the severity of volume changes during the cycling process and stabilized passivation layer growth. The hematite nanostructure grown from water/dimethylformamide solvent exhibited the highest photocurrent density of 190μA/cm<SUP>−2</SUP> vs. Ag/AgCl, which was attributed to the rapid transport of charge carriers in the porous nanostructure. Thus, solvent-mediated synthesis can be used to prepare a range of hematite porous nanostructures for use as an anode in lithium-ion batteries and as a photoanode in photoelectrochemical cells, as well as for water splitting, gas sensors, and catalytic applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Solvent polarity induced α-Fe<SUB>2</SUB>O<SUB>3</SUB> nanostructures via solvothermal method. </LI> <LI> Polar aprotic/protic solvent controls growth kinetics. </LI> <LI> Excellent lithium ion storage and photoelectrochemical properties. </LI> <LI> Mesoporus structure improves the actives sites and performances. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Cycle performance of the porous microsphere grown from H<SUB>2</SUB>O solvent at 200mAg<SUP>−1</SUP> compared to similar hematite structures from the literature with veins network (inset TEM image).</P> <P>[DISPLAY OMISSION]</P>

High rate capabilities induced by multi-phasic nanodomains in iron-substituted calcium cobaltite electrodes

Ko, Young-Dae,Kang, Jin-Gu,Choi, Kyung Jin,Park, Jae-Gwan,Ahn, Jae-Pyoung,Chung, Kyung Yoon,Nam, Kyung-Wan,Yoon, Won-Sub,Kim, Dong-Wan Royal Society of Chemistry 2009 Journal of materials chemistry Vol.19 No.13

<P>Two-dimensional (2-D) nanoplates of iron-substituted calcium cobaltite (Ca<SUB>3</SUB>Co<SUB>3</SUB>FeO<SUB>9</SUB>) are synthesized through a simple citrate-gel method. The lithium electroactivity of Ca<SUB>3</SUB>Co<SUB>3</SUB>FeO<SUB>9</SUB> demonstrates that this is an applicable active anode material. In this study, we focus on the reversible conversion process and internally multi-phasic, nanostructured character occurring in Ca<SUB>3</SUB>Co<SUB>3</SUB>FeO<SUB>9</SUB> nanoplates. Moreover, we demonstrate that in-situ formation of active/inactive nanocomposite improves the conversion reaction kinetics by accommodating the large volume changes during lithium uptake and removal, thereby achieving outstanding rate capabilities.</P> <P>Graphic Abstract</P><P>Two-dimensional nanoplates of iron-substituted calcium cobaltite (Ca<SUB>3</SUB>Co<SUB>3</SUB>FeO<SUB>9</SUB>) synthesized through a simple citrate-gel method are found to be an active anode material. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=b817120c'> </P>