편백나무의 반응 조건별 저속 열분해 생성물 특성 분석 연구

유승한,박진제,김민수,류창국,박정극 한국열환경공학회 2019 한국열환경공학회 학술대회지 Vol.2019 No.-

韓國 自動車産業의 下請生産과 그 立地에 關한 硏究

柳承翰 동국지리학회 1989 東國地理 Vol.- No.10

A firm operates its economic activity through the complex interaction with other firms. Therefore, to understand modern industrial location, it is crucial that the whole process of locational decision-making is viewed in the context of the interdependence between a firm and its external environment. In this regard, this study examined structure of production subcontracting in the Korean automobile industry, focused on Hyun Dai Motors, Crop., having an interest in spatial interaction and locational pattern of the subcontractor. The results are summarized as follows; First, there is a tendency of the aggregate locational pattern that the subcontractor is located near the parent firm's production facility. However, it is difficult to demonstrate the tendency can apply to all of subcontractors. This study cissified subcontractors into several sub-groups based on their characteristics such as natures of products, scales of subcontracting, and investigated their locational patterns. As a result, each sub-group shows its own locational pattern; subcontractors which producing by press are more closely located to parent firm's production facility than subcontractors which produce electric devices; subcontractors with intense and large subcontracting linkage in scale are more closely located to parent firm's production facility than those small in scale of subcontracting. the spatial variations are due to natures of products, scales of subcontracting, purchasing strategy of parent firm, and historical inertia of auto-parts industry. Second, from the view-point of spatial arrangement of subcontractor, Hyun Dal's subcontractors have/have been concetrated around their parent firm's production site, UlSan. To explain this tendency, four types of industrial movement-new entry, closure, transfer, and establishment of branch plant - are examined and most of spatial concentration is proved to be a consequence of the last two types of movement. Finally, in terms of locational change of subcontractors, parent firm requires subcontractors to move from Ex-UlSan to UlSan and its adjacent region. By the movent of subcontractors to the parent firm's production facility, it is possible for parent firm to minimize inventory cost and to reduce production cost. On the contrary, subcontractors regard stablization of subcontracting relationship and technological assistance from the parent firm as major and important possible advantages. Nevertheless, the obstacles of movement from firm's internal and/or external environment made most subcontractors hardly move to UlSan and its adjacent region. Most crucial factors in these obstacles are identified uncertainity of relationship with the parent firm, small in subcontracting scale, enterpreneurer's personal factors, excessive land values and labor shortage.

立地論에 있어 去來費用理論과 垂直統合에 關한 論議

柳承翰 동국지리학회 1990 東國地理 Vol.- No.11

The attempt of this study is to review transaction cost theory, and to identify its applicability to industrial geography. Transaction cost theory, elaborated by economist, Oliver Williamson following early work of Ronald coase, is an attempt to explain the origin and growth of firm by the comparative efficiency of two economic insitutions, 'market and hierarchy'. To understand vertical integration from the point of the theory, most important are three factors-bounded rationality, opportunism and asset specificity-since by the conjunction of them, classical contract is transformed into small number bargaining, which make 'market transaction' less efficient than 'internal production'. However, without any one of the three factors, the reason for vertical intergration will disappear. Like other industrial organization theories, its main emphasis is given to the firm's internal structure, and consequently, little is directly linked to spatial analysis. Nevertheless, considering spatial linkage as geographical expression of firm's market transaction, some concepts of the theory can provide valuable insights into the analysis of production system and its change. Among them, such factors as asset-specificity and opportunism are considered most useful to industrial geography. However industrial system is too complex to be analysed by only one theory, and some assumptions of the theory are far from the reality. Thus, other complementary theories are needed to explain more correctly our industrial system, and among them 'strategic behavior theory' seems to be crucial for more realistic approach to firm's behavior, though not explicitly discussed here.

연소전 조건에서 탄산칼륨계 흡수제의 이산화탄소 흡수특성

유승한,오명석,차왕석,You, Seung-Han,Oh, Myoung-Seog,Cha, Wang-Seog 한국산학기술학회 2011 한국산학기술학회논문지 Vol.12 No.2

기액 흡수평형(VLE)장치를 사용하여 연소전 조건에서 흡수용액인 $K_2CO_3$의 이산화탄소 흡수능 및 초기흡수속도를 측정하였다. 흡수실험은 온도 $40{\sim}80^{\circ}C$, 이산화탄소 압력 0~50기압 범위에서 수행되었으며, 또한 흡수용액 중 $K_2CO_3$ 농도에 따른 흡수능 변화도 조사하였으며 이때 농도변화는 5~20%이었다. 실험결과, 흡수용액 중 $K_2CO_3$ 농도가 증가할수록 이산화탄소 흡수능과 초기흡수속도는 증가하였으며, 반응온도에 따른 초기흡수속도는 $40^{\circ}C$에서 가장 높았다. $K_2CO_3$ 흡수용액의 흡수능을 증진시키기 위해 Piperazine과 homopiperazine을 각각 첨가하여 흡수 실험한 결과 Piperazine을 첨가한 경우가 이산화탄소 흡수능을 다소 증진시킴을 알 수 있었다. The absorption capacity and initial absorption rate of $CO_2$ into aqueous $K_2CO_3$ solutions were measured by using VLE(Vapor-Liquid-Equilibrium) equipment in the pre-combustion condition. Absorption experiments were conducted within the temperature range of $40{\sim}80^{\circ}C$ while increasing the $CO_2$ pressure from 0 to 50bar. The effect of $K_2CO_3$ concentration was investigated by varying in the range of 5~20%. As a results, the absorption capacity and initial absorption rate were increased with increasing $K_2CO_3$ concentration in the absorbents. Also, the initial absorption rate was highest at $40^{\circ}C$. Further more, we have studied the effect of adding piperazine and homopiperazine to $K_2CO_3$ solutions. The results showed that absorption capacity of $CO_2$ was somewhat increased by adding piperazine.

지정토론

유승한 한국금융연구원 2013 한국경제의 분석 Vol.19 No.2

본 연구는 우리나라의 소득분배지표의 근간이 되는 통계청의 가계조사방식이 가지고 있는 한계점에 대해 논의하고 소득세 자료를 이용하여 이를 보정할 수 있는 대안을 제시하고 있다. 구체적으로 살펴보면, 가계조사방식은 상위소득자 를 누락하게 되는 문제점과 더불어 누락되지 않은 표본들에서도 과소보고현상이 일관되게 나타나고 있고, 이는 우리나라의 소득불평등도를 과소평가하게 만드는 원인이 될 수 있다는 것을 다각도로 보여주고 있다. 이러한 논의의 가장 대표적 인 사례로 현재의 가계조사방식은 다른 OECD국가와 비교하여 우리나라를 소득 불평등도가 상대적으로 낮은 국가의 하나로 보여주고 있으나, 저자들은 이것이 가계조사방식이 불평등도를 과소평가한 것에 기인한다고 설명하고 있다. 흥미로운 연구로서 최근에 소득집중도와 불평등도의 장기추세를 보기 위해 소득 세자료를 이용한 일련의 중요한 연구들과 관련이 되어 있다. 소득세자료를 이용 하여 소득집중도와 불평등도의 장기추세에 새로운 시각을 제시한 논문들은 Piketty (2001, 2003)가 프랑스의 사례를 연구한 것으로부터 시작되어 Piketty and Saez (2003)의 미국의 사례, Atkinson(2005)의 영국의 사례와 Moriguchi and Saez(2008) 의 일본의 사례로 이어지고 최근에는 세계 각국의 사례를 연구하는 것으로 큰 영향력을 발휘하고 있다(Atkinson, Piketty and Saez(2011)). 본 연구는 한국의 사 례에 소득세 자료를 적용하여 우리나라 소득불평도에 대해 새로운 시각을 제시 하였을 뿐만 아니라 소득세 자료의 문제점을 보완하기 위한 보정방법을 논의한 다. 본 연구의 분석과 관련한 두 가지가 보완되거나 재검토되어야 할 점은 다음과 같다.

A Stag Hunt Game with Social Norms

유승한 한국계량경제학회 2013 계량경제학보 Vol.24 No.3

This paper studies a stag hunt game in which each player’s payoff depends on the level of social norms in a community. First, we establish conditions under which without social norms, there exists a unique equilibrium regarding the cooperation level, but with social norms, there can be multiple equilibria. Second, we provide the comparative statics analysis such that for a statics framework,the local stability of an interior equilibrium works as a sufficient condition under which the cooperation level increases as the degree of social norms increases;and for a dynamic framework, the cooperation level always increases with social norms.

The Synthesis of Polyimide with Cinnamate Groups and Its Photoalignmental Behaviors

유승한,유한성,장용규,한관영,송장근,채병훈 한국고분자학회 1997 한국고분자학회 학술대회 연구논문 초록집 Vol.1997 No.4

Traumatic Retropharyngeal Hematoma following Cervical Vascular Injury: A Case Report

유승한,이재일,이정환,김병철,하만정,최혁진 대한신경손상학회 2020 Korean Journal of Neurotrauma Vol.16 No.2

Traumatic retropharyngeal hematoma is a potentially life-threatening complication ofcervical spine injury due to possible airway obstruction. Treatment by securing airwayand subsequent conservative care is ofen adequate. However, a rapidly expanding largehematoma requires surgical evacuation. We present a case of 55-year-old man with aretropharyngeal hematoma secondary to cervical vascular injury without associated cervicalfracture. The patient was successfully treated with endovascular arterial embolization andsubsequent percutaneous drainage under fluoroscopic guidance without any sequelae

Retro-Odontoid Pseudotumor without Atlantoaxial Subluxation or Rheumatic Arthritis

유승한,최혁진,조원호,차승헌,한인호 대한신경손상학회 2016 Korean Journal of Neurotrauma Vol.12 No.2

We present a case of retro-odontoid pseudotumor (ROP) without rheumatoid arthritis (RA) or atlantoaxial subluxation (AAS). A 76-year-old woman presented with paresthesia and weakness of both lower and upper extremities. She had no laboratory or physical findings of RA. Dynamic X-ray showed no AAS and magnetic resonance imaging (MRI) showed a retro-odontoid mass compressing the spinal cord. Transdural mass debulking and biopsy were performed via minimal left suboccipital craniectomy and C1 hemilaminectomy. Two months after surgery, her symptoms were aggravated. Follow-up MRI visualized mass re-growth and spinal cord compression due to the mass and AAS. Posterior C1-2 fixation was performed without further decompression. Twelve months after posterior fixation, no symptoms were apparent and follow-up MRI showed complete resolution of the ROP with C1-2 bony fusion. The ROP with C1-2 instability might be completely resolved only C1-2 fusion without decompression. Furthermore, we speculated that osteoarthritis of C1-2 itself causes a partial tear or degradation of the transverse ligament, that induced formation of ROP.

새로운 PPV 유도체의 합성 및 형광 특성

유승한,정성재,진정일 한국고분자학회 1996 한국고분자학회 학술대회 연구논문 초록집 Vol.1996 No.10