기술적(技術的) 효율성(效率性)의 결정요인(決定要因)과 동태적(動態的) 변화(變化)

유승민,Yoo, Seong-min 한국개발연구원 1990 韓國 開發 硏究 Vol.12 No.4

본 논문은 유승민(劉承旻) 이인찬(李仁燦)(1990)이 추정한 우리나라 제조업(製造業)의 기술적(技術的) 효율성(效率性)을 토대로 기술적(技術的) 효율성(效率性)의 산업적(産業的) 격차(隔差)를 설명하는 경험적 증거를 구하고 효율성 추정치의 동태적(動態的) 안정성(安定性)을 분석하였다. 분석결과 산업(産業)의 생산규모(生産規模)가 클수록, 생산특화도(生産特化度)가 높을수록, 자본(資本)-노동비율(勞動比率)의 이질성(異質性)이 낮을수록 높은 기술적(技術的) 효율성(效率性)을 나타내었다. 이러한 결과는 미국(美國) 일본(日本)의 경우에 대한 연구결과와 공통되는 것으로서 기술적(技術的) 효율성(效率性)과 산업조직특성간(産業組織特性間)의 관계가 경제규모나 발전단계의 차이에도 불구하고 가설(假說)의 일반성(一般性)을 지지한다는 점에서 중요한 의미를 지닌다. 기업집중률(企業集中率) 또한 기술적 효율성에 대하여 선형(線型)보다는 이차형(二次型)의 관계를 가지고 있으나 우리나라의 경우 기술적 효율성이 극대화되는 집중률(集中率)은 매우 높은 것으로 나타났다. 또한 본 논문은 효율성(效率性) 척도간(尺度間)의 선택문제에 대한 경험적 기준을 제시하였는데 부가가치액기준(附加價値額基準)보다는 생산액기준(生産額基準)으로 추정된 기술적(技術的) 효율성(效率性)이 제가설(諸假說)들과 잘 부합되는 결과를 나타내었다. 효율성의 동태적(動態的) 안정성(安定性)에 관한 시론적(試論的) 분석(分析)에 의하면 시간변화에 따른 효율성 추청치의 안정성은 효율성 척도간에 다소의 차이는 있으나 기대한 만큼 높지 않았다. 따라서 기술적 효율성의 동태적(動態的) 불안전요인(不安全要因)에 관한 설명은 연구과제로 남는다. This paper, a sequel to Yoo and Lee (1990), attempts to investigate the interindustry determinants of technical efficiency in Korea's manufacturing industries, and also to conduct an exploratory analysis on the stability of technical efficiency over time. The hypotheses set forth in this paper are most found in the existing literature on technical efficiency. They are, however, revised and shed a new light upon, whenever possible, to accommodate any Korea-specific conditions. The set of regressors used in the cross-sectional analysis are chosen and the hypotheses are posed in such a way that our result can be made comparable to those of similar studies conducted for the U.S. and Japan by Caves and Barton (1990) and Uekusa and Torii (1987), respectively. It is interesting to observe a certain degree of similarity as well as differentiation between the cross-section evidence on Korea's manufacturing industries and that on the U.S. and Japanese industries. As for the similarities, we can find positive and significant effects on technical efficiency of relative size of production and the extent of specialization in production, and negative and significant effect of the variations in capital-labor ratio within industries. The curvature influence of concentration ratio on technical efficiency is also confirmed in the Korean case. There are differences, too. We cannot find any significant effects of capital vintage, R&D and foreign competition on technical efficiency, all of which were shown to be robust determinants of technical efficiency in the U.S. case. We note, however, that the variables measuring capital vintage effect, R&D and the degree of foreign competition in Korean markets are suspected to suffer from serious measurement errors incurred in data collection and/or conversion of industrial classification system into the KSIC (Korea Standard Industrial Classification) system. Thus, we are reluctant to accept the findings on the effects of these variables as definitive conclusions on Korea's industrial organization. Another finding that interests us is that the cross-industry evidence becomes consistently strong when we use the efficiency estimates based on gross output instead of value added, which provides us with an ex post empirical criterion to choose an output measure between the two in estimating the production frontier. We also conduct exploratory analyses on the stability of the estimates of technical efficiency in Korea's manufacturing industries. Though the method of testing stability employed in this paper is never a complete one, we cannot find strong evidence that our efficiency estimates are stable over time. The outcome is both surprising and disappointing. We can also show that the instability of technical efficiency over time is partly explained by the way we constructed our measures of technical efficiency. To the extent that our efficiency estimates depend on the shape of the empirical distribution of plants in the input-output space, any movements of the production frontier over time are not reflected in the estimates, and possibilities exist of associating a higher level of technical efficiency with a downward movement of the production frontier over time, and so on. Thus, we find that efficiency measures that take into account not only the distributional changes, but also the shifts of the production frontier over time, increase the extent of stability, and are more appropriate for use in a dynamic context. The remaining portion of the instability of technical efficiency over time is not explained satisfactorily in this paper, and future research should address this question.

아토피피부염의 중증도와 심박변이도의 상관성 연구

유승민,유승연,김민희,윤영희,최인화,Yu, Seung-Min,Yoo, Seung-Yeon,Kim, Min-Hee,Yun, Young-Hee,Choi, In-Hwa 대한한방안이비인후피부과학회 2011 한방안이비인후피부과학회지 Vol.24 No.3

Background : There are findings indicating that the autonomic nervous system (ANS) is affected negatively in atopic dermatitis (AD). Heart rate variability (HRV) is a tool to examine ANS. But, studies investigation the relationship between AD and HRV is rare. Objective : The aim of this study was to investigate the correlation between atopic dermatitis severity and HRV and to find out the role of ANS in AD. Methods : Retrospective chart review was performed. The Severity Scoring Atopic Dermatitis (SCORAD) index and HRV parameter was investigated and analyzed. Results : There were 55 patients (25males and 30 females) who met the criteria. Objective SCORAD had significant positive correlation with HRT and Subjective SCORAD had significant negative correlation with SDNN, TP and VLF. Intensity item of SCORAD index had negative correlation with most HRV parameters, but TP, LF and LF/HF ratio had significant positive correlation with dryness. Conclusion : This study supports the concept that atopic dermatitis is a stress-responsive disorder and involves autonomic nervous system dysfunction.

한국(韓國) 제조업(製造業)의 기술적(技術的) 효율성(效率性) : 산업별(産業別) 기술적(技術的) 효율성(效率性)의 추정(推定)

유승민,이인찬,Yoo, Seong-min,Lee, In-chan 한국개발연구원 1990 韓國 開發 硏究 Vol.12 No.2

본(本) 논문(論文)은 기존의 경험적(經驗的) 산업조직론(産業組織論)에서 소홀히 취급한 기술적(技術的) 효율성(效率性)의 문제를 분석하기 위하여 광공업(鑛工業)센서스의 세세분류제조업별(細細分類制造業別) 사업체(事業體)를 대상으로 한국(韓國) 제조업(製造業)의 기술적(技術的) 효율성(效率性)에 관한 가장 미시적(微視的) 차원(次元)의 경험적(經驗的) 연구결과(硏究結果)를 제공한다. 기술적(技術的) 효율성(效率性)의 산업간(産業間), 국가간(國家間) 격차(隔差)를 성명하기 위해서는 우선 적절한 격차효율성지표(隔差效率性指標)의 선택이 매우 중요할 것이다. 이를 위하여 본(本) 연구(硏究)에서는 확률적(確率的) 생산경계(生産境界)를 수정최소자승법(修正最小自乘法)으로 추정한 후 각 산업별(産業別)로 기술적(技術的) 효율성(效率性)의 네가지 상이한 척도(尺度)에 대한 추정을 시도한다. 추정(推定) 결과 효율성(效率性) 척도간(尺度間)의 상관관계(相關關係)는 부가가치액(附加價値額)보다 생산액(生産額)을 종속변수로 한 경우가 다소 높은 것으로 나타났으나 전자(前者)의 경우가 보다 많은 산업(産業)에 대하여 효율성(效率性)의 추정(推定)을 가능하게 하기 때문에 산업간(産業間) 비교(比較)를 위하여 더 적절하다고 판단된다. 상당수의 산업(産業)에 있어서는 만족할 만한 효율성(效率性) 추정치(推定値)를 구하는 것이 불가능했지만 후속연구(後續硏究)의 관점에서 볼 때 기술적(技術的) 효율성(效率性)의 추정(推定)이 가능한 산업(産業)이 다수를 차지한 사실은 고무적 이라고 판단된다. 또한 종업원규모(從業員規模)가 영세한 사업체(事業體)들이 상대적으로 비효율적(非效率的)임을 알 수 있었다. Research on technical efficiency, an important dimension of market performance, had received little attention until recently by most industrial organization empiricists, the reason being that traditional microeconomic theory simply assumed away any form of inefficiency in production. Recently, however, an increasing number of research efforts have been conducted to answer questions such as: To what extent do technical ineffciencies exist in the production activities of firms and plants? What are the factors accounting for the level of inefficiency found and those explaining the interindustry difference in technical inefficiency? Are there any significant international differences in the levels of technical efficiency and, if so, how can we reconcile these results with the observed pattern of international trade, etc? As the first in a series of studies on the technical efficiency of Korea's manufacturing industries, this paper attempts to answer some of these questions. Since the estimation of technical efficiency requires the use of plant-level data for each of the five-digit KSIC industries available from the Census of Manufactures, one may consture the findings of this paper as empirical evidence of technical efficiency in Korea's manufacturing industries at the most disaggregated level. We start by clarifying the relationship among the various concepts of efficiency-allocative effciency, factor-price efficiency, technical efficiency, Leibenstein's X-efficiency, and scale efficiency. It then becomes clear that unless certain ceteris paribus assumptions are satisfied, our estimates of technical inefficiency are in fact related to factor price inefficiency as well. The empirical model employed is, what is called, a stochastic frontier production function which divides the stochastic term into two different components-one with a symmetric distribution for pure white noise and the other for technical inefficiency with an asymmetric distribution. A translog production function is assumed for the functional relationship between inputs and output, and was estimated by the corrected ordinary least squares method. The second and third sample moments of the regression residuals are then used to yield estimates of four different types of measures for technical (in) efficiency. The entire range of manufacturing industries can be divided into two groups, depending on whether or not the distribution of estimated regression residuals allows a successful estimation of technical efficiency. The regression equation employing value added as the dependent variable gives a greater number of "successful" industries than the one using gross output. The correlation among estimates of the different measures of efficiency appears to be high, while the estimates of efficiency based on different regression equations seem almost uncorrelated. Thus, in the subsequent analysis of the determinants of interindustry variations in technical efficiency, the choice of the regression equation in the previous stage will affect the outcome significantly.

우리나라 기업집단(企業集團)의 소유(所有)·경영구조(經營構造)와 정책대응(政策對應)

유승민,Yoo, Seong-min 한국개발연구원 1992 韓國 開發 硏究 Vol.14 No.1

"오너" 지배체제(支配體制)를 특징으로 하는 우리나라 대규모기업집단의 소유(所有) 경영구조(經營構造)는 개인자본주의(個人資本主義)를 마감하고 대중자본주의(大衆資本主義)를 발전시키는 데 제약요인(制約要因)이 되고 있다. 본고(本稿)에서는 소유(所有) 경영구조(經營構造)의 문제(問題)를 경제력집중문제(經濟力集中問題)의 일부로 파악하면서 선진자본주의경제(先進資本主義經濟)의 소유(所有) 경영구조(經營構造)를 참고기준으로 우리나라의 경제력집중문제(經濟力集中問題)를 생산집중(生産集中), 업종다변화(業種多邊化), 소유집중(所有集中), "그룹"식(式) 경영방식(經營方式), 금융기관(金融機關)의 역할(役割) 등을 중심으로 분석했으며, 이를 토대로 그동안 정부(政府)가 추진해 온 제반시책(諸般施策)을 평가하였다. 현황(現況)과 정책(政策)에 관한 병렬식(竝列式) 논의(論議)를 통하여 과거 출자규제(出資規制)와 여신관리(與信管理)를 중심으로 한 정부(政府)의 경제력집중대책(經濟力集中對策)이 경제력집중(經濟力集中)의 세가지 측면인 생산집중, 업종다변화, 소유집중 가운데에서도 주로 생산집중(生産集中)과 업종다변화(業種多邊化)를 규제했음을 보였다. 향후에는 소유분산(所有分散)을 중심으로 경제력집중대책(經濟力集中對策)을 재편(再編)할 필요성과, 생산집중(生産集中)과 업종다변화(業種多邊化)에 관한 규제는 가급적 축소하되 오히려 금융(金融) 산업(産業) 언론(言論) 등 주요부문간 다변화(多邊化)에 관한 규제도입(規制導入)의 필요성을 제기하였다. 또한 경영구조(經營構造)에 관한 정부개입(政府介入)의 타당성이 의문시되기 때문에 소유(所有)와 경영(經營)의 분리(分離) 및 독립전문경영체제(獨立專門經營體制) 등에 있어서 정부(政府)가 기업집단(企業集團)을 일정한 방향으로 유도하는 것은 자제되어야 함을 지적하였다. "Corporate control by owners" characterizes the current structure of ownership, control and management of big business groups in Korea. It has become an ever more serious obstacle for the Korean economy to end its distinctive "personal capitalism" and to transform the current system into people's capitalism. The current issue, the deconcentration of ownership, through the course of heated debates should be treated from an integrated perspective. That is, the debate should center on the concentration of economic power and it effects on national economy, instead of sticking to the issue of ownership-control issue per se. This paper, by referring to the historical experiences and development paths which advanced countries have already traveled, analyzes the respective aspects of the concentration issue in a rather descriptive and taxonomist manner - market concentration, business diversification, ownership concentration, integrated management of conglomerates, i.e., managing in groups' unit, and the roles of financial institutions. The government policies against the concentration of economic power have so far focused on the size of big business groups and their diversification activities. The two major policy measures are restrictions on cross-ownership and excess capital investment by big business groups, and controls on their credit deals. This paper strongly suggests that the government should change its current priorities in targeting its policies against concentration. The government should reduce the regulations on size and diversification, and focus its policies on substantial dispersion of corporate ownership. The efficacy of government intervention in the management and control of business enterprises seems quite dubious and even anachronistic given the extent of maturity of Korean firms. Therefore, it should be noted that the current regulation-oriented stance taken by the government against the management style of big business groups should be suppressed, as it has assumed some a priori and typical pattern in advance in directing big business groups, such as independent and specialized management in respective firms' unit. This paper, also, raises the need for introducing new regulations on inter-sectoral diversifications between finance, industry and the press.

Identification ofP. aeruginosa and A. baumannii causing nosocomial infection by using microarray-based assay

Seung Min Yoo(유승민),Kyung Hee Chang(장경희),Nae Choon Yoo(유내춘),Ki Chang Keum(금기창),Won Min Yoo(유원민),June Myung Kim(김준명),Sang Yup Lee(이상엽) 한국생물공학회 2005 한국생물공학회 학술대회 Vol.2005 No.10

Development of a Diagnostic Microbial Microarray for Infectious Disease

Seung Min Yoo(유승민),Kyung Hee Chang(장경희),So Young Yoo(유소영),Nae Choon Yoo(유내춘),Ki Chang Keum(금기창),Won Min Yoo(유원민),June Myung Kim(김준명),Sang Yup Lee(이상엽) 한국생물공학회 2004 한국생물공학회 학술대회 Vol.2004 No.4

폐결핵의 치료 중에 발생한 일시적인 방사선학적 악화를 보인 1예: 초기 CT 소견 (이달의 X-선)

유승민 ( Seung Min Yoo ),이화연 ( Hwa Yeon Lee ) 대한결핵 및 호흡기학회 2008 Tuberculosis and Respiratory Diseases Vol.65 No.4

DisplayPort 인터페이스 송신기 설계 및 FPGA 검증

유승민(Seung-Min Yoo),김민준(Min-Jun Kim),강진구(Jin-Ku Kang) 대한전자공학회 2015 대한전자공학회 학술대회 Vol.2015 No.11

멀티빔 도플러 센서 움직임 감지기의 구현

유승민(Seung-Min Yoo),채상훈(Sang-Hoon Chai) 한국정보기술학회 2021 한국정보기술학회논문지 Vol.19 No.3

A Doppler radar type sensor that uses a 10.525GHz microwave signal for motion detection is difficult to detect objects in a wide angular range because the angle of the transmitted beam is narrow when a single antenna is used. In order to solve this problem, the transceiver antenna, which is a component of the Doppler radar, is configured in the form of a multi-beam by combining several antennas having different phases, thereby realizing the object motion detection capability of a wide angle. The Doppler radar sensor fabricated by this study is composed of a multi-beam by combining four transmission/reception antennas with different phases to construct an array-type wide-angle motion sensor module with a detection function of 90° or more. In addition, by arranging three modules at 50° intervals, a wide-angle motion sensor with a detection angle of 180° or more could be implemented.

구조물 물성치 간접 추정의 정확도 향상을 위한 EQI 기반 관측 위치 순차적 최적화 기법

유승민(Yoo, Seungmin),송준호(Song, Junho) 대한토목학회 2018 대한토목학회 학술대회 Vol.2018 No.10