한ㆍ일 도시가스산업의 생산성 비교분석

최인수(In Su Choi),도범성(Bum Sung Do),박창수(Chang Soo Park),박중구(Jung Gu Park) 한국가스학회 2009 한국가스학회지 Vol.13 No.2

본고는 21세기 들어 고유가와 기후변화협약에 대응하여 중요성이 더해지고 있는 한국과 일본의 도시가스기업의 생산성을 분석하였다. 맘퀴스트 생산성 지수(Malmquist Productivity Index: MPI)를 통해 1997년부터 2005년까지 한국 30개, 일본 5개 기업들의 재무제표를 활용하여 기간 전체로, 그리고 수요의 구조변화를 나타내었던 2000년을 기준으로 이전과 이후의 생산성을 평가하였다. 분석의 결과, 첫째, 1996년~2005년 전체 기간의 MPI 누적지수에서 한국의 도시가스산업이 일본보다 상위에 있는 것으로 분석되었다. 그러나 기간별로 본 MPI 개선효과는 일본의 경우 1997~2000년 동안 -1.03%에서 2001~2005년 동안에는 -1.72%로 근소한 차이를 나타낸 반면, 한국의 경우에는 전반기 0.37%(금융외환위기를 경험한 98년 제외시 0.80%)이었지만 후반기에 -0.60%로 악화된 것으로 나타났다. 둘째, 후반기 한국의 MPI 악화는 기술적 효율성 지수보다는 기술변화 지수가 전반기 -0.88%(98년 제외시 0.29%)에서 후반기 -1.29%로 크게 악화된 것에 기인하는 것으로 분석되었다. 이에 따라 한국의 도시가스사업은 2001년 이후 악화되고 있는 생산성 증가율과 악화의 요인이 되고 있는 기술변화를 개선하는 정책적 노력이 필요하다. This article makes a comparative analysis on the productivity in gas distribution industry between Korea and Japan, using Malmquist productivity index(MPI). The estimated MPI during 1997~2005 shows that the productivity of Korean gas distribution industry has been generally higher than that of Japanese gas distribution industry. But Korean MPI made a drastic change from positive improvement (+ 0.37) during 1997~2000 to severe deterioration (-0.60) during 2001~2005, while Japan MPI has seldom changed. This change of Korean MPI is analyzed to result from the worsening of technical change rather than technical efficiency change. According to this result, Korean gas distribution industry needs to improve the technical change.

분리수거실시에 따른 재활용품 회수방안

박창수,Park, Chang-Su 환경보전협회 1991 환경정보 Vol.13 No.9

WBS 기반의 사업 및 시스템엔지니어링 관리 - 발사체 개발사업 적용사례 연구

박창수,권병찬,김근택,Park, Chang-Su,Kwon, Byung-Chan,Kim, Keun-Taek 한국시스템엔지니어링학회 2017 시스템엔지니어링학술지 Vol.13 No.1

Work breakdown structure is a central element in project management and systems engineering. Composing a quality work breakdown structure is essential for the success of any project. In this paper, extensive use of work breakdown structure during phase one of KSLV-II launch vehicle development program is presented. The advantages and disadvantages of applying WBS-centric program and systems engineering management to the project are reviewed.

창간특집 - 낙농육우인들의 아름다운 동행을 이끌다

박창수,Park, Chang-Su 한국낙농육우협회 2012 낙농·육우 Vol.32 No.6

한국형발사체개발사업 시스템엔지니어링 프로세스

박창수,김근택,Park, Chang-Su,Kim, Keun-Taek 한국시스템엔지니어링학회 2014 시스템엔지니어링학술지 Vol.10 No.2

The Korea space launch vehicle-II (KSLV-II) program aims at developing a national launch vehicle system capable of launching 1.5 ton satellite into a sunsynchronous orbit. It is the succeeding program to the Naro launch vehicle program. The KSLV-II is a large-scale complex system which requires a systematic approach to all parts of the program. The KSLV-II program is currently developing a tailored systems engineering process for its need. It references practices and lessons learned from developing Naro launch vehicle. Standardized NASA processes and INCOSE processes were also referenced and compared during development of the process framework. This paper introduces the systems engineering processes developed for the KSLV-II program.

반복 복호 횟수 감소를 통한 저전력 LDPC 복호기 설계

이준호,박창수,황선영,Lee, Jun-Ho,Park, Chang-Soo,Hwang, Sun-Young 한국통신학회 2007 韓國通信學會論文誌 Vol.32 No.9c

LDPC 부호는 4G 이동통신 시스템에 적합한 오류 정정 부호이다. 그러나 알고리듬의 특성상 좋은 BER 성능을 위해서는 반복 복호에 의한 많은 연산량이 요구된다. 본 논문에서는 복호지연과 전력 소모에 대한 복호기의 성능을 증가시키기 위하여 반복 복호 횟수를 줄이는 알고리듬에 대하여 제안한다. 제안된 알고리듬은 현재 LLR 복호값과 이전 LLR 복호값 사이의 변화를 측정하고 변화 방향을 예측하며, 패리티 검사식을 만족시켜 수렴속도를 높이도록 LLR 값의 sign 비트를 반전시킨다. 실험결과, 제안한 방법은 BER 성능의 감소 없이 반복 복호 횟수를 약 33% 정도 줄이는 것이 가능하며 감소된 반복 복호 횟수에 비례하여 소모 전력도 감소시킬 수 있다. LDPC Low Density Parity Check) code, which is an error correcting code determined to be applied to the 4th generation mobile communication systems, requires a heavy computational complexity due to iterative decodings to achieve a high BER performance. This paper proposes an algorithm to reduce the number of decoding iterations to increase performance of the decoder in decoding latency and power consumption. Measuring changes between the current decoded LLR values and previous ones, the proposed algorithm predicts directions of the value changes. Based on the prediction, the algorithm inverts the sign bits of the LLR values to speed up convergence, which means parity check equation is satisfied. Simulation results show that the number of iterations has been reduced by about 33% without BER performance degradation in the proposed decoder, and the power consumption has also been decreased in proportional to the amount of the reduced decoding iterations.

중국의 WTO 가입 전ㆍ후의 지역별 총요소생산성 변화와 결정요인 실증 분석

박창수 ( Chang Suh Park ),황춘산 ( Chun Shan Huang ) 한중사회과학학회 2012 한중사회과학연구 Vol.10 No.2

This paper analyzes the changes of total factor productivity(TFP) of 29 Chinese provinces during the period of 1995-2008. For doing this, the Malmquist productivity change index decomposed into efficiency change index and technical progress change index is used in comparing productivity performances prior to and after China`s 2001 entry into the World Trade Organization(WTO). Furthermore, 29 Chinese provinces are separated into three regions, eastern, middle, and western ones, to analyze productivity performances among these regions. In addition, GDP as output variable and fixed capital stock and number of employed workers as input variables are used in estimating the Malmquist productivity change index. The empirical results of this paper are as follows: First, although technical progress after China`s WTO entry was remarkably improved, efficiency after China`s WTO accession was continuously decreased. As a result, improvement of technical progress dominated deterioration of efficiency in China. Second, eastern region of China including Shanghai played very important role in increasing both China`s TFP and technical progress. Third, efficiency of eastern, middle, and western regions of China was all decreased so that improving efficiency will become one of the most important things for sustainable growth of Chinese economy. One of main reasons for deterioration of efficiency would be overinvestment in these three regions. Fourth, among the innovation provinces of China, the majority was coastal regions including Shanghai. Thus, it is necessary that tightening up the regional technical capability to reduce the gap between eastern and other regions of China. Finally, according to the empirical results of the determinants of TFP, market openness, FDI share, market transaction of technology and patent application play a positive role in improving TFP in China.

일반 논문 : 우리나라 중소 제조업의 생산성 성과와 그 결정요인: 정부의 정책자금 지원과 시장구조를 중심으로

박창수 ( Chang Suh Park ),이윤재 ( Yoon Jai Lee ) 한국중소기업학회 2011 中小企業硏究 Vol.33 No.2

본 논문은 우리나라 중소 제조업의 생산성 분석을 통해 경제적 성과를 살펴보고 시장구조와 중소 제조업 지원이 생산성에 미치는 효과를 실증 분석하였다. 우선 생산성 성과와 관련하여 중소 제조업, 중견 제조업, 그리고 대규모 제조업으로 나누어 살펴볼 때 중소 제조업의 생산성이 상대적으로 낮은 것으로 추정되었다. 중소 제조업의 생산성 증가를 산업별로 살펴보면 시계 및 시계부품 제조업, 코르크 및 조물 제품 제조업, 무기 및 총포탄 제조업, 화학섬유 제조업, 편조원단 및 편조제품 제조업 등에서 생산성 증가가 두드러졌으며, 우리나라 주력 산업이라 할 수 있는 반도체·전자산업, 그리고 자동차 산업의 생산성은 중하위권에 머무른 것으로 나타났다. 한편 총요소생산성의 결정요인으로 시장구조와 중진공의 지원액(대출액)을 고려하였는데 시장의 독과점 정도가 클수록 총요소생산성은 부정적인 반응을 보였으며 1인당 지원액은 (+)의 효과를 보이고 있으나 그 효과는 그리 크지 않은 것으로 나타났다. 이러한 흐름은 1인당 부가가치에도 유사한 영향을 보여 주었다. 다만 1인당 유형고정자산이 1인당 부가가치에 큰 영향을 미치는 것은 나타났다. 본 연구의 결과는 중소 제조업에 대한 금융 지원이 생산성 향상에 좀 더 긍정적인 효과를 미치도록 하기 위한 정책 개선이 필요함을 시사하고 있다. Credit loans for small-and-medium enterprises (SMEs) have been one of the major issues on justification for supporting small-and-medium sized firms by governments because the capital flow into small-and-medium sized firms is not easy due to asymmetric information and market failure. It has been well known that the supporting policies of the Korean government for small-and-medium sized firms are various and broad compared with those in advanced countries. However, there has not been enough research on objective evaluations of policy supporting for small-and-medium sized firms and there have been different opinions on the evaluation methods and data used in analyses. There has been some literature on the relationship between policy loan supporting and performances of SMEs in Korea. Kim (2004) used data on policy loan at firm-level over the period of 1998~2003 and analyzed the ratio of operating gains to revenue between firms with policy loan and firms without policy loan. Kim (2004) found that there is no difference between the two groups in the performance of the ratio of operating gains to revenue. However, there is some positive effect, in the short term, of policy loan on management improvement for the business establishment firms. Noh (2010), using firm-level data, empirically analyzed the outcomes of SMEs investment associated with policy loans from ``Small and medium Business Corporation``, a representative non-profit, government-funded organization. The sample size in Noh (2010) was about 20,000 SMEs supporting policy loans over the period of 2002~2008. He was concerned whether the policy loans made firms more profitable or do recipients simply have easier access to commercial credit without policy loans. According to the empirical results in Noh (2010), the policy loans, other things being equal, improved profitability of SMEs for the short-term period after the program was applied. The positive profit-enhancing effect is also stronger for start-up SMEs and SMEs in the earlier stages rather than older SMEs. Secondly, policy loans that have a significantly positive effect on the growth rates of sales is greater for the loans associated with venture SMEs in their start-up and early growth stages and with the commercialization of intellectual property rights and R&D results. Third, the effect of financial accessibility of the recipients to the commercial credit without policy loans has not been found in our financial data. These findings imply that when providing policy loans it is more desirable to target the prospective young SMEs rather than matured ones. This paper analyzes the trends of productivity performances of the manufacturing sector in Korea by separating the manufacturing sector into three groups over the period of 2000~2008 and empirically examines the determinants of productivity by focusing on government`s policy loans and market structure only for small and medium manufacturing sector over the period of 2005~2008 due to a data availability problem. In estimating total factor productivity, this paper uses the Malmquist productivity change index method, which decomposes productivity change index into efficiency change index and technical change index by using data envelopment analysis. In investigating productivity performances by industry size, this paper categorizes the sample of the Korean manufacturing sector used in this paper into three groups: small and medium sized manufacturing industries with less than 300 workers, middle-large sized ones with 300 or more workers and less than 1000 workers, and large-sized manufactures with 1000 or more workers. Based on three-digit manufacturing industry classification, the number of small and medium sized manufacturing industries, middle-large ones, and large sized ones is 82, 31, and 25, respectively, over the period of 2000-2008. The data used in estimating productivity performances is from the website of the Korean National Statistics Office. In estimating productivity, output is measured by value-added at industry-level and inputs are the number of workers as a proxy variable of labor and tangible fixed asset as a proxy of capital in production function. The data for policy loans is from the Small and medium Business Corporation. According to the results on total factor productivity using the Malmquist productivity change index, large-sized manufacturing industries achieved the highest productivity performance and small and medium sized manufacturing industries achieved the lowest productivity performance over the whole period. In finding the sources of productivity performance, technical progress has played a more important role in small and medium sized manufacturing industries, while efficiency improvement has played an important role in middle-large and large sized manufacturing industries. When we focus on the productivity performances by industry for small and medium sized manufacturing industries, manufacture of watches, clocks and its parts (C274), manufacture of articles of cork, straw and plaiting materials (C163), manufacture of weapons and ammunition (C252), manufacture of man-made fibers (C205), and manufacture of knitted fabric mills and fabric products (C133) are ranked the top 5 in productivity performance. On the other hand, major industries in Korea such as semiconductors, electronics and communication apparatuses, and motor vehicles are ranked in the middle class. This paper also empirically analyzed the determinants of productivity performances in the small and medium sized Korean manufacturing sector by focusing on government policy loans to support small and medium sized firms and market structure. The sample used in this paper is eighty industries for small and medium sized manufacturing sectors over the period of 2005~2008. In estimating the determinants of productivity performances, this paper uses panel data methods, that is, fixed effect model and random effect model, and one of them has been selected by the Hausman test. In measuring market structure, this paper calculates CR3 (concentration ratio of top 3 firms` sales share in the market) by industry based on 3-digit industry classification. According to the empirical results, there is a negative relationship between the degree of market power and productivity and the effect of government policy loans on productivity is very inelastic even though it has a positive relation with productivity performance. Furthermore, both government policy loans and tangible fixed assets also have a positive effect on value added per worker. However, the latter has more important role in improving productivity rather than the former. The empirical findings in this paper imply that a more effective government loan policy is required to improve the productivity performance of small and medium manufacturing firms in Korea. The limits of this paper are as follows: First, this paper uses the data at industry level rather than at firm level. However, firm level data would be more affordable because government loans are for individual firms and individual firm`s management behavior would be reflected in productivity performances. Therefore, research on firm level data might be more reasonable. Second, the time period for the empirical test is relatively short, but there are short-term and long-term effects of policy loans on productivity. However, due to data availability this paper deals with only short period data.

비모수적 방법을 이용한 한ㆍ일 정유회사의 생산성 분석

박창수(Chang-Suh Park) 에너지경제연구원 2004 에너지경제연구 Vol.3 No.2

The purpose of the study is to analyze the effects of market liberalization policy of Korea and Japan on productivity performance in petroleum refining sector. According to the results of productivity estimation using non-parametric Malmquist productivity indexes, Korean petroleum refining sector has improved productivity after market liberalization, but its level was lower than that of Japanese petroleum sector. In addition, according to the identification of innovative firms which shifted production possibilities frontier, Korean petroleum firms played a signification role in shifting production frontier before market liberalization, but it was vice versa after market liberalization. These results may result from differences in policies and mechanism between the two countries. However, there has been no market movements n Korea such as mergers and acquisitions and business cooperation between petroleum firms which was observed very actively in Japanese petroleum refining sector. More investment in R&D sector and vertical integration connecting up and down streams or creating new energy business areas as a specialized energy firm are suggested to improve competitiveness of Korean firms.

미국항공우주국 SLS 발사체 개발 동향

박창수(Park, Chang-Su) 한국항공우주연구원 2020 항공우주산업기술동향 Vol.18 No.1

우주왕복선 퇴역 이후 미국에서는 9년 동안 우주로 사람을 보내지 못했다. 올해 처음으로 미국의 상업 발사체로 사람을 국제우주정거장에 보냈다. 왜 이런 유인 우주 수송 능력에 공백이 발생한 것인가? 여기서는 우주왕복선이 퇴역하게 된 원인과 Constellation 프로그램의 취소 등에 대해 정리한다. 그리고 현재 개발 중인 Space Launch System의 현황과 향후 미국 유인 우주 프로그램의 방향에 대해 살펴본다. After the retirement of the Space Shuttle, the United States could not send a person to space from its soil for 9 years. This year using a commercial launch vehicle they have sent a crew to the International Space Station for the first time. Why was there a break in human space transportation capabilities? The retirement of the Space Shuttle and the cancellation of the Constellation Program is summarized here. The development status of the succeeding Space Launch System is described in detail. Also a brief outlook is given on the future of NASA’s human space program.