철골세우기 작업의 영향요인별 현장생산성 측정 및 분석

허영기,이지용,윤석헌,태용호,안방률 한국건축시공학회 2009 한국건축시공학회지 Vol.9 No.2

In today's construction industry, buildings have been more complicated and higher, the demands of steel works have been increasingly concerned, which makes the schedule planning and management more significant. However, in actual construction sites, management is more based on a manager's construction experience than productivity data accumulated in previous projects. Moreover, most of the existing studies also featured a theoretical approach rather than an analysis of data straightforwardly collected in sites. In this study, a steel-erection site was visited to collect productivity data. The study found that there were significant disparities between aboveground work productivity and underground work; one tower crane operated work and two tower crane operated; and work productivity conducted in clear weather condition, cloud and rainy. However, the productivities of ‘first node on ground’ and ‘second node on ground’ were estimated similar. The productivity data collected and factors affecting the productivity will help managers to plan and control their similar steel-erection works. This study will also be beneficial for those performing related studies. In today's construction industry, buildings have been more complicated and higher, the demands of steel works have been increasingly concerned, which makes the schedule planning and management more significant. However, in actual construction sites, management is more based on a manager's construction experience than productivity data accumulated in previous projects. Moreover, most of the existing studies also featured a theoretical approach rather than an analysis of data straightforwardly collected in sites. In this study, a steel-erection site was visited to collect productivity data. The study found that there were significant disparities between aboveground work productivity and underground work; one tower crane operated work and two tower crane operated; and work productivity conducted in clear weather condition, cloud and rainy. However, the productivities of ‘first node on ground’ and ‘second node on ground’ were estimated similar. The productivity data collected and factors affecting the productivity will help managers to plan and control their similar steel-erection works. This study will also be beneficial for those performing related studies.

산업연관분석을 이용한 중국 철강산업의 경제적 파급효과 실증분석 -생산유발효과, 수입유발효과, 부가가치유발효과를 중심으로-

안병국 ( Byung Kuk Ahn ),최영훈 ( Young Hun Choi ) 한중사회과학학회 2014 한중사회과학연구 Vol.12 No.1

Iron&Steel is key industry in China, which plays an important role in terms of GDP, tax revenue, and employment. Furthermore, because of it`s characteristic of grouping, steel industry`s contribution, at the province level, is more significant. China`s steel industry had kept it`s quantitative expansion since the foundation of China in 1949, and became world`s largest crude steel producing country in 1996. In 2012, China`s crude steel production stands at 708 million metric tons, accounting for 47% of world`s crude steel production. According to China`s 12th Five-Year Plan of Iron&Steel, which is backbone for steel industry policy of China, restructuring, rationalization of steel mill`s distribution, procurement of raw materials, and enhancement of globalization will be emphasized for sustainable growth of steel industry. In order for proving steel industry`s importance in China, this study, through input-output model, conducted empirical analysis on Chinese steel industry`s economic effect such as production induced effect, import induced effect, added value induced effect, forward linkage effect, and backward linkage effect etc.. And on the basis of literature survey, this study looked into Chinese steel industry`s historical development path and it`s outlook. Research results shows that steel industry ranked first among China`s 42 industry in terms of production induced effect. And China`s steel industry, with the help of government`s policy support, is expected to see both quantitative expansion and also qualitative improvement, with China maintaining it`s hegemony in global steel industry.

韓国鉄鋼産業の対日競争力分析

한기조,이홍배 한일경상학회 2009 韓日經商論集 Vol.42 No.-

This paper examines Korean steel industry's intra-industry trade(IIT) by disentangling vertical from horizontal IIT, and analyzes the determinants of both IIT types in trade with Japan during the period of 1991-2006. Korean steel industry's IIT with Japan has decreased from 1991 to 2006. This is because the competitiveness of Korean steel industry has weakened relatively. However, vertical intra-industry trade(VIIT) has increased faster than horizontal intra-industry trade(HIIT). especially its high quality VIIT, which has increased faster than low quality VIIT, implying that Korean steel industry's product quality has improved over time. and Korea's high quality VIIT is lager in trade with Japan. And the regression results show that the scale of economies have a positive effect on IIT, and the reduction of trade barriers have a positive effect on HIIT and a negative effect on VIIT. Hence, three strategies for improving competitiveness in korea's steel industry and helping it catch up Japanese steel industry are as follows: The first strategy is solving the disproportion among the production processes and increasing efficiency in production through structural reform like as M&As between firms. The second is developing new technology in production process and more high value-added products. Finally the third is scaling up the size of steel-distribution industry and improving its service.

고대 김해의 철생산과 묘제(墓制)의 변화에 대하여

신보배(Shin Bo-Bae) 동북아시아문화학회 2011 동북아 문화연구 Vol.1 No.26

Tombs in Gimhae were changed from wooden chamber tombs to stone-lined tombs between the 3rd century and the 5th century. The reasons are explained from various parts such as political reasons, exterior factors, and interior problems. This writer thinks that the environmental factor is one of those reasons. In terms of materials of tombs, the material was changed from 'stone' to 'wood'. In particular, people who used stone-lined tombs were the middle class and under. The fact that the top class of people used wooden chamber tombs while the lower class used stone-lined tombs shows wooden chamber tombs were high quality tombs. Then, this researcher has a doubt why tomb materials should be changed and the woods might become insufficient suddenly. Therefore, this writer examined the reason and found out that wood was used in coffins and chambers, production of steel and earthenware, and daily life. Among the reasons, this study focused on lumber consumption caused by the production of steel. This study looked into the size of steel production in Gimhae and impossible effect on the wood shortage phenomenon. Accordingly, the study looked at the size and the location of steel remains and charcoal kiln areas in Gimhae as well as the places in which the steel was consumed. There were steel goods consumed in usual life and burial accessories and exported to surrounding countries. Among them, this study measured the number of steel goods as burial accessories. According to this researcher's estimation, the woods necessary to produce 1kg steel were four oak trees. Based on the measurement, 7,700 trees were consumed to make burial ironware in Gimhae Daesungdong tombs, Gimhae Yangdongli tombs, and Gimhae Yeanli tombs.

한국상품에 대한 통상분쟁 고찰 : 철강 반덤핑 제소를 중심으로

김창모 한국경영컨설팅학회 2018 경영컨설팅연구 Vol.18 No.3

2018년 5월 1일 미국 트럼프 대통령은 백악관에서 한국 정부와의 합의에 따라 한국산 철강제품에 대해 고율의 추가 관세를 부과하는 무역확 장법 232조 시행을 면제한다고 발표했다. 그러나 문제는 바로 다음날인 2018년 5월 2일 미국국제무역위원회(ITC)가 한국을 비롯한 5개국 철강선 재에 대해 최고 147%에 달하는 반덤핑 관세 부과를 발표 했다. 미국이 일괄 관세를 면제하는 대신 반덤핑 관세와 수입규제 조치로 보호무역을 한층 강화하고 나선 것이다. 그 동안 자유무역주의가 이례적 인 것이고 교역 역사를 통하여 통상분쟁은 언제나 있어왔던 일이지만 대외의존도가 78%에 달하는 한국의 입장에서는 어렵더라도 이에 효과적 으로 대처하는 것이 아주 중요한 일중의 하나가 되었다. 여러 가지 형태의 수입규제 중에서 무역구제제도 중의 하나인 반덤핑 조치는 WTO 협정국별 관련 법령에 근거를 둔 대표적인 조치이다. 한국 상품에 대한 규제를 보면, 반덤핑이 전체 수입 규제의 80%를 차지하고 있어서 한국 상품에 대한 통상 분쟁은 반덤핑 조치가 그 근본적인 원인이 되고 있음을 알 수 있다. 또한 2018년 3월 5일 기준으로 수입규제 총 196건 중에서 철강이 93건을 차지하여 규제대상 1위를 차지하고 있다. 철강에 대한 반덤핑 제소의 경우 미국, EU, 캐나다 등 선진국이 주로 제소를 하고 있는 것으로 나타났다. On May 1, 2018, the President of the United States, Donald Trump announced at the White House that he would exempt the implementation of the Trade Expansion Act, which imposes a high additional tariff on korean steel products under an agreement with the Korean government. The problem, however, is that the U.S. International Trade Commission (ITC) announced, on May 2, 2018, the very next day, that it would impose anti-dumping tariffs of up to 147 percent on steel rods from five countries, including Korea. The United States has been stepping up its trade protection with anti-dumping measures and import control measures, instead of waiving a package tariffs. Although free trade has been unusual and trade disputes have always occurred throughout on trade history. It has been very important for korea to cope with this issue, even if it is difficult for it to be dependent of foreign countries. Among the various types of import regulations, anti-dumping measures, one of the trade relief measures, are representative of those based on relevant laws by the WTO member countries. To sum up the regulations on Korean products by type, the anti-dumping disputes over Korean products may be the root of the import control measures. As anti-dumping cases account for 157 cases out of 196 for 80 percent of the total import regulations. In addition, anti-dumping cases were found to be the case in which the United States, the EU and Canada are mainly suing Korean steel products. It is time to pay more attention to anti-dumping lawsuits, which account for most of the trade dispute over Korean products. And analyzing and compiling the cases of anti-dumping will be one of the ways to cope with future anti-dumping disputes. This study focuses and analyzes the status of import control measures for Korean steel products, the rules and policies of the WTO of anti-dumping measures, the anti-dumping systems of the United States, EU, and Canada, and the case study.

Productivity Analysis of Steel Works for Cost Estimation of Public Projects in Korea

윤석헌,태용호,안방렬,안성훈,허영기,조훈희 대한토목학회 2012 KSCE JOURNAL OF CIVIL ENGINEERING Vol.16 No.1

The steel fabrication and installation works in a steel-structured building project account for 20% of the entire construction cost. In estimating construction costs, a few parameters are more significant than work item productivity. However, the Standardized Productivity (SP) of steel works presented in Poom-Sam, which is the standardized estimating guide system used in the public sector in Korea, has rarely been updated since its establishment in the 1970s. In order to update and improve its structure and figures, 15construction sites and 5 steel fabrication shops were visited over a period of two years. From the study, it was found that the structure of Poom-Sam was rather complex and outdated and that the average SP of the works analyzed from the research was approximately 85% of the current SP. Moreover, the effect of the productivity differences on total construction cost was approximately 10%. The productivity improvements and amended Work Breakdown Structure (WBS) are attributable to the technology advancements in equipment and construction methods over the past two decades. The results of this study will improve the reliability and accuracy of cost estimation in steel works.

원자력발전소 2차측 습증기계통 주요지점별 부식 발생현황 분석

이경희,이영우,한호석,신성용,성기방 한국부식방식학회 2019 Corrosion Science and Technology Vol.18 No.4

Pipes and components of the secondary system in the pressurized water reactor (PWR) are mainly comprisedof manufactured carbon steel. Thus, the generated carbon steel corrosion products are transported into thesteam generator and deposited, thereby deteriorating the integrity of the steam generator. Environmentalcondition in the secondary system of the PWRs differs across different locations. So, the corrosion rateand types of corrosion products depend on specific locations in the secondary system. In this study, thequantity and chemical compositions of corrosion products generated in various locations that vary in differenttemperatures and chemistry conditions were investigated. As a result of evaluating the PWR “Unit A” thatis in current operation, the amount of corrosion products generated in the section of high temperature feedwatersystem was identified as the largest source in the secondary system. Major components of corrosion productswere iron oxides such as magnetite, hematite, and lepidocrocite.

Analytical model of corrosion-induced cracking of concrete considering the stiffness of reinforcement

Bhargava, Kapilesh,Ghosh, A.K.,Mori, Yasuhiro,Ramanujam, S. Techno-Press 2003 Structural Engineering and Mechanics, An Int'l Jou Vol.16 No.6

The structural deterioration of concrete structures due to reinforcement corrosion is a major worldwide problem. Service life of the age-degraded concrete structures is governed by the protective action provided by the cover concrete against the susceptibility of the reinforcement to the corrosive environment. The corrosion of steel would result in the various corrosion products, which depending on the level of the oxidation may have much greater volume than the original iron that gets consumed by the process of corrosion. This volume expansion would be responsible for exerting the expansive radial pressure at the steel-concrete interface resulting in the development of hoop tensile stresses in the surrounding cover concrete. Once the maximum hoop tensile stress exceeds the tensile strength of the concrete, cracking of cover concrete would take place. The cracking begins at the steel-concrete interface and propagates outwards and eventually resulting in the through cracking of the cover concrete. The cover cracking would indicate the loss of the service life for the corrosion-affected structures. In the present paper, analytical models have been developed considering the residual strength of the cracked concrete and the stiffness provided by the combination of the reinforcement and expansive corrosion products. The problem is modeled as a boundary value problem and the governing equations are expressed in terms of the radial displacement. The analytical solutions are presented considering a simple 2-zone model for the cover concrete viz. cracked or uncracked. A sensitivity analysis has also been carried out to show the influence of the various parameters of the proposed models. The time to cover cracking is found to be function of initial material properties of the cover concrete and reinforcement plus corrosion products combine, type of rust products, rate of corrosion and the residual strength of the cover concrete. The calculated cracking times are correlated against the published experimental and analytical reference data.

염수분무 환경에서 알루미늄-크롬 용융도금강판의 부식생성물이 내식성에 미치는 영향

임병문,홍승현,정재인,최장현,정원섭 대한금속재료학회 2003 대한금속·재료학회지 Vol.41 No.10

The effect of corrosion products of hot-dip Al-Cr steel sheet on the corrosion resistance were investigated. The results of XRD and XPS measurements showed that there was not found a hydroxide type corrosion product on the surface of aluminized steel after salt spray test(SST) but there was found some cracks in the surface layer which accelerates corrosion during SST. In Al-Cr coated steel case, the main phase of the corrosion products after salt spray test was found to be Al(OH)₃. The polalization curves of aluminized steel after SST shows that there was no passivation layer. For the Al coated layer, a porosity in the Al-oxide film on the surface layer leads to preferential corrosion. After the Al coated layer was completely removed, the Al_(5)Fe₂layer was selectively corroded and then, the steel substrate was exposed to the electrolyte. However, the polalization curves of Al-Cr coated steel after SST shows that the passivation layer was formed, which could increase the corrosion resistance of Al-Cr coated steel. In case of the Al-Cr coated layer, the densely covered hydroxide layer of Al(OH)₃and the intermetallic compound layer of Al_(13)Cr₂became a barrier against further corrosion after the Al layer was removed. In this case, corrosion was not proceeded even through the same current density. The densely covered hydroxide of Al(OH)₃and the intermetallic compound layer of Al_(13)Cr₂were considered to be one of the reasons of high corrosion resistance for Al-Cr coating.

Ownership Type, Firms' Strategies, Business Duration, and Productivity: Evidence from Korea's Iron and Steel industry

배미경 한국경제통상학회 2014 경제연구 Vol.32 No.2

본 연구는 한국철강산업에서 생산과정상 계열사간 거래가 있는 계열사들 (AF) 과 그렇지 않은 독립기업들 (IF) 로 나누어 기업의 성과보상제도, 외국기업과의 전략적 제휴, 기술전략, 그리고 특허권 및 지적재산권활용 등의 기업전략이 생산성증대에 미치는 효과가 어느 정도의 차이를 보이는 지를 규명하기 위해 고정효과 확률적 생산경계모델을 2006-2011년 한국철강산업 내의 기업미시패널데이터에 적용해 이를 추정했다. 실증분석결과 계열사들은 독립기업들과 기술진보율은 비슷하나 기술적 효율성의 악화로 총 요소생산성증가가 독립기업들보다 훨씬 저조한 총 요소생산성의 하락까지 보이고 있다. 또한 총 전략의 수와 기술전략의 수는 철강산업 내 기업들의 생산성증가에 기여하고 있다. 한편 공동기술개발, 기술제휴, 공동브랜드로 구성된 기술전략이 생산성증대에 미치는 효과를 2006-2011년 표본기간 내내 생존한 기업들과 그렇지 못한 기업들로 나누어 추정했으며 또한 기업들의 소유구조의 변동에 따라 기업들을 네 그룹으로 나누어 각각 이를 추정했다. 표본기간 내내 생산에 참여하지 못한 기업들은 표본기간 내내 생산에 참여한 기업들보다 높은 기술진보율, 기업전략의 높은 생산성기여율은 보이고 있으나 효율성의 악화로 총 요소생산성 증가율은 거의 0%로 하락하고 있다. 소유구조의 변동에 따른 실증분석결과는 독립기업에서 계열사로 전환한 기업들과 독립기업과 계열사 간을 두 번 이상 이동한 기업들에서 가장 높은 15.2%의 기술진보율을 볼 수 있으며 독립기업만을 고수하고 있는 기업들은 계열사만을 고수하고 있는 기업들 보다 더 높은 기술진보와 효율성향상에 의한 생산성증대를 통해 경쟁력을 강화하고 있다. 그러므로, 기술진보와 생산성증대를 통한 국제경쟁력향상을 달성하기 위해서는 한국철강산업 내 기업들의 특화된 기술전략의 실행이 필요하다고 본다. This paper investigates the extent to which the strategies of firms affect productivity growth according to changes in ownership type and business duration by applying a fixed effect stochastic frontier production function (FE SFPF) model to a firm-level panel data set for the period 2006-2011, using Korea's iron and steel industry as the research context. Empirical results show that while affiliated firms (AF) and independent firms (IF) achieved similar technical progress (TP), AF's far worse changes in technical efficiency caused its total factor productivity (TFP) growth to fall far below the TFP growth of IFs. The number of strategies and the number of technology strategies specifically had positive effects on TFP growth across all firms in the Korean iron and steel industry. Firms that were not operational throughout the sample period showed higher TP and larger positive changes in firms' strategies but worse performances in technical efficiency, which caused its TFP growth to plummet to 0%. Firms changing from IF to AF, and those that alternated between AF and IF more than two times, achieved an astonishingly high TP of 15.2%. Regarding TP, and changes in technical efficiency, firms maintaining IF outperformed firms maintaining AF, which verifies that IF had higher productivity-enhancing competitiveness than AF. Therefore, specific strategies on technology need to be implemented to promote technical progress and, ultimately, productivity growth, to enhance the global competitiveness of firms in the Korean iron and steel industry.