In order to establish preventive maintenance and to make a reasonable estimate of the required repair cost for bridges, the related history information of the existing bridge inspection and diagnosis was analyzed. It was analyzed that about 75% of the repair costs were required for the pavement, expansion joining, curb, and railings in the service area of bridges.

Recently, interest in the safety and maintenance of the structures is growing. However, due to the low-cost order placed by the ordering organization, the safety diagnosis specialized institution becomes insolvent and many problems have arisen due to insufficient inspection and diagnosis. Therefore, in this study, the current status of bid cost was examined through the survey of the practitioners and case analysis. As a result, Precision safety diagnosis, the criteria cost for structures with a floor area of less than 10,000 ㎡ is lowered to 80 % from the current standard. For structures larger than that, the current criteria cost are applied, but it is deemed necessary to strengthen the rigidity of the criteria cost.

염해에 따라 발생하는 보수시기와 보수로 유지되는 내구수명은 보수비용 평가에 매우 중요한 요소이다. 일반적으로 사용하는 결정 론적 보수비용 평가는 사용기간의 연장에 따라 계단식으로 증가하게 되며, 보수로 인해 변동되는 내구수명의 변화를 고려하지 못한다. 본 연구 에서는 확률론적인 보수시기 및 비용을 평가하기 위해, 염해에 노출된 콘크리트 교각을 선정하였다. 두 가지 배합과 염화물에 노출된 외부 환 경조건을 고려하여 염화물 거동을 평가하였으며, 도출된 내구수명과 수명에 대한 확률변수를 변화시키면서 보수시기 및 비용 변화를 분석하 였다. 변동계수의 변화에 따른 보수회수는 큰 차이가 발생하지 않았으나, 초기의 내구수명 연장이 구조물의 보수시기 및 비용에 큰 영향을 미 치고 있었다. 또한 확률론적 보수비용 산정 모델은 결정론적 모델과 다르게 연속적인 보수비용이 평가되므로 목표내구수명에 따라 보수회수 를 감소시킬 수 있는 효과적인 기법임을 규명되었다.

양파의 관행 수확과 저장 방식을 개선하여 벌크 상태로 수확하여 수송, 하역, 보관 및 저장할 수 있도록 톤백 및 와이어철제파렛트를 개발한 후 관행저장 방식과 벌크저장 후 저장성을 비교하고 그에 따른 노동투입시간 및 소요비용을 비교하여 양파의 산지물류비 절감 효과를 비교 분석하고자 하였다. 본 연구를 통해 개발된 톤백이 관행 톤백보다 길이방향 인장강도가 16% 높았으며, 개발한 와이어철제파렛트가 관행철제파렛트보다 약 10% 더 저장가능하고 차량 적재 효율도 2배 이상 향상되었다. 개발된 500 kg용 와이어 철제파렛트의 벌크저장과 관행 그물망 저장의 감모율에는 차이가 없었으나, 1,000 kg 이상 많은 양을 저장할 경우 와이어철제파렛트 벌크저장은 관행저장보다 감모율이 3.7% 높아 적합하지 않는 것으로 나타났다. 톤백을 이용한 벌크 수확이 관행 망 수확보다 노동시간이 50.1% 그리고 총 투입비용은 46.1% 감소할 수 있는 것으로 나타났다. 와이어철제파렛트를 적용한 벌크저장이 관행저장보다 총 저장비용이 28.8% 감소하였으며, 2016년 양파생산량 (1,298,749톤)의 30%를 와이어철제파렛트 벌크저장으로 대체할 경우 연간 183억 원을 절감할 것으로 추정된다. 따라서 현재 산지업체들의 와이어철제파렛트를 조기 도입하여 정착시키면 전국적으로 노동력 및 비용 절감에 상당한 효과가 있을 것으로 판단된다.

2014년 기준 13,698톤/일의 음식물쓰레기 발생량 중 공동주택과 감량의무사업장이 차지하는 비율은 각각 38%, 30%이고 계절평균 음식물쓰레기 함수율은 각각 81.5%, 76.2%로 높아 수증기로 증발시키는 건조공정에서의 열원소요비용을 높이는 원인이 된다. 건조 에너지의 주요 공급열원으로는 전기, 가스 및 기름 등의 화석연료이며, 이 중 전기 열원 사용이 가장 간편하고 적용성이 우수하지만 가스 열원에 비해 온실가스 배출량은 단위열량당 2.3배로 상대적으로 높다. 그리고 기름(Light oil, Heavy oil) 열원의 경우 연소 후 연관에 Soot와 같은 입자상물질의 누적에 의한 열전달속도 감소로 열회수 효율을 저감시킨다. 가스(LNG) 열원의 경우 가스유입 배관, 가스보일러 및 연소실이 추가로 필요하지만 연소 시 매연이나 미세분진 발생량이 적고, 일산화탄소와 질소산화물 배출량이 적고, 오존을 생성하는 탄화수소 배출량이 적고, 천연가스 정제비용이 낮고, 누설 시 공기보다 가벼워 대기 중으로 쉽게 확산되어 안전성이 높은 장점과 천연가스액화기술 발전으로 운송과 보관이 용이할 뿐만 아니라 전 세계적으로 약 100년 이상 사용 가능할 정도로 매장량이 풍부하다. 반면 가스 열원을 건조공정에 사용할 경우 연소 후 폐열의 대기 배출로 열회수 효율을 감소시켜 가스소비량 증가에 의한 운영비용 상승의 단점이 있다. 이를 보완하기 위해서는 기존의 단순 시간종료에서 최종부산물의 목표함수율에 도달할 경우 건조공정 자동종료로 가스소비량을 최소화 할 수 있는 방안도 적절한 대안이 될 수 있다. 건조공정 종료시간 자동화를 위해서는 제어시스템을 개발해야 하며, 종료시점은 폐쇄회로(Closed-loop recirculation system) 건조공정에서 수증기 배출량이 가장 높은 열교환기의 유입과 배출 온도차(⊿T)와 건조기의 배출과 유입 온도차(⊿T)로 설정이 가능하다. 이 중 열교환기 유입, 배출온도 변화가 짧은 시간에 크게 변화함에 따라 종료시점 범위 설정이 용이하지 않음에 비해 건조기 배출, 유입온도 변화는 상대적으로 안정적인 변화폭인 것으로 나타났다. 따라서 본 연구에서는 최종부산물의 목표함수율에 근접할 수 있는 건조 공정을 모니터링하여 적절한 운전종료시점을 설정할 수 있는 방안을 제시하기 위해 건조기 배출, 유입 온도차(⊿T)를 적용하였다.

This study extends research into whether disclosure of corporate and financial information is associated with firms’ costs of equity capital. This study sets out to examine empirically the determinants of corporate disclosure in the annual reports of 37 largest and most liquid firms listed on Kazakhstan Stock Exchange (KASE) in Kazakhstan. It also reports the results of the association between company-specific characteristics and disclosure of the sample companies. Based on the analysis of existing empirical research, the disclosure index has been constructed and regression analysis of the influence of the disclosure index on the cost of equity capital has been conducted. The obtained results show that the received findings correlate with foreign empirical studies, and the disclosure index in this sample has a negative impact on the cost of equity capital. Using cost of equity capital estimates derived from capital asset pricing model, we find that firms with higher levels of financial transparency are associated with significantly lower costs of equity capital. Economic theory assumes that by increasing the level of corporate reporting, firms not only increase their stock market liquidity, but also decrease the investors’ estimation risk, arising from uncertainty about future returns and payout distributions. The results show that firms on the Kazakhstan market can reduce their cost of equity capital by increasing the level of their voluntary corporate disclosures.

본 연구에서는 건설폐기물의 발생단계, 즉 건축물의 신축이나 해체현장에 투입하여 활용할 수 있는 이동식 혼합건설폐기물 분리･선별 장치를 개발하였으며, 이를 활용하였을 때 예상되는 건설폐기물 처리비용의 변화를 분석하였다. 이동식 혼합건설폐기물 분리･선별 장치는 1일 8시간 작업기준으로 16 ton의 혼합건설폐기물을 처리할 수 있게 설계하였다. 주요 처리시스템으로는 트롬멜을 사용하였으며, 1차적으로 무기물질과 유기물질로 분리･선별한 후, 무기물질은 다시 재활용 용도의 효율성을 고려하여 입형별로 15 mm 이하, 15~30 mm, 30 mm 이상으로 구분하여 분리할 수 있게 하였다. 유기물질 또한 1차적으로 무기물질과 분리･선별된 후 최종적으로 폐목재와 기타 가연성물질로 분리할 수 있도록 제작되었다. 이와 같은 사양을 가진 이동식 혼합건설폐기물 분리선별 장치의 제작비는 제작사별로 일부 차이가 있겠지만 1대당 약 75,000천원으로 산정되었으며 연간유지관리비는 약 101,600천원으로 책정되었다. 해체현장을 대상으로한 혼합건설폐기물의 처리 비용변화를 살펴보면, 현행 톤당 35,526원 이었으나 본 장치를 활용할 경우에는 장치 제작비 및 운영에 소요되는 비용과 재활용 처리비용까지 포함하면 51,480원으로 기존 처리방식 대비 약 45%가 증가하게 된다. 따라서 자원의 실질 재활용율을 높이고자 하는 측면에서는 오히려 현행의 매립비용의 상승이 필요할 것으로 판단되며, 영국의 사례와 같이 매립비용을 고형연료화 등의 자원 재활용 비용보다 높게 책정하여 시장에서의 자원재활용율을 높이는 정책적인 지원이 필요할 것으로 판단된다.

The purpose of this study was to suggest the foundation of LDA-based model for infrastructure maintenance cost evaluation. The LDA-based model enables to evaluate not only overall maintenance cost, but also various combination of each cell of risk matrix.

To lower the operational cost of microbubble generation by electrolysis, optimization of parameters limiting the process must be carried out for the process to be fully adopted in environmental and industrial settings. In this study, four test electrodes were used namely aluminum, iron, stainless steel, and Dimensionally Sable Anode (DSA). We identified the effects and optimized each operational parameter including NaCl concentration, current density, pH, and electrode distance to reduce the operational cost of microbubble generation. The experimental results showed that was directly related to the rate and cost of microbubble generation. Adding NaCl and narrowing the distance between electrodes caused no substantial changes to the generation rate but greatly decreased the power requirement of the process, thus reducing operational cost. Moreover, comparison among the four electrodes operating under optimum conditions revealed that aluminum was the most efficient electrode in terms of generation rate and operational cost. This study therefore presents significant data on performing costefficient microbubble generation, which can be used in various environmental and industrial applications.

The purpose of this study was to suggest the foundation of LDA-based model for infrastructure maintenance cost evaluation. The LDA-based model enables to evaluate not only overall maintenance cost, but also various combination of each cell of risk matrix.

본 논문은 교량의 예방적 유지관리 효과를 생애주기비용 절감 측면에서 분석 하였다. 예방적 유지관리는 현재 실시되고 있는 대응 적 유지관리 전략과 대비 되는 유지관리 전략으로 교량의 열화지연을 통해 궁극적으로는 교량의 사용수명을 연장 시키며 생애주기비용을 절 감시키는 유지관리 전략이다. 이러한 예방적 유지관리 효과를 분석하기 위해 교량의 공용연수에 따른 건전도 점수 변화 모델과 FHWA 자료를 바탕으로 한 국내 고속도로 교량의 건전도 점수에 따른 보수·보강 비용 모델을 제시 하였다. 제시한 복수의 모델과 국내외 참고 문헌을 바탕으 로 제안된 예방적 유지관리 항목(청소와 도장)의 비용과 주기를 활용하여 사용수명 100년까지의 표준교량(1,730 m2/교량) 당 생애주기 비용과 향후 20년간의 고속도로 총 유지관리 비용을 산정 하였다. 분석 결과 100년간 예방적 유지관리 활동으로 인해 교량 당 5억원의 절감효과를 볼 수 있으며 현재 예방적 유지관리 활동을 실시할 경우 20년 후(2035년)에는 총 1,837억원, 즉 연간 약 92억원의 비용 절감효과를 볼 수 있는 것으 로 분석 되었다.

This study examines whether Korean rating agencies such as Korea Investors Service (KIS), National Information & Credit Evaluation (NICE), and Korea Ratings Corporation (KR), incorporate corporate governance into their corporate bond ratings in Korea. We find that the Korean rating agencies assign higher ratings to the bonds issued by Chaebol (Korean business group) affiliated firms. Our results also indicate that those rating agencies give higher ratings to the bonds with greater foreign investor share ownership. Moreover, if the rating agencies value corporate governance, higher rated firms should issue bonds at lower yield to maturity. We discover that Chaebol affiliation is counted favorably by the rating agencies. We find that investors are willing to pay lower risk premium for bonds with higher institutional ownership, but higher risk premium to bonds with greater equity ownership in the form of depository receipts. Therefore, even if the rating agencies and investors in Korea consider corporate governance (Chaebol affiliation and ownership structure) an important determinant in bond ratings and the yields to maturity, they have opposite views on institutional ownership and share ownership in the form of depository receipts

Due to the enlargement and high-rise of reinforced concrete structure, the application of high functional material is required. However, high-strength bar is recently introduced to the country and the material is insufficient to measure the variation of quantity of rebar quantitatively when using high-strength bar. For these reasons, this study is to provide useful data in cost decision making when applying high-strength bar at a stage of architectural project planning. For residence-commerce complex buildings, we set up six types of conditions such as in case of using only rebar, in case of using only high-strength bar, in case of using rebar mixed with high-strength bar and so on. With the standard of study model 1 that applies only SD400 regardless of rebar diameter, the analyzed result of rebar variation and the cost change of construction in other study model is as follows. When the rebar amount and cost in study model I was 100%, each ratio was 88.3% and 90.5% in study model II, 80.2% and 83.4% in study model III, 91.9% and 93.5% in study model IV, 88.9% and 87.7% in study model V and 82.4% and 85.5% in study model VI. Therefore, in case of rebar amount and construction cost, study model III was evaluated as the best that was applied only SD600.

The objective of this study is to investigate the potential use of MSW incineration fly ash as an economic material for the removal of heavy metals (Pb, Mn, Fe, and Cu) from AMD. Batch adsorption experiment was conducted to examine the effects of pH, adsorbent dosage and contact time on metal ions removal in synthetic AMD using MSW incineration fly ash. Precipitation of calcium hydroxide and sodium hydroxide was used for comparison with MSW incineration fly ash by adjusting the pH (5 ~ 11) by coagulation method with 20 min reaction time. Comparing the application of Ca(OH)2 and Na(OH), fly ash proves more efficient which may be due to its porosity and chemical composition. The results from adsorption studies showed that maximum adsorption rate was achieved at 0.4g dose when various fly ash dosages were added to the solution with 60 min optimum time and removal efficiency of heavy metals was over 96%. The effectiveness of fly ash can be related to its high calcium (CaO 55%) content. Efficiency of heavy metals removal was directly linked to the amount of fly ash in the reaction mixture and to the final pH attained. pH plays a significant role in heavy metal uptake. The main removal mechanism was adsorption at the surface of the fly ash together with the precipitation and co- precipitation from the solution with chemicals. Therefore the use of MSW incineration fly ash for treatment of AMD would represent a new market opportunity for this waste product. It can also be useful for neutralizing AMD and possibly reduce its adverse effects to the environment with efficient removal of metal ions from AMD.

The Goal of research is that budget of maintenance were estimated in network-level bridges. We determined the life cycle of exchangeable bridge element with HBMS(Highway Bridge Management System) data and In-depth Inspection Results by the survival analysis probability model. We developed the method that predicted cost of maintenance in all of the highway bridge in korea considering a characteristics of failures.

During the last two decades, fiber reinforced polymer (FRP) reinforcing bars for concrete structure has been extensively investigated and a number of FRP bars are commercially available. However, major shortcomings of the existing FRP bars are its high initial cost and low elastic modulus compared to conventional steel bars. Because of these reasons, KICT in Korea have developed the FRP Hybrid Bar which have the concept of material hybridization for concrete structures, especially for marine and waterfront concrete structures. In this study, for the discussing the applicability of FRP Hybrid Bar to real concrete structures, life cycle cost analysis were performed on small bridge and discussed considering various kinds of maintenance cases.

A telerobot offers a more engaging and enjoyable interaction with people at a distance by communicating via audio, video, expressive gestures, body pose and proxemics. To provide its potential benefits at a reasonable cost, this paper presents a telepresence robot system for video communication which can deliver speaker’s head motion through its display stanchion. Head gestures such as nodding and head-shaking can give crucial information during conversation. We also can assume a speaker’s eye-gaze, which is known as one of the key non-verbal signals for interaction, from his/her head pose. In order to develop an efficient head tracking method, a 3D cylinder-like head model is employed and the Harris corner detector is combined with the Lucas-Kanade optical flow that is known to be suitable for extracting 3D motion information of the model. Especially, a skin color-based face detection algorithm is proposed to achieve robust performance upon variant directions while maintaining reasonable computational cost. The performance of the proposed head tracking algorithm is verified through the experiments using BU's standard data sets. A design of robot platform is also described as well as the design of supporting systems such as video transmission and robot control interfaces.

This research is aimed the furthest development of the conception of Human capital formation. The study made on the base of methods of scientific classification and systematization; dialectical method and the method of scientific abstraction, systematic and comparative analysis; expert assessment and ratings. Formation of the competitive human capital is one of the most important goals of modern development of Kazakhstan in condition of the innovative economy construction. In this context the necessity of formation and development of the effective human capital considerably increases. Realization of this requires definition of a technique of measurement of its cost as well. The authors attempt to calculate the value of human capital for Kazakhstan during independency time. In order to determine the methods of its quantitative and qualitative assessment different methodological ways for human capital research are studied. On the basis of the study, it was revealed that formation of the competitive human capital can't be considered in a separation from development and modernization of system of quality education, improvement of the employment sphere, worthy payment for work.

We have tested the measuring system that can monitor the dynamic behaviour of floating structure by various sensors. In this paper, we present a initial result using a low-cost GPS sensor, which showed the inaccurate position and insufficient frequency for a floating structure.