지구 온난화 가속화에 따른 환경 규제 강화 속에서, 유럽연합(EU)은 2050년 기후 중립(Net-Zero) 달성을 목표로 ‘Fit for 55’ 패키지 를 발표하고 해운 부문을 탄소배출권 거래제(EU ETS)에 단계적으로 편입시키고 있다. 본 연구는 EU ETS의 해운 부문 적용이 우리나라 해 운선사에 미치는 경제적 영향을 정량적으로 분석하고, 온실가스 저감 수단으로서 바이오연료 사용의 경제성을 평가하여 효율적인 대응 방 안을 모색하는 것을 목적으로 한다. 이를 위해 2024년 EU MRV에 보고된 THETIS-MRV 공개 데이터를 활용하여 국내 해운선사가 소유·관리 하는 선박의 연료소모량과 탄소배출량을 분석하였다. 분석 결과, EU ETS가 전면 적용되는 2026년 이후 국내 해운선사가 부담해야 할 연간 탄소배출권 비용은 약 1,262억 원(약 7,700만 유로) 이상으로 추정되며, 선종별로는 컨테이너선과 자동차운반선의 부담이 가장 큰 것으로 나 타났다. EU ETS 대응 방안으로 유럽 관련 항차에 바이오연료를 적용한 결과, EU/EEA 회원국 간 항차 및 EU 항만 내 구간에서 바이오연료 를 사용하는 경우가 가장 높은 비용효과성을 보였다. 그러나 현 시점에서는 바이오연료의 높은 가격으로 인해 EU ETS 비용 절감만을 목적 으로 한 사용은 경제적 타당성이 확보되지 않았다. 비용–편익 분석 결과, 2025년 말 EUA 가격(€82.22) 기준으로 바이오연료와 기존 화석 연료 간 가격 차이가 USD 75 이하로 축소될 경우 경제적 타당성이 확보되는 것으로 분석되었다. 이러한 결과는 바이오연료 확산을 위해 탄소가격 신호에만 의존하기보다는, 연료 가격 격차 완화를 위한 정책적 지원과 공급 인프라 구축이 병행될 필요가 있음을 시사한다.

현재 해운업계는 환경 규제 강화와 인력 부족이라는 구조적 도전에 직면하고 있으며, 자율운항선박은 이에 대응할 수 있는 기 술적·친환경적 대안으로 주목받고 있다. 본 연구는 LNG 연료를 사용하는 자율운항 LNG운반선, 컨테이너선, 벌크선을 대상으로 초기투자 비용(CAPEX)과 유지관리비용(OPEX)을 분석하고, 시나리오 기반의 경제성 분석을 통해 자율운항 시스템 도입 효과를 정량적으로 검토하 였다. 분석 결과, 자율운항 기술과 LNG 연료의 결합은 경제성과 환경 지속 가능성을 동시에 확보할 수 있으며, 특히 컨테이너선이 가장 높은 경제성을 보이는 것으로 나타났다. 향후 연구에서는 자율운항선박의 실증 데이터 축적과 차세대 친환경 연료를 적용한 경제성 분석 이 필요하다. 본 연구는 해운업계에서 장기 투자전략 수립을 위한 기초자료를 제공하는 데 목적이 있다.

This study aims to present a methodology and the corresponding results of an economic analysis, incorporating both costs and benefits, to assess the feasibility of introducing a smart on-board truck scale.The cost estimation was conducted based on direct expenditures associated with the installation and operation of smart on-board truck scales. The benefit analysis was performed by evaluating the reduction in social costs resulting from the mitigation of overloading, including transportation infrastructure maintenance costs, traffic accident costs, and environmental costs. The economic analysis outlines the variables required for each phase of the smart on-board truck scale implementation, along with their reasonable value ranges. In consideration of the uncertainty regarding the effectiveness of the smart on-board truck scales, a quantitative assessment of the impact of individual variables on the economic indicators was carried out through scenario analysis, focusing on key variables. The influence of the vehicle service life, the service life of the smart on-board truck scale, and personnel expenses—each related to installation and operation—on the benefit-cost ratio (B/C) and net present value (NPV) was determined to be limited. In contrast, the overload crackdown rate exhibited the most significant impact on the B/C and NPV, as it directly increased the number of vehicles contributing to measurable benefits. Notably, an increase in the discount rate led to a decrease in the values of both economic indicators. This outcome is expected, as the discount rate reduces the present value of future costs and benefits by increasing the denominator in the calculation. The introduction of smart on-board truck scales enables the achievement of economic feasibility in preemptive overload enforcement. Therefore, progressively expanding the number of vehicles equipped with smart on-board truck scales is essential to maximize their effectiveness in the near term.

The optimization of pellet fuels composed of rice straw, mustard straw, and sawdust was investigated in the present study to improve their properties and utility. Response surface methodology (RSM) and an artificial neural network (ANN) integrated with a multi-objective genetic algorithm (MOGA) were applied to optimize pellet composition for enhanced heating value and minimized ash, nitrogen, and sulfur content. An optimal blend of 74.40% rice straw, 15.60% mustard straw, and 10% sawdust was identified by RSM. These proportions were closely approximated by the MOGA-ANN model within ±1%, and the results were confirmed through experimental validation. Combustion ion chromatography was also used, to analyze the biomasses and the optimized blend, revealing reduced chloride (4189 mg/kg) and sulfur (2716 mg/kg) levels. These results were validated subsequently through experimental tests, confirming the accuracy of the proposed models. A techno-economic analysis indicated that a generation cost of Rs. 10.71 per unit would be associated with a fully agro-residue-based power plant, while less than Rs. 5.28–Rs. 5.31 would be the cost of generation per unit of electricity observed with 5% biomass co-firing in thermal plants. This study demonstrates that improved fuel quality and economic feasibility for biomass power generation can be achieved through strategic biomass blending and co-firing. These findings demonstrated that the blending of various biomass can be a viable strategy for enhancing the characteristics of pellet fuels on an industrial scale.

본 연구는 국유림 산림경영의 경제성을 실증적으로 분석하여, 경영 효율성을 평가하는 데 목적이 있다. 국유림 산림경영은 국가 주도로 장기간 이루어졌지만, 실질적인 경제적 성과에 대한 체계적인 검토는 부족한 상황이었다. 이에, 목재 생산 과정에서 발생하는 조림, 숲 가꾸기, 솎아베기, 수확 등의 주요 사업 비용과 판매 수익을 종합적으로 분석하였다. 분석은 산림청의 공식 지침 및 공시 자료를 기반으로 주요 수종별 시업 기준을 적용하여 단위 면적(ha)당 투입비용과 수익을 평가하였다. 분석 결과, 국유림 1ha를 경영하는 데에는 약 4,312만 원의 비용이 소요되는 것으로 추정되었다. 반면, 목재 판매를 통해 얻는 평균 수익은 ha당 약 313만 원에 불과하여, 국고 순손실이 약 93% 발생하였다. 이는 현재의 산림경영 구조로는 임업경영의 기본인 경제적 지속 가능성 확보가 불가능함을 보여준다. 특히, 국유림의 임목 매각 가격이 사유림보다 높게 책정됨에도 불구하고, 기대했던 수익성 확보에 실패한 점이 확인되었다. 또한, 국유림의 벌기령(50~60년)을 준수하더라도 입목축적과 매각단가가 기대치에 미치지 못하는 현실도 드러났다. 이러한 결과는 국유림 및 사유림 경영 정책의 전면적인 재검토와 체계적인 관리 전략 재수립의 필요성을 강하게 시사한다.

The use of big data needs to be emphasized in policy formulation by public officials in order to improve the transparency of government policies and increase efficiency and reliability of government policies. ‘Hye-Ahn’, a government-wide big data platform was built with this goal, and the subscribers of ‘Hye-Ahn’ has grown significantly from 2,000 at the end of 2016 to 100,000 at August 2018. Additionally, the central and local governments are expanding their big data related budgets. In this study, we derived the costs and benefits of ‘Hye-Ahn’ and used them to conduct an economic feasibility analysis. As a result, even if only some quantitative benefits are considered without qualitative benefits, the net present value, the benefit/ cost, and internal rate of return turned out to be 22,662 million won, 2.3213, and 41.8%, respectively. Since this is larger than the respective comparison criteria of 0 won, 1.0, and 5.0%, it can be seen that ‘Hye-Ahn’ has had economic feasibility. As noticed earlier, the number of analysis using ‘Hye-Ahn’ is increasing, so it is expected that the benefits will increase as time passes. Finally, the socioeconomic value gained when the results of analysis using ‘Hye-Ahn’ are used in policy is expected to be significant.

The objective of this study was to compare the feeding effects of imported timothy hay, domestic Italian ryegrass silage (IRGS) and IRG dried by hot-air dry system (IRGHDS) under basic total mixed ration (bTMR) on rumination activity, milk production, and milk composition in lactating dairy cows. Eighteen Holstein dairy cows were divided into three groups: control (bTMR + imported timothy hay), treatment 1 (bTMR + IRGS) and treatment 2 (TMR + IRGHDS) groups. The study was conducted over a total period of 24 days, including a 10 days adaptation period and a 14 days main experimental period. The results indicate body weight was not significantly different between the three groups (p>0.05), and rumination time was significantly higher in the treatment 1 group compared with the control group (p<0.001). Milk fat, protein, and lactose were not significantly different between the three groups (p>0.05), however, somatic cell counts were significantly lower in the treatment 1 group compared with the control group (p<0.001). As a result of the economic feasibility analysis, it is expected that feeding TMR using IRGS and IRGHDS will increase profit by 402.8 won/day and 331.4 won/day per cow compared to imported timothy hay. Therefore, IRGS and IRGHDS can be used as substitutes for imported timothy hay in feeding lactating dairy cows.

As an advanced study on the method of calculating the target revenue water ratio of local waterworks through the leakage component analysis method proposed by Kim et al. (2022), this study developed a model to calculate the achievable revenue water ratio within the specified project cost, the required project cost to achieve the specified target revenue water ratio, and the economically appropriate target revenue water ratio level by considering the leakage reduction cost and leakage reduction benefit for each revenue water ratio improvement strategy, and conducted an applicability evaluation of the developed model using actual field data. The procedure for calculating the target revenue water ratio of local waterworks considering economics proposed in this study consists of three stages: physical data linkage model construction, leakage component analysis, and economic analysis, and the applicability was evaluated for Zone H with branch type and the Zone M network type. As a result of the application, it was calculated that approximately 32.5 billion won would be required to achieve the target revenue water ratio of 70% in the Zone H, and approximately KRW 10.5 billion would be required to achieve the target revenue water ratio of 75% in the Zone M. If the business scale of Zones H and M was corrected to 10,000 ㎥/day of water usage, the required project cost for a 1% improvement in the revenue water ratio of Zone H was calculated to be 0.7642 billion won and 0.4715 billion won for Zone M.

Heavy bitumen scattered in the underground sedimentary layer is a kind of unconventional energy source, and by extracting it, a production well is excavated in the sedimentary layer and high-temperature and high-pressure steam is injected to reduce the viscosity of bitumen and recover it to the ground steam assisted method is applied. As a recovery method that uses the steam effect of the dilution effect of solvent injection, it is a recovery method that can increase thermal efficiency. In this study, the process system of the central processing facility(CPF) of the hybrid steam-solvent recovery method that injects solvent into the existing steam assisted method was analyzed, and the core facilities for each process were identified, and hybrid steam-solvent recovery compared to the existing steam assisted method. In the case of the method, it was evaluated that the amount of steam supply and all utility costs decreased according to the solvent injection.

This study is aimed to analyze fishermen’s perception and the economic feasibility of inland waters ranching project on the branches of Geum River. Analysis of fishermen’s perception on the branches of Geum River showed that fishermen had an affirmative response on the inland freshwater ranching project related issues such as fisheries resources enhancement, necessity of project, economic achievement as so on. The model of inland waters ranching project on the branches of Geum River is designed to fisheries resources enhancement, habitat compositiom, ecology tours, use and management of resources. The results of the economic feasibility of inland waters ranching project on the branches of Geum River were internal rate of return (IRR) was 18.43%, a benefit-cost ratio was shown to be 1.54, net present value (NPV) was 4,929 thousand won, which indicates the economic feasibility of inland waters ranching project.

This study is aimed to analyze the economic feasibility of yellowtail culture using the copper alloy net cage in Gyeongsangbuk-do. First of all, in order to evaluate the copper alloy net cage on yellowtail culture, I review the trend on the yellowtail culture industry and research the concept of copper alloy net cage. The copper-alloy net cage is now recognized as an advantages of its system stability, recycling, antibiosis and food safety. The results were summarized as follows: first, there was significant meaning of the profit model of yellowtail culture by the price difference. Second, I analyzed in the economic feasibility of yellowtail culture using the copper alloy net cage, internal rate of return (IRR) was 51.58%, a benefit-cost ratio was shown to be 2.27 and net present value (NPV) was 1,087,337 thousand won, which indicates the economic feasibility of yellowtail culture using the copper alloy net cage is profitable. Finally, in order to improve the economic valuation, it is necessary to focus more on the developing of technology and cost reduction strategy on the copper alloy net cage.

PURPOSES : In general, a high-performance concrete construction method is a method of loading mixed cement and other materials on a mobile mixer equipped with a concrete plant. However, the construction cost is high because the unit cost of the mixed cement is very high and the equipment usage fee of the mobile mixer is also high. To compensate for these drawbacks, a cellular spray concrete method was developed. This is a highly functional customized concrete construction method in which admixtures are added to high-flow concrete with cellular (air bubbles) added at the site and constructed through spraying. METHODS : Field workability evaluation using cellular concrete was carried out using a spray method in 2017 and an anti-foaming agent in 2018. The test construction section was set as a new road-pavement construction site. After construction, strength, durability characteristics, and void analysis were performed to compare the construction methods. The results of laboratory tests under optimal conditions were also compared to the on-field results. By comparing the indoor mixing and the on-field results, we analyzed whether there were any problems concerning the performance expression. The economic feasibility at the initial construction stage was analyzed by comparing the existing and the cellular concrete construction methods in terms of material cost and equipment usage fee. RESULTS : In the case of cellular spray concrete, construction through spraying is cumbersome, and the need to additionally use large equipment such as a pump car and compressor constitutes a disadvantage. However, the most relevant feature is that it can be constructed not only on the floor, but also on a slope. In the case of cellular concrete with an antifoaming agent, it was possible to quickly produce high-performance concrete using on-site remixing equipment. By supplying materials to the pouring surface using a conveyor, smooth construction and construction in narrow spaces were also possible. CONCLUSIONS : The cellular concrete method allows the immediate on-site production of high-performance concrete, and it is possible to selectively apply spray construction, antifoaming agent construction, etc.

This study aimed to analyze the economic feasibility of the reduction of working safety accidents in stow net fishery through the prevention education to fishing crews. The benefit was evaluated by estimating insurance payment amount that was reduced through prevention education. The decreasing rate of working safety accidents was presumed to follow the experience in Japan. The cost was assumed as the cost of textbook development. Results indicated that IRR was estimated to be 79.9% in case of scenario assuming no additional operating costs while IRR was 56.3% in case of scenario assuming 10% additional operating costs. In addition, the economic feasibility would be secured when annual operating costs increased to 274 million won according to the result of sensitivity analysis.

This study aimed to analyze the profitability and economic feasibility of hairtail trolling line gear that was developed for the last 3 years (2015-2017). The new fishing gear technology development was accomplished to solve the current problem of fishermen shortage in hairtail targeting fisheries in Jeju region. Results indicated that the profitability of developed hairtail trolling line fishery was estimated to be 36.1 % which would be higher than that of other hairtail targeting fisheries in Jeju region. In addition, as an economic feasibility, the net present value and the internal rate of return of a 20-year cash inflow and outflow were evaluated to be 400.2 million won and 66.9 %, respectively. However, sensitivity analyses of main variables showed that the profitability and economic feasibility would be vulnerable to catch amount and market condition changes.

This paper aims to analyze the economic feasibility and investigate the possibility of elastic seismic design of wind-designed highrise concentrically braced frames considering change of mechanical properties of Korean steel under the strong wind and the low seismicity in Korea. To this end, first, highrise concentrically braced frames were designed considering strong wind load. And then, analyses of the economics of them were performed. The seismic performance evaluation of wind-designed highrise buildings was conducted using the response spectrum analysis procedure. Analysis results show that it is possible to save up to approximately 90% of the amount of steel on the 10% increase in steel strength without serviceability. However, with serviceability, the design sectional area of the steel with relatively high strength tends to increment considerably because of the lateral stiffness due to reduction of the inertia moment and so on. This point might apply to limitation of the steel with high tensile yield strength.