Port operational efficiency is considered as one of the most important competitive factors and plays a critical role in the port development all over the world, especially container ports. Haiphong Port, which is in the northern of Vietnam, is planned to become one of the national and regional ports. To do this objective, it is important to analyse the operational efficiency of its container terminals. The paper aims to comparatively analyse the operational efficiency of 16 container terminals in Haiphong Port from 2016 to 2022 by basic and Malmquist DEA models. With 112 observations collected and calculated in R software, DEA models have five inputs (container yard area, number of quay crane, berth draft, berth length, labour force) and one output (annual cargo throughput). Consequently, Hai An, Tan Vu, and Vip Greenport are more efficient terminals over the 7-year period, whereas Transvina and MIPEC have lower efficiency. Paper contributions are the literature review about port operational efficiency and references to propose resolutions in next author’s research as well as masterplans to develop Vietnam seaport’s system. Besides, the limitations are discussed as the number of observations and environmental factors in ports.

현재의 해양산업의 기술은 스마트 선박 및 자율운항선박 등의 개발과 같은 자율화 및 지능화와 환경규제의 강화에 맞추어 선 박의 운항 효율성을 개선하는 친환경 선박을 위한 기술이 함께 개발되고 있다. 이러한 흐름에 맞추어, 세계각국에서는 선박의 안전운항을 보장하는 선에서 선박운항효율을 극대화하기 위해 다양한 방식으로 노력하고 있다. 본 연구에서는, 현존하는 선박운항효율 개선 기술이 운항 당시의 기상환경, 선박조종 등의 선박운항상태를 실시간으로 반영하지 못하는 문제를 개선하기 위해, 선박에서 수집한 선박운항데 이터를 활용하여 실시간 선박운항효율 분석모델을 개발하고자 한다. 본 연구의 실시간 선박운항효율 분석모델은 연료소모를 기준으로 판 단한 선박운항효율과 당시의 선박운항상태를 감안하여 판단한 선박운항효율을 비교하여, 식별된 선박운항효율의 타당성을 확인할 수 있 는 모델이다. 분석의 주요 내용은 대상선박의 선정과 선박운항데이터의 수집, 선박운항효율 특성과 선박운항상태 특성의 구분, 그리고 이 를 활용한 분류모델의 개발을 포함한다. 연구의 결과는 기존의 선박운항효율과 항해 당시 선박운항상태를 감안한 운항효율을 제시하여 선박 운항자의 의사결정을 지원하여 운항효율을 개선하고자 한다.

Shipping companies are key components of the logistics industry, which is extremely significant in enhancing the country's comprehensive national power and promoting global trade development. In the context of the implementation of the new development pattern strategy in China and the impact of the global novel coronavirus (COVID-19), this paper takes 22 Chinese shipping listed companies as the research object and analyses the operational efficiency of them from 2011 to 2020 based on the Super-SBM DEA Model and Window DEA Model. Factors affecting the efficiency are further analyzed with the Tobit model. The research conclude that the operational efficiency of Chinese shipping companies as a whole shows a steady increase from 2011 to 2020. Although most of them are in a relatively effective operation state, fewer are absolutely effective companies. Besides efficiency among companies differs obviously, which indicates the potential of further improvement and promotion. What’s more, factors such as current economic development level, enterprise size, human resources quality and enterprise turnover speed have significant positive correlation to the operation efficiency of Chinese shipping listed companies, which is significant to improve the operation efficiency of Chinese shipping companies.

COVID-19가 전 세계를 강타하면서 각 국가는 대혼란에 빠졌다. 전 세계 화물교역은 80 % 이상이 해상운송을 통해 이루어지고 있어 화물과 여객을 포함한 해상운송업은 COVID-19의 큰 영향을 받는 산업으로 예측되었다. 따라서 본 연구의 목적은 코로나 팬데믹 (Coronavirus Pandemic) 발생 전후로 아시아 주요 항만 컨테이너 항구의 팬데믹 전후 운영효율성을 분석하는 것이다. 항만의 운영효율성을 분석하기 위해서 자료포락분석(DEA)을 이용하였다. 본 연구의 분석 기간은 5년(2016~2020년)으로 2016년, 2017년, 2018년, 2019년을 코로나 이전으로 하고, 2020년을 포스트 코로나 시대로 설정하였다. 또한, 분석 대상으로는 아시아 상위 10개 항구 중 동종 DMU의 DEA 요건을 충족시킨 상하이, 광저우, 선전, 닝보-저우산, 부산 및 싱가포르 총 7개 항구를 선택하였다. DEA의 CCR 및 BCC 모델의 결과는 몇 가지 비효율성이 확인되었음에도 COVID-19 팬데믹 발생 시점에서 몇 개월 이후부터는 전반적으로 운영효율성이 코로나 이전 몇 년 동안보다 상대적으로 높았음을 확인하였다. 하지만 일부 항만 (부산, 광저우)의 경우에는 더욱 나은 운영효율성을 위해서 항만의 규모와 운영의 기술적 능력 등을 제고 할 필요가 있다.

Evaluating the operational efficiency of electric vehicle charging stations (EVCSs) is important to understand charging network evolution and the charging behavior of electric vehicle users. However, aggregation of efficiency performance metrics poses a significant challenge to practitioners and researchers. In general, the operational efficiency of EVCSs can be measured as a complicated function of various factors with multiple criteria. Such a complex aspect of managing EVCSs becomes one of the challenging issues to measure their operational efficiency. Considering the difficulty in the efficiency measurement, this paper suggests a way to measure the operational efficiency of EVCSs based on data envelopment analysis (DEA). The DEA model is formulated as constant returns of output-oriented model with five types of inputs, four of them are the numbers of floating population and nearby charging stations, distance of nearby charging stations and traffic volume as desirable inputs and the other is the traffic speed in congestion as undesirable one. Meanwhile, the output is given by the charging frequency of EVCSs in a day. Using real-world data obtained from reliable sources, we suggest operational efficiencies of EVCSs in Seoul and discuss implications on the development of electric vehicle charging network. The result of efficiency measurement shows that most of EVCSs in Seoul are inefficient, while some districts (Nowon-gu, Dongdaemun-gu, Dongjak-gu, Songpa-gu, Guro-gu) have relatively more efficient EVCSs than the others.

Protecting and preserving the natural and environmental treasures of Jeju Island is, eventually, the collective responsibility of the people of Jeju, all levels of the government, corporate and the environmental NGO sectors. Jeju Island has a vibrant environmental NGO sector with about 80 NGOs providing a variety of active environmental services. All efforts and services to conserve the environment of Jeju Island for the benefits of future generations need to be galvanized within the overarching environmental governance where all three sectors actively participate and make collective decisions within the three key elements of sustainable development: people, planet & profit. The key ingredient for promoting networking and collaborative opportunities between environmental NGOs, government entities and corporations is to improve their trust on one another. Given the current status of environmental NGOs - governments - corporations relations, it will take time to develop such trust, but if small measures are undertaken, mutual understanding & respect between the leaders of NGOs, government and corporations will grow and eventually result in mutual trust.

Membrane filtration process is an advanced water treatment technology that has excellently removes turbidity and microorganisms. However, it is known that it has problems such as low economic efficiency and the operating stability. Therefore, this study was to evaluate on the economical feasibility and operational stability comparison of membrane and sand filtration process in Im-sil drinking water treatment plant. For the economic analysis of each process, the electricity cost and chemical consumption were compared. In the case of electric power consumption, electricity cost is 68.67KRW/㎥ for sand filtration and 79.98KRW/㎥ for membrane filtration, respectively. Therefore, membrane filtration process was about 16% higher than sand filtration process of electricity cost. While, the coagulant usage in the membrane filtration process was 43% lower than the sand filtration process. Thus, comparing the operation costs of the two processes, there is no significant difference in the operating cost of the membrane filtration process and the sand filtration process as 85.94KRW/m3 and 79.71KRW/m3 respectively (the sum of electricity and chemical cost). As a result of operating the membrane filtration process for 3 years including the winter season and the high turbidity period, the filtrated water turbidity was stable to less than 0.025 NTU irrespective of changes in the turbidity of raw water. And the CIP(Clean In Place) cycle turned out to be more than 1 year. Based on the results of this study, the membrane filtration process showed high performance of water quality, and it was also determined to have the economics and operation stability.

PURPOSES: The goal of this study is to analyze the operational efficiencies of special roundabouts using simulated programs. METHODS: This study primarily focuses on comparing the delays and traffic flow disturbances occurring at special roundabouts. In this study, the operational efficiencies of 450 scenarios (5 roundabout types × traffic volumes × directional ratios × measures) are analyzed according to the corresponding delays and traffic flow disturbances using VISSIM and SSAM. RESULTS : The main results are as follows: 1) the Hamburger roundabouts are determined to yield the least common-type delays, 2) the amount of delays at Turbo and Flower roundabouts with respect to relatively increased right-turn-type delays, in addition to the amount of delays at the Left-turn slip-lane roundabout with respect to relatively increased left-turn-type delays, are found to be reduced as compared to the common-type delays. Lastly, common- and increased right-turn-type traffic flow disturbances at the Turbo roundabout and increased left-turntype traffic flow disturbances at the Left-turn slip-lane roundabout are determined to be the most infrequent. CONCLUSIONS: This study comparatively analyzes five roundabout types: standard, Flower, Turbo, Hamburger, and Left-turn slip-lane. The effectiveness of roundabouts can increase according to given traffic volume, directional ratio, and measure of effectiveness.

PURPOSES: Regional offices of the Ministry of Land, Transport and Maritime Affairs use a computerized system called KAMIS so as to manage road equipment systematically. Road agencies can record number of operating days by equipment, actual working hours, accumulated operating hours (or distance) by equipment, and operating cost. However, KAMIS does not provide critical information, although it is strongly related to efficient road management equipment operation. In other words, road agencies do not know whether they have sufficient equipment to handle their actual work. METHODS: Therefore, this study suggests a methodology to evaluate for operational efficiency of road management equipment using analytical hierarchy process(AHP). First of all, estimated weights related criteria can be produced by AHP, and then use operational history by pieces of equipment. RESULTS: Results show that importance of management work can differ from weather conditions through five areas. CONCLUSIONS: Commonly, this results can imply to help save money for the purchase and maintenance of road management equipment, and they would improve the functional performance of KAMIS.

DEA모형에 의한 운영효율성 분석결과로부터 얻을 수 있는 시사점은 다음과 같다. 정부의「산지유통종 합평가」제도의 개선을 통해 사업실적 위주의 규모화ㆍ전문화ㆍ조직화에 초점을 맞춰 이루어져온 것을 경 영효율성 위주로 전환해야 할 것이다. 산지유통센터의 목적도 농산물의 부가가치를 높이는 것이고 이를 평가할 수 있는 지표를 개발하여 평가함으로써 농산물 산지유통센터 구성원들에게 실질적인 인센티브와 다양한 양질의 서비스를 제공할 수 있도록 해야 할 것이다. 그리고 농산물 산지유통센터가 종합평가에 경 영의 중점을 두고 있기 때문에 이를 개선, 보완하기 위해 유통부가가치를 평가할 수 있는 지표의 개발, 평가에 대한 고객만족도 지표의 개발, CRM(Customer Relationship Management)시스템 도입을 통한 고객관계 유지 실적을 평가할 수 있는 지표의 개발 등도 추진되어야 할 것이다.

지금까지 컨테이너 자동화 터미널의 설계 및 운영 모델 개발은 주로 수출입 화물의 양적·하 기능에 특화된 서구 항만을 대상으로 수행되었기 때문에, 부산항처럼 다양한 On-Dock 서비스가 요구되는 컨테이너 항만에서는 자동화 터미널의 도입과 운영에 많은 제약이 따른다. 이에 본 연구의 목적은 부산항을 사례로 현재 컨테이너 물동량 구조와 터미널 내부 운영 특성을 진단하고, 기존 자동화 터미널 운영 모델의 부 분적인 변경을 통해 효과적인 공컨테이너 관리와 함께 터미널 운영비용을 절감하는 방안을 제시하는 것이다. 기존 수직 배열 자동화 컨테이너 터미널에 ‘인터체인지 이송 모델’을 적용하여 시뮬레이션 한 결과, 수정된 운영 모델은 구내 이송장비를 추가로 투입해야 하는 불리함에도 불구 하고 기존 운영 모델 대비 최대 22%의 TAT 단축과 함께 연간 터미널 매출의 9.4%에 달하는 운영비용 절감이 가능한 것으로 나타났다.

This study was carried out to examine the improvement plan by analyzing the characteristics of imported wastes, operation rate, and benefits of energy recovery for incineration facilities with a treatment capacity greater than 50 ton/ day. The incineration facility capacity increased by 3,280 tons over 15 years, and the actual incineration rate increased to 2,783 ton/day. The operation rate dropped to 76% in 2010 and then rose again to 81% in 2016. The actual calorific value compared to the design calorific value increased by 33.8% from 94.6% in 2002 to 128.4% in 2016. The recovery efficiency decreased by 29% over 16 years from 110.7% to 81.7% in 2002. Recovery and sales of thermal energy from the incinerator (capacity 200 ton/day) dominated the operation cost, and operating income was generated by energy sales (such as power generation and steam). The treatment capacity increased by 11% to 18% after the recalculation of the incineration capacity and has remained consistently above 90% in most facilities to date. In order to solve the problem of high calorific value waste, wastewater, leachate, and clean water should be mixed and incinerated, and heat recovery should be performed through a water-cooled grate and water cooling wall installation. Twenty-five of the 38 incineration facilities (about 70%) are due for a major repair. After the main repair of the facility, the operation rate is expected to increase and the operating cost is expected to decline due to energy recovery. Inspection and repair should be carried out in a timely manner to increase incineration and heat energy recovery efficiencies.

Recently, the air quality issue came to the fore to the occupants of indoor areas with the detection of a large amount of indoor air pollutants such as formaldehyde that causes headache and atopic dermatitis. In order to address this issue, the use of indoor air purifying plants is considered positively as an ecological improvement option. However, the objective performance verification on indoor air-conditioning air volume has not been sufficient. This study aims to verify possible linkage with a building’s air conditioning equipment in order to optimize indoor air-conditioning effects by vegetation bio-filters. To this end, 4 different types of air filter material and AHU (Air Handling Unit) system were linked under air conditions of total wind volume of 400, 600, 800, 1,000 CMH and pressure loss by material was monitored objectively. Finally, material-specific power consumption for system operation was calculated to review energy efficiency. As for pressure loss by material, in terms of total wind volume of 800±1.8 CMH, Pre filter was lowest at –11.69 mmAq and LMF-based vegetation mat was highest at –219.94 mmAq. Based on this, as for material-specific power consumption, the Pre filter, which has the lowest pressure loss, was expected to have power consumption 94.7% lower than the LMF-based vegetation mat.