• Korean Chemical Engineering Research
• /
• v.50 no.3
• /
• pp.479-491
• /
• 2012

In this paper we performed evaluation of the economics of a district heating system (DHS) consisting of energy suppliers and consumers, heat generation and storage facilities and power transmission lines in the capital region, as well as identification of optimal operating conditions. The optimization problem is formulated as a mixed integer linear programming (MILP) problem where the objective is to minimize the overall operating cost of DHS while satisfying heat demand during 1 week and operating limits on DHS facilities. This paper also propose a new forecasting model of the system marginal price (SMP) using past data on power supply and demand as well as past cost data. In the optimization, both the forecasted SMP and actual SMP are used and the results are analyzed. The salient feature of the proposed approach is that it exhibits excellent predicting performance to give improved energy efficiency in the integrated DHS.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.8
• /
• pp.75-81
• /
• 2008

Water treatment study employing plasma is thoroughly examined in the following paper. The research using water plasma torch showed superior results in terms of economical and energy efficiency due to the substantial reduction of electric power. A comparison of streamer and arc discharge phenomena taken place in water was put under close scrutiny. Dyeing wastewater exposed to the plasma treatment was sampled and analyzed for relative dissolved ozone concentration, hydrogen peroxide, as well as the color removal efficiency. It was found that streamer discharges is more effective than arc discharge in growth of $H_2O_2$ and $O_3$ by plasma chemical constituents, though plasma torch had small oxidation reagents selectivity. Thus, streamer discharges, due to the efficient plasma-chemical reactions environment, proved to be more efficient compare to the thermal arc plasma loading.

• Journal of the Korean Institute of Gas
• /
• v.4 no.3 s.11
• /
• pp.26-32
• /
• 2000

Because of the continuous growth of energy consumption, and also the tendency to site power lines and pipelines along the same routes, the close proximity of high voltage structures and metallic pipelines has become more and more frequent. Moreover, normal steady state and fault currents become higher as electric networks increase in size and power Therefore, there has been and still is a growing concern(safety of people marking contact with pipeline, risk of damage to the pipeline coating, the metal and equipment connected to pipeline, especially cathodic protection system) about possible hazards resulting from the influence of high voltage power system on metallic structures(gas pipeline, oil pipeline and water pipeline etc.). Therefore, we analyze the interference problems when the gas pipeline is buried with power cable in the same submarine tunnel. This paper present the results of the study about interference mechanism, AC corrosion limitation of safety voltage and analysis of induction voltage.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.5
• /
• pp.3633-3642
• /
• 2015

Single-base propellants contain a single energetic component: nitrocellulose. Accurate predictions of propellant shelf-life should result in cost savings in terms of human and material resources. This study derived an optimized kinetic model reaction order that described stabilizer consumption and estimated propellant shelf-life. High temperature accelerated aging tests gave an optimum reaction order value of 1.15481, from which the minimum standard error of a linear regression estimate of 16.284 was obtained. At normal storage temperature of $21-30^{\circ}C$, propellants should have a safe shelf-life of 140 years, and a minimum of 35 years. It is necessary to consider the temperature range in ammunition storage areas to predict propellant shelf-life more accurately.

• Journal of Korean Society on Water Environment
• /
• v.32 no.2
• /
• pp.197-204
• /
• 2016

The growth of the algae strain Chlorella vulgaris under mixotrophic conditions in the presence of saccharified acorn-starch (acorn-glucose) was evaluated with the objective of increasing biomass growth and triacylglycerols (TAGs) content. The results indicated that 81.3% of starch was converted to glucose in acorns. C.vulgaris algal strains grown with acorn-glucose produced higher biomass and TAGs content than with autotrophic growth. The highest biomass production and TAGs content with 3 g/L acorn-glucose were 12.44 g/L and 32.9%, respectively. Biomass production with 3 g/L acorn-glucose was 16.4 fold higher than under autotrophic growth condition. These findings suggested that 3 g/L acorn-glucose is economic and efficient for biomass production/productivity and TAGs content of microalgae. This study provides a feasible way to reduce the cost of bioenergy production from microalgae.

• Journal of Navigation and Port Research
• /
• v.32 no.6
• /
• pp.465-471
• /
• 2008

As the excessive competition between container terminals has been deepening, not only productivity, but also cost economic of the terminals has been raised. With regard to this, the competitiveness of the terminals is limited because of inefficiency operation of transfer crane(T/C) which needs large amount of energy consumption. Therefore, it is possible that the improvement in the T/C operation leads to saving cost for resources and energy as well as increasing the productivity of the terminals. This study provides 'the K-Means Clustering based Optimized Decision Model for Transfer Crane Operation', referring to 'RFID & RTLS based Port Logistics Initiative' of Ministry of Land, Transportation and Maritime Affairs and estimates the efficiency through simulating.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.2
• /
• pp.89-96
• /
• 2016

The High Efficiency Video Coding (MPEG-H HEVC/ITU-T H.265) is the newest video coding standard which has the quadtree-structured coding unit (CU). The quadtree-structure splits a CU adaptively, and its optimum CU depth can be determined by rate-distortion optimization. Such HEVC encoding requires very high computational complexity for CU depth decision. Motivated that the blob detection, which is a well-known algorithm in computer vision, detects keypoints in pictures and decision of CU depth needs to consider high frequency energy distribution, in this paper, we propose to utilize these keypoints for fast CU depth decision. Experimental results show that 20% encoding time can be saved with only slightly increasing BDBR by 0.45% on all intra case.

• Journal of Korea Port Economic Association
• /
• v.25 no.3
• /
• pp.361-384
• /
• 2009

This study aims to analyse the current conditions of transport demand and its environmental problems in Gwangyang Port(GP), and to suggest crucial directions for Gwangyang Green Port(GGP) in Korea. This study consists of three main sections: concept of green growth and green port; the analysis of transport demand and environment situations in GP; policy directions for GGP. This study is mainly conducted by a literature review of related papers, an analysis of secondary data & papers, and interviews with port experts. This study presents important policy directions for successfully managing GGP in Korea as follows: modal shifts plan for green transport and logistics system in GP; energy-saving techniques in GP's berth operation; the application of environmentally friendly port operation methods in GP; construction of GP waterfront facilities; environmentally friendly disposal of maritime waste matters; establishment and implementation of port environment master plan. This study will make a big contribution to the building of green port policy and the providing of professional informations to government officials.

• Journal of Advanced Navigation Technology
• /
• v.25 no.4
• /
• pp.267-272
• /
• 2021

The end of the ROK-U.S. missile guidelines opened up the possibility of developing space launch vehicles for various platforms based on air and sea. In particular, the air-based space launch vehicle is an essential space power projection capability compared to the ground-based space launch vehicle in consideration of the geographical location of the Korean Peninsula, such as the deployment of various satellite orbits and the timely launch of satellite. In addition, compared to the ground-based launch vehicle, the cost reduction effect is large, and it has the merit of energy gain because it can be launched with the advantage of the aircraft's altitude and speed. Therefore, in this paper, the necessity of air-based space launch vehicle in the strategic environment of the Korean Peninsula is clearly presented, and through technology trend analysis of various air launch vehicle, the three methods are proposed to have the most efficient air-based space launch vehicle capability in the Korean situation.

• Smart Media Journal
• /
• v.13 no.6
• /
• pp.24-34
• /
• 2024

If the future can be predicted from network traffic data, which is a time series, it can achieve effects such as efficient resource allocation, prevention of malicious attacks, and energy saving. Many models based on statistical and deep learning techniques have been proposed, and most of these studies have focused on improving model structures and learning algorithms. Another approach to improving the prediction performance of the model is to obtain a good-quality data. With the aim of obtaining a good-quality data, this paper applies a dense sampling technique that augments time series data to the application of network traffic prediction and analyzes the performance improvement. As a dataset, UNSW-NB15, which is widely used for network traffic analysis, is used. Performance is analyzed using RMSE, MAE, and MAPE. To increase the objectivity of performance measurement, experiment is performed independently 10 times and the performance of existing sparse sampling and dense sampling is compared as a box plot. As a result of comparing the performance by changing the window size and the horizon factor, dense sampling consistently showed a better performance.