• Title/Summary/Keyword: Efficiency scope

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A Study on the Optimal Method of Eco-Friendly Recycling through the Comparative Analysis of the Quantitative Calculation and Scope of Recycling

  • Seung-jun WOO;Eun-gyu LEE;Chul-hyun NAM;Kang-hyuk LEE;Woo-Taeg KWON;Hee-Sang YU
    • Journal of Wellbeing Management and Applied Psychology
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    • v.7 no.3
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    • pp.1-11
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    • 2024
  • Purpose: The purpose of this study is to present an efficient emission reduction ratio of plastic to reduce carbon dioxide, the main cause of greenhouse gases. Research design, data and methodology: This study calculated the absolute value of carbon dioxide by setting an equation through the emission coefficient using the US EPA's WARM model. Results: In the recycling ratio of 70%, it was found that the energy recovery ratio was 15.6%, which was the energy recovery ratio without generating carbon dioxide. When carbon dioxide is generated by changing plastic waste emissions, optimal efficiency is achieved by reducing emissions by 10% to 30% of energy recovery ratio, 20% to 50% of energy recovery ratio, and 30% to 80% or more of energy recovery ratio. Conclusions: The recycling rate should be set at a minimum of 70%, so that a carbon dioxide-free energy recovery rate could be obtained during the recycling process, supporting an eco-friendly basis for environmental policies aimed at this rate. In addition, it was possible to suggest that it is essential to reduce emissions by at least 30% for eco-friendly recycling measures that can achieve both economic and environmental feasibility in the energy recovery process through incineration during recycling in Korea.

A study on characteristics of SOFC/GT system for the supply gas flow rates (공급가스 유량에 따른 SOFC/GT 시스템 특성에 관한 연구)

  • Park, Sang-Kyun;Lee, Joo-Hee;Park, Geong-Dae;Choi, Jae-Hyuk
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.7
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    • pp.765-772
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    • 2015
  • In this research, the characteristics of SOFC/GT (Solid Oxide Fuel Cell/Gas Turbine) system temperature, stack power and system efficiency for flow rates of air, CH4 and water supplied to SOFC stack have been investigated. The temperature of the gas supplied to cathode and anode of SOFC stack in the SOFC/GT system are maintained by utilizing exhaust gas without the addition of external heat source. As a result, within the scope of this study, temperatures of gas supplied to cathode and anode of SOFC stack were maintained at 1000 (K) by utilizing the exhaust gas of the SOFC/GT system without the addition of external heat source. The system efficiency is increased with increase of air flow rate supplied to the stack and with decrease of $CH_4$ flow rate supplied to the stack. In addition, it can be found that the flow rate of the exhaust gas supplied to the turbine had a significant effect on the system efficiency. And the efficiencies of SOFC stack and SOFC/GT system depending upon various operating conditions of the SOFC/GT system is 51~57% and 57~73%, respectively.

The Productivity Analysis on Regional Logistics Warehouse (지역별 물류창고의 생산성 분석)

  • Park, Hong-Gyun
    • Journal of Korea Port Economic Association
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    • v.28 no.1
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    • pp.143-157
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    • 2012
  • By strengthening the market control and expanding the networks, providers of global logistics are expanding their service scope. The warehouses connect networks to internal and external warehouses by using logistics providers. The paper focuses on analyzing the efficiency of warehouses on each district. Therefore, the study classifies the factors which specify the efficiency of a total logistics of warehouse industry and warehouses' employees and the number of warehouses on district. Furthermore, the most recently published reports by National Center for Statistics in 2012 was used in order to guarantee credibility of the study. This study utilizes five years of materials, which are from 2005 to 2009. By applying SBM (Slack Based Measure), DEA Window model, and the Malmquist productivity model, the trend in efficiency and stableness were analyzed. The principal purpose of the paper is evaluating the efficiency. Also, analyzing its determinants and illustrating a long-term relationship between the regional warehouses and annual turnover of the warehouses were used as output measures. In addition, the number of warehouses of each region, employees, warehouses equipments, and the Logistics Warehouses Providers were used as input measurements. As a result, Malmquist productivity model and annual stableness has shown a continuous increasing. Ultimately, to be approved as product of Korea, a new stratiges that meet the standards and Rules of Origins by FTA should be developed. Therefore, there must be a development that takes regional characteristics into consideration.

Analysis of VoLTE Charge Reduction under VoLTE Growth (VoLTE 활성화에 따른 요금 인하 여력 분석)

  • Lee, Sang-Woo;Jeong, Seon-Hwa
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.1
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    • pp.92-100
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    • 2016
  • It is informed that the Voice over LTE(VoLTE) which serves voice and message on IP networks is better in terms of economies of scale than the legacy voice service on 2G/3G circuit-switched networks because of its technological and cost efficiency. In addition, services of voice and data are running on a single LTE network and as a result VoLTE has the more economies of scope. But, there is no study about how much technology-efficiency VoLTE has compared to circuit-based voice service and how much voice charge can be reduced as VoLTE grows up. This paper analyzes empirically cost-efficiency of VoLTE against circuit-based voice service and quantifies the reduction of voice charge as 2G/3G voice traffic shifts to VoLTE. The results describe the first is that the average cost of the total voice traffic rises shortly just after the investment of LTE network for providing VoLTE but it will soon have a capacity available to reduce the charge due to VoLTE's outstanding cost efficiency on the assumption that voice traffic is fixed, and the second is that the charge can be cut to 60% of the current rate in case of all the voice traffic moves to VoLTE. The latter proves partially the validation of data-focusing pricing plan. Our results are expected to become basic data for network operators' establishing pricing strategies and for policy makers' inducing price cutting.

Physiological Response of the Pearl Oyster, Pinctada fucata martensii, to Low Water Temperature: a Preliminary Study for Indoor Overwintering (진주조개 Pinctada fucata martensii의 실내월동을 위한 저온노출에 따른 생리적 변화)

  • Lee, Jeong-Mee;Lee, Sang-Won;Cho, Sang-Man
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.43 no.1
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    • pp.54-62
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    • 2010
  • With the aim of developing and indoor overwintering technique for Pearl oyster, Pinctada fucata martensii, the metabolic rates of young oysters (52.4-83.0 mm in shell length) were measured for 2 weeks at water temperatures of 8, 10, 12, and $14^{\circ}C$. The filtration rate (FR) ranged 0 to $4.84\;L\;h^{-1}gDW^{-1}$ (mean, $0.02{\pm}0.06 $ to $3.12{\pm}1.45$), with significant changes observed over thme except for the case of a water temperature of $14^{\circ}C$. Respiration rate (R) ranged from 0 to $2.370\;mgO2\;h^{-1}gDW^{-1}$ (mean, 0 to $1.77{\pm}0.37$), with significant respiratory disorders observed at temperatures below $12^{\circ}C$; in contrast, the rate increased on the $14^th$ day of the experiment in the case of a temperature of 14$^{\circ}C$. No significant difference was observed among the different water temperatures in terms of excretion rate (E) or absorption efficiency (Abs.eff), except for a significant decrease in aerobic metabolism in the case of water temperature of $8^{\circ}C$. The estimated scope for growth (SFG) ranged from -9.1 to $126.9\;J\;h^{-1}gDW^{-1}$ (mean. $-4.1{\pm}2.6$ to $82.85{\pm}42.6$). A significant energy Joss was found at $8^{\circ}C$, with negative SFG observed throughout the experiment and a gradual energy decrease observed over time at water temperatures of $10^{\circ}C$ and 120C. However. SFG remained positive throughout the experiment in the case of $14^{\circ}C$. The estimated minimum energy requirement, assessed from energy expenditure, is $8.00-34.24\;J\;h^{-1}gDW^{-1}$ (mean, $17.67{\pm}6.17$). In conclusion, the lowest temperature suitable for indoor overwintering is above $14^{\circ}C$.

A study on unmanned watch system using ubiquitous sensor network technology (유비쿼터스 센서 네트워크 기술을 활용한 무인감시체계 연구)

  • Wee, Kyoum-Bok
    • Journal of National Security and Military Science
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    • s.7
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    • pp.271-303
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    • 2009
  • "Ubiquitous sensor network" definition is this-Someone attaches electro-magnetic tag everything which needs communication between man to man, man to material and material to material(Ubiquitous). By using attached every electro-magnetic tag, someone detects it's native information as well as environmental information such as temperature, humidity, pollution and infiltration information(Sensor). someone connects it realtime network and manage generated information(Network). 21st century's war is joint combined operation connecting with ground, sea and air smoothly in digitalized war field, and is systematic war provided realtime information from sensor to shooter. So, it needs dramatic development on watch reconnaissance, command and control, pinpoint strike etc. Ubiquitous computing and network technologies are essential in national defense to operate 21st century style war. It is possible to use many parts such as USN combined smart dust and sensor network to protect friend unit as well as to watch enemy's deep area by unmanned reconnaissance, wearable computer upgrading soldier's operational ability and combat power dramatically, RFID which can be used material management as well as on time support. Especially, unmanned watch system using USN is core part to transit network centric military service and to get national defense efficiency which overcome the dilemma of national defense person resource reducing, and upgrade guard quality level, and improve combat power by normalizing guardian's bio rhythm. According to the test result of sensor network unmanned watch system, it needs more effort and time to stabilize because of low USN technology maturity and using maturity. In the future, USN unmanned watch system project must be decided the application scope such as application area and starting point by evaluating technology maturity and using maturity. And when you decide application scope, you must consider not only short period goal as cost reduction, soldier decrease and guard power upgrade but also long period goal as advanced defense ability strength. You must build basic infra in advance such as light cable network, frequency allocation and power facility etc. First of all, it must get budget guarantee and driving force for USN unmanned watch system project related to defense policy. You must forwarded the USN project assuming posses of operation skill as procedure, system, standard, training in advance. Operational skill posses is come from step by step application strategy such as test phase, introduction phase, spread phase, stabilization phase and also repeated test application taking example project.

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Active and Cognitive Evaluating of the Recreational Spaces in Natural Settings (자연휴양공간(自然休養空間)의 이용행동(利用行動) 및 인지적(認知的) 평가(評價))

  • Kim, Bum Soo;Chung, Yoon Soo
    • Journal of Korean Society of Forest Science
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    • v.83 no.4
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    • pp.429-440
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    • 1994
  • This study attempt to evaluate the recreation space(two patterns ; one is open space ; forest, water-front space and free open space, the other recreational fercilities) located in the natural area based on clarifying the relationship between the physical conditions of these spaces and human response(users' cognitive evaluation and users' activity pattern). On this standpoint it was proceeded to analyses of the information which was collected by interviews to users who were in this open space at the natural park of Osaka Prefecture. Through this study, the results were summarized as follows ; 1) Forest and waterfront space are considered to be a basic factor of the composition in natural recreation areas. There was difference on the recreational value depending on condition of forest composition. The hardwood-forest apparently high in its efficiency. 2) Free open space is a definite recreational space surely wide in its scope of active of recreational use. The site should be setted up considering the plants conditions around and geographical features according to the recreational activities, and the ground cover should be well controlled. 3) The recreational facilities in natural settings such as the sightseeing tower, the insect display hall, and the camp site appeared to produce low value as a recreational space. It was desirable that recreational activities be allowed within the scope. Consequently, we should carefully consider environmental capacity and landscape to designing these spaces 4) Traditional history and cultural properties are recognized as part of recreational resource as and also as essence of the compositions. So continuos care and proportion of history and cultural properties should be guaranteed.

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Analyses of Expert Group on the 4th Industrial Revolution: The Perspective of Product Lifecycle Management (4차 산업혁명에 관한 전문가그룹 분석: 제품수명주기관리의 관점에서)

  • Wongeun Oh;Injai Kim
    • Journal of Service Research and Studies
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    • v.10 no.4
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    • pp.89-100
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    • 2020
  • The smart factory is an important axis of the 4th industrial revolution. Smart factory is a system that induces the maximum efficiency and effectiveness of production using the IoT and intelligent sensing systems. The product lifecycle management technique is a method that can actively reflect the consumer's requirements in the smart factory and manage the entire process from the consumer to the post management. There have been many studies on product lifecycle management, but studies on how to organize product lifecycle management knowledge domains in preparation for the era of the 4th industrial revolution were insufficient. This study analyzed the opinions of a group of experts preparing for the 4th industrial revolution in terms of product lifecycle management. The impact of the 4th industrial revolution on the detailed knowledge areas of product lifecycle management was investigated. The changes in product lifecycle management were summarized using a qualitative data analysis technique for a group of experts. Based on the opinions of experts, the product lifecycle management, which consists of a total of 30 detailed knowledge areas, was prepared to supplement or prepare for the 4th industrial revolution. This study investigates changes in product lifecycle management in preparation for the 4th industrial revolution in the knowledge domain of the existing defined product life cycle management. In future research, it is necessary to redefine the knowledge domain of product life cycle management suitable for the era of the 4th industrial revolution and investigate the perception of experts. Considering the social culture and technological change factors of the 4th industrial revolution, the scope and scope of product life cycle management can be newly defined.

Development of a Solar Collector Performance of Cylindrical Parabolic Concentrating Solar Collector (태양열(太陽熱) 집열기개발(集熱器開發)에 관(關)한 연구(硏究) - 포물반사곡면(抛物反射曲面)으로된 2차원(二次元) 집광식(集光式) 태양열(太陽熱) 집열기(集熱器)의 성능분석(性能分析) -)

  • Song, Hyun Kap;Yon, Kwang Seok;Cho, Sung Chan
    • Journal of Biosystems Engineering
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    • v.10 no.1
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    • pp.54-68
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    • 1985
  • It is desirable to collect the solar thermal energy at relatively high temperature in order to minimize the size of thermal storage system and to enlarge the scope of solar thermal energy utilization. So far the concentrating solar collector has been developed to collect solar thermal energy at relatively high temperature, but it has some difficulties in maintaining the volumetric body of solar collector for long term utilization. On the other hand, the flat-plate solar collector has been developed to collect the solar thermal energy at low temperature, and it has advantages in maintaining the system for long term utilization, since it's thickness is thin and not volumetric. In this study, to develop a solar collector that has both advantages of collecting solar thermal energy at high temperature and fixing conveniently the collector system for long term period, a cylindrical parabolic concentrating solar collector was designed, which has two rows of parabolic reflectors and thin thickness such as the flat-plate solar collector, maintaining the optical form of concentrating solar collector. The characteristics of the concentrating parabolic solar collector newly designed was analysed and the results are summarized as follows; 1. The temperature of the air enclosed in solar collector was all the same as $50^{\circ}C$ in both cases of the open and closed loop, and when the heat transfer fluid was not circulated in tubular absorber, the maximum surface temperature of the absorber was $118-120^{\circ}C$, this results suggested that the heat transfer fluid could be heated up to $118^{\circ}C$. 2. In case of longitudinal installation of the solar collector, the temperature difference of heat transfer fluid between inlet and outlet was $4^{\circ}-6^{\circ}C$ at the flow rate of $110-130{\ell}/hr$, and the collected solar energy per unit area of collector was $300-465W/m^2$. 3. The collected solar energy per unit area for 7 hours was 1960 Kcal/$m^2$ for the open loop and 220 Kcal/$m^2$ for the closed loop. Therefore it is necessary to combine the open and closed loop of solar collectors to improve the thermal efficiency of solar collector. 4. The thermal efficiency of the solar collector (C.P.C.S.C.) was proportional to the density of solar radiation, indicating the maximum thermal efficiency ${\eta}_{max}=58%$ with longitudinal installation and ${\eta}_{max}=45%$ with lateral installation. 5. The thermal efficiency of the solar collector (C.P.C.S.C.) was increased in accordance with the increase of flow rate of heat transfer fluid, presenting the flow rate of $110{\ell}/hr$ was the value of turning point of the increasing rate of the collector efficiency, therefore the flow rate of $110{\ell}/hr$ was considered as optimum value for the test of the solar collector (C.P.C.S.C.) performance when the heat transfer fluid is a liquid. 6. In both cases of longitudinal and lateral installation of the solar collector (C.P.C.S.C.), the thermal efficiency was decreased linearly with an increase in the value of the term ($T_m-T_a$)/Ic and the increasing rate of the thermal efficiency was not effected by the installation method of solar collector.

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A Study on the Economical Nutrition Supplement of Cereal Food for Improvement in our National Eating Habits (국민식생활(國民食生活) 향상(向上)을 위(爲)한 곡류제품(穀類製品)의 경제적( 經濟的) 영향강화(營養强化)에 관(關)한 연구(硏究))

  • Ju, Jin-Soon;Yu, Jong-Yull;Kim, Sook-He;Lee, Ki-Yull;Han, In-Kyu
    • Journal of Nutrition and Health
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    • v.6 no.1
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    • pp.1-9
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    • 1973
  • I. Subject of the Study: Studies on the economical nutrition supplement of cereal foods for the improvement in our notional eating habits. II. Purpose and Importance of the Study: 1. Our nation is confronted with the situation that the rice, a principal food, short of some essential amino acids, lysine and threonine, leads to imbalanced meals insufficient in the nutrient of protein, to bring many difficulties in the elevation of our national physique. 2. The shortage of even the rice imperfect in the nutrient of protein makes the import of lots of foreign rice inevitable. It is considered that the protein supplement and decrease in the consumption amount, of rice, is a serious key to the solution of our food difficulty, and then a way of the proetin supplement of rice through the addition of essential amino acid is to be rarely applied in the view of the our present finance and situation. 3. In the present experiment, therefore, it aims to the suggestion of an aspect of the improvement in our national eating habits guiding in the nutrition elevation which our nation can afford economically through the development of first, a way of the protein supplement by the mixture of cereals producted plentifully in our country, and second, a way of the decrease in the consumption amount and the improvement in the nutrition of rice through the substitution of the other cereals for rice. III. Contents of Scope of the Study: 1. Objects of the study: Objects of the study are the following three items; a) The nutrition supplement of rice through the mixture of cereals. Our nation makes mainly rice as a principal food, but practically many kinds of cereal are produced in our country. They contain different levels and qualities of each nutrient and they are different from one another in the kinds of essential amino acid consisting protein. For that reason, the mutual complement efficeincy of insufficient nutrients is observed through the mixture of cereals. b) The nutrition supplement of rice through the addition of superior protein sources to rice, a principal food. The development of rice as superior foods in the sense of nutrition is conducted through the risement in protein quality by the addition of protein sources in good quality, for example, fish flour (anchovy flour), egg powder, milk powder, and so on, and through the supplement of vitamins and minerals. c) The decrease in the consumption amount of rice through the substitution of the other cereals for rice, as a principal food. The compensation for the short amount of rice is made by the reduction in the consumption of rice through the discovery of a way of substitution of the other cereals for rice, as a principal food and of the settlement of problems in nutrition and finance subsequent to this. 2. Contents of the study: a) An ideal mixture-ratio of cereals is established for rats by feeding mixed foods(rice-barely or rice-wheat) containing 5%, 15%, 25%, 35% and 45% level of either barely or wheat. b) The nutritive value is determined in the whole subsititution of other foods for rice, and then, a way of the complement of over and under nutrients is devised. c) The ideal combination is investigated for rats through feeding mixed foods of main food, rice and supplement foods of protein sources, soy bean, fish flour, egg powder and milk Powder. d) According to results from the above three experiments, the concise functional test for men and the examination of economical property are made. 3. Scope of the study: a) The observation of the effect of each diet on the growth rate for rats. The growth rate of rats was observed for 15 groups of mixed foods of a main food, rice, and wheat flour, barley powder or soy bean powder, respectively, and 12 groups of wheat flour diets supplemented with $1{\sim}3%$ milk powder, and rice or wheat flour diets supplemented with 5% of milk powder, egg powder, fish flour or soy bean powder, respectively. b) The determination of food consumption. The food consumption was determined at weekly intervals for 27 kinds of diet described in a) item. c) The determination of food efficiency rate. The food efficiency rate for each diet was determined by calculation from the gained body weight and the food consumption amount at the same intervals described in b) item. d) The determination of protein efficiency rate. The protein efficiency rate for each diet was determined by calculation form gained body weight and the protein amount of the food consumption amount at the same intervals described c) item. e) The determination of the body component. The hematocrite and hemoglobin levels in the blood, total nitrogen in the serum, blood sugar, and lipids and glycogen in the liver were determined. f) The observation of nitrogen balance. As a means of the observation of nitrogen balance, the total nitrogen in the urine was determined. g) The analysis of economical property. The economical property was analyzed as the gained body weight to the amount equivalent to one won through the conversion of the food consumption amount into money. h) The functional test for men. The concise functional test for men was made in order to establish if the best diet for experimental animals can be applied to men. IV. Results of the Study: The national food product plan, nationwide nutritive enlightment and the improvement activities in our country eating habits, especially, mixed and powder food problems are to be significantly referred, and the following results must be applied. a) In the mixed foods of cereals, the mixed food of the rice-barley containing $5{\sim}15%$ level of barley is best in terms of nutrition. b) The addition of superior protein sources, egg, Bilk, soy bean, or fish, respectively to either rice or wheat flour makes a great risement in the nutritive value. c) The animal protein is more effective in the elevation of nutritive value of cereals. d) Rice takes the most nutritive operation and has the highest preference, among rice, wheat flour and barley. e) Wheat flour is more economical than rice in evaluation of the gained body weight to the regular money, and the addition of fish or soy bean is more economical than that of any other supplement food. But the above results are true of the range of nutrition and economical property. f) The study on the nutrition composition and barley will lead to the improvement in our national eating habits as mixed food of the rice-barley containing $5{\sim}15%$ level of barley is more nutritive. g) This study on the nutrition only for the growing animal can not be considered as a perfect and entire evaluation. Consequently, the perfect data for our national nutrition can be obtained from the experiment similar to this for the much longer period examining, in details, the growth rate, change of physical strength, mental and bodily change, average life span, and resistance ability to infectious diseases.

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