• Title/Summary/Keyword: Scale Efficiency Change

Search Result 256, Processing Time 0.036 seconds

A Study on the Revitalization of Distribution and Logistics in the Least Developed Free Economic Zones (FEZ) (후발 경제자유구역의 성공을 위한 물류유통 부문 활성화에 관한 연구)

  • Jeon, Jae-Woan;Kim, Ki-Soo
    • Journal of Distribution Science
    • /
    • v.11 no.2
    • /
    • pp.57-70
    • /
    • 2013
  • Purpose - The objective of this paper is to explain the successful methods for the revitalization of distribution and logistics of the least developed FEZs (Saemangum, Yellow-sea, and Deagu-Kyengbuk) in Korea. With the recent changes in the economic terrain of Northeast Asia as with the rise of China, Korea has developed a logistics hub concept for improving the efficiency of logistics and distribution industry and its distribution and logistics policy has received positive worldwide evaluation. Therefore, we face severe competition and must always look for ways to address these problems. Research design, Data, Methodology - This study adopts two methods to propose successful revitalization of distribution and logistics in the least developed FEZ. The first method investigates the limitation of these FEZs by analyzing the statutes, and the second one follows comparable cases. Thus, we first reviewed the efficient strategic political alternatives for the least developed FEZ, Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk, through the relative institution system, law, and future plans. Next, we studied the Bin-hai Economic Free Section (Zone) in China as a comparable example. In order to analyze the competitiveness of logistics in the three FEZs (Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk), the total factor productivity growth of regional manufacturing industries is divided into three sources: the external trade effect, scale effect, and technical change effect. However, this paper does not test for a positive contribution of external trade, which is a reason of non-building on these FEZs. A FEZ that shows a larger external trade effect than the others will have a comparative advantage in the logistics infrastructure and policy support. This study presented the newly applied Bin-hai FEZ in China, in order to make the studied FEZ as successful by applying the strategy of its distribution and logistics center. Results - In Korea, there is an increased focus on the benefit of the regional development of regions such as the Free Economic Zones (FEZ). We have six FEZs, Inchon, Busan-Jinhae, Guangyang, Yellow-sea, Seamangum-Gunsan, and Deagu-Kyeongbuk. However, our FEZs do not have various supporting factors needed for the logistics and distribution industry. Korea designated the above six places as FEZ and has operated to enhance national competitiveness and ensure a balanced regional development since 2003. However, most FEZs did not receive favorable feedback in the first business performance evaluation and it is necessary to take action for substantial improvements. Conclusions - Especially, over the past 10 years, even though the FEZ policy has been implemented in an effort to promote success in distribution and logistics, there are still many underdeveloped industries in logistics. The main problem is the absence of revitalization of the high value added performance in the distribution and logistics industry. However, there is a limitation to this study. We have used non-empirical method based on a case study to arrive at our findings. Future studies should use appropriate statistical methods to supplement our results and provide a solution to this problem.

  • PDF

Oxygen Transfer and Hydraulic Characteristics in Bubble Column Bioreactor Applied Fine Bubble Air Diffusing System (미세기포 산기장치를 적용한 타워형 생물반응기의 산소전달 및 수력학적 특성)

  • Lee, Seung-Jin;Ko, Kyeong-Han;Ko, Myeong-Han;Yang, Jae-Kyeong;Kim, Yong-Guk
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.34 no.11
    • /
    • pp.772-779
    • /
    • 2012
  • For improving performance of conical air diffuser generating fine bubble, both experimental and numerical simulation method were used. After adapting diffusers inner real scale bubble column, suitable for various diffuser submergence, the effect of diffuser submergence on oxygen transfer performance such as Oxygen Transfer Coefficient ($K_{L}a_{20}$) and Standard Oxygen Transfer Efficiency (SOTE) was investigated empirically. As flow patterns for various diffuser number and submergence were revealed throughout hydrodynamic simulation for 2-phase fluid flow of air-water, the cause of the change for oxygen transfer performance was cleared up. As results of experimental performance, $K_{L}a_{20}$ was increased slightly by 7% and SOTE was increased drastically by 39~72%, 5.6% per meter. As results of numerical analysis, air volume fraction, air and water velocity in bioreactor were increased with analogous flow tendency by increasing diffuser number. As diffuser submergence increased, air volume fraction, air and water velocity were decreased slightly. Because circulative co-flow is determinant factor for bubble diffusion and rising velocity, excessive circulation intensity can result to worsen oxygen transfer by shortening bubble retention time and amount.

Electricity Generation and Microbial Community variation in Microbial Fuel Cell with various Electrode Combinations. (다양한 탄소전극조합에 따른 미생물 연료전지의 전기발생량 및 미생물 군집변화)

  • Kwon, Jae-Hyeong;Choi, Soo-Jung;Cha, Jae-Hwan;Kim, Hyo-Soo;Kim, Ye-Jin;Yu, Jae-Cheul;Kim, Chan-Won
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.32 no.1
    • /
    • pp.87-96
    • /
    • 2010
  • The electrode material is one of the factors affecting the power production of microbial fuel cell. In this study, effects of carbon electrode material, thickness and configuration on the power density, biofilm formation and microbial community diversity of microbial fuel cell were investigated. To optimize the anode-cathode electrode assembly, seven lab-scale reactors which had various carbon electrode constructions were operated in continuous mode. Under the steady state condition, the electrode combination of graphite felt (6 mm) with hole showed the highest cell voltage of 238 mV and the coulombic efficiency of 37%. As a result of SEM analysis, the bacteria growing on surface of knitted type of carbon cloth and graphite felt electrode ncreased significantly. The change of dominant species between seeding sludge and biofilm on the surface of anode electrode, microbial analysis with PCR-DGGE showed that the dominant species of seeding sludge are quite different from those of biofilm on the surface of each anode electrode. Especially Geobacter sp., a well known electrochemical bacteria, was found as the dominant species of the electrode combination with graphite felt.

The Effect of Soil Characters on Removal of Odorous Gases during Carcasses Degradation with Efficient Microorganisms (토질 특성에 따른 가축사체 매몰지의 악취 저감 연구)

  • Kim, Hyun-Sook;Park, Sujung;Jung, Weon Hwa;Srinivasan, Sathiyaraj;Lee, Sang-Seob
    • Journal of Korean Society of Environmental Engineers
    • /
    • v.36 no.4
    • /
    • pp.277-285
    • /
    • 2014
  • The usage of efficient microorganism (EM) is increasing in concern for server purposes including odor removal during carcasses degradation. In this study, we have studied the type of soil and its effect on efficient microorganisms for the removal of odorous gases during buried carcasses degradation in lab-scale reactor. The carcasses are buried in the reactor with various soil types such as normal soil, 20% sandy and 20% clay soil with the efficient microorganism KEM. The efficient microorganisms KEM have the ability to stabilize the degradation of carcasses of the burial site. We have focused on the analysis of odorous gases such tri-methylamine (TMA), hydrogen sulfide ($H_2S$), methyl mercaptan (MM), dimethyl sulfide (DMS), dimethyl disulfide (DMDS), carbon dioxide ($CO_2$), and methane ($CH_4$) along with the changes of microbial community changed during complete degradation of buried carcasses for a year. The results suggested that the 20% sandy soil contain lesser level of $H_2S$ and MM (0.09 and 0.35 mg) but 20% clay has higher nitrogen compound removing effect and leave only less amount of ammonia and TMA (0.31 and 2.06 mg). The 20% sandy soil also has the ability to breakdown the carcasses more quality compared with other types of soil. Based on the data obtained in this study suggesting that, the use of 20% sandy soil can effectively control sulfur compounds whereas 20% clay soil controls nitrogen compounds in the buried soil. Depending on the type of the soil, the dominant of microbial communities and the distribution was change.

Data-driven event detection method for efficient management and recovery of water distribution system man-made disasters (상수도관망 재난관리 및 복구를 위한 데이터기반 이상탐지 방법론 개발)

  • Jung, Donghwi;Ahn, Jaehyun
    • Journal of Korea Water Resources Association
    • /
    • v.51 no.8
    • /
    • pp.703-711
    • /
    • 2018
  • Water distribution system (WDS) pipe bursts are caused from excessive pressure, pipe aging, and ground shift from temperature change and earthquake. Prompt detection of and response to the failure event help prevent large-scale service interruption and catastrophic sinkhole generation. To that end, this study proposes a improved Western Electric Company (WECO) method to improve the detection effectiveness and efficiency of the original WECO method. The original WECO method is an univariate Statistical Process Control (SPC) technique used for identifying any non-random patterns in system output data. The improved WECO method multiples a threshold modifier (w) to each threshold of WECO sub-rules in order to control the sensitivity of anomaly detection in a water distribution network of interest. The Austin network was used to demonstrated the proposed method in which normal random and abnormal pipe flow data were generated. The best w value was identified from a sensitivity analysis, and the impact of measurement frequency (dt = 5, 10, 15 min etc.) was also investigated. The proposed method was compared to the original WECO method with respect to detection probability, false alarm rate, and averaged detection time. Finally, this study provides a set of guidelines on the use of the WECO method for real-life WDS pipe burst detection.

The Problems in the Medical Dispute Mediation Process According to the "Act on Remedies for Injuries from Medical Malpractice and Mediation of Medical Disputes" and the Alternative Propsal (의료분쟁조정제도 운영에 따른 문제점 및 개선 방안)

  • Hwang, SeungYun
    • The Korean Society of Law and Medicine
    • /
    • v.14 no.1
    • /
    • pp.85-116
    • /
    • 2013
  • Korea Medical Dispute Mediation and Arbitration Agency, "K-MEDI" in abbr. herein-after, is established on Apr. 9, 2012 according to the law cited in the title above for the purpose of settling medical disputes in a prompt, fair and efficient manner. Two special professional organizations are established in K-MEDI, one of them is Medical Dispute Mediation and Arbitration Committee(hereinafter referred to as the "Mediation Committee") and the other Medical Malpractice Appraisal Board(hereinaf-ter referred to as the "Appraisal Board"), the mission of the latter is to investigate the facts concerning the disputed medical conduct and to research as to and apprai-se whether the medical conduct was negligent and whether a causal relationship exists. Each panel organized in the Mediation Committee or the Appraisal Board shall be comprised of five mediators or appraisers, including necessarily a judge or a prose-cutor respectively and any disputed case regardless of the scale, the importance or the complicacy shall be handled by a panel. As the system is not thought efficient or economic, the number of the members comprising a panel or total members com-prising the Mediation Committee or the Appraisal Board shoud be adjusted, and the process shoud be versified, including the "Rapid Process," for instance. A petition for the mediation of a medical dispute shall be rejected if the respondent fails to notify K-MEDI of his/her intention to accede to the mediation within 14days from the day on which the petition for the mediation was served(Art. 27 Cl. 7). As the option of an arbitrary decision whether the mediation proceedings shall be commenced or not given to the respondent by the clause is thought unfair, making the process unstable, and moreover, diminishing the purpose of the system established by the law cited above for solving the medical disputes, the clause shoud be amended not to allow the respondent the option of such an arbitrary deci-sion. K-MEDI shall conduct the "Program for Compensation of Medical Accidents"(Art 46) according to which unavoidable injuries caused by the medical accidents in the cour-se of childbirth and the "Advances for Damages"(Art. 47) that are the compensating moneys paid to victims in medical malpractice cases who fail to receive money at all or partly from the operator or the professional of a public health or medical institution although he/she has a final and conclusive right to be paid by them. Some operators or professionals of such institutions claim that both the programs violate their fundamental rights assured by the constitution, and that it be a justifica-tion of refusal to accede to the mediation. As any of the programs needs not to be conducted by K-MEDI, it may be a proper solution to change the conductor of the programs to avoid the unproductive controversy.

  • PDF

Deflection Evaluation of the Constructing-load Carrying Capacity for Deep Decking Floor System Reinforced with Both Ends Cap Plates (캡 플레이트로 단부 보강한 춤이 깊은 데크의 시공중 처짐성능평가)

  • Jeon, Sang Hyun;Kyung, Jae Hwan;Kim, Young Ho;Choi, Sung Mo;Yang, Il Seung
    • Journal of Korean Society of Steel Construction
    • /
    • v.27 no.2
    • /
    • pp.155-167
    • /
    • 2015
  • If of application of the deep deckting floor in long span more than 6m, the deflection caused by the construction load occurred high. Because the constructing-works and safety by this deflection, take actually supports to laborers working on the deck. However, installed supports are having difficultly such as the restricted passage, deficiency of working space, and lowering of efficiency. And toward-opening deck is seen as local buckling of web plate, flexural-torsional buckling, and gradually opening of corrugated decking. In this study, we will suggest a deep decking floor system that reinforced with both ends cap plates for toward-opneing decking change from opening to closing. The constructing deflection of a deep decking more than 6m must be satified 30mm and L/180 as proposed. Full-scale field tests loading by sand conducted a deep decking reinforced with and without cap plate. In conclusion, the specimen reinforced with cap plates have shown that to ensure the negative moment $wl^2/18$. And constructing-deflection of deep decking shown that to satisfy the evaluation value (L/180 or 30mm).

A study on estimation status and improvement plan of the repair and replacement cycle of a building (건축물 수선교체주기 산정현황과 개선방안에 관한 연구)

  • Kim, Jong-Rok;Son, Jae-Ho
    • Journal of the Korea Institute of Building Construction
    • /
    • v.10 no.1
    • /
    • pp.193-198
    • /
    • 2010
  • This study aimed at presenting the improvement plan for estimation of the repair and replacement cycle to analyze these current problems by considering the repair and replacement cycle theoretically and examining estimation status of home and abroad, and then drawing implication and problem based on brainstorming and expert opinion. The findings of a study is as follows. First, the problem is, for the domestic, that there is no clear standard of division to the cycle of repair and replacement and the repair and replacement cycle considering capability to deal with the change by construction method, development of the function of material and the number of years of progress is not being applied. That is, an estimation of economical repair and replacement cycle which considers the case that a large scale repair with the level of remodeling is done between 25 years and 35 years is necessary. For estimating the repair and replacement cycle, foreign country is providing this according to the use or the level of function of a building, but it is not the case for the domestic. A characteristic of each building should be reflected and the standard of estimation of the repair and replacement cycle to new construction material or method should be prepared to improve this. In addition, the method of classification of the subject item for the repair and replacement is necessary to be reorganized to be able to apply the standard of initial construction item of a building. Also, it is considered that a service standard which can reset the repair and replacement cycle based on status of a building with escape from the existing definite setup of the repair and replacement cycle through the management of background data of the repair and replacement is going to be necessary.

The Post-IMF firm strategy and the corporate restructuring in the heavy & chemical industrial district: the case of Ulsan, Korea (울산 중화학공업의 재구조화 특성 - IMF 체제 이후의 기업전략을 중심으로 -)

  • Park, Yang-Choon
    • Journal of the Korean association of regional geographers
    • /
    • v.7 no.2
    • /
    • pp.17-34
    • /
    • 2001
  • This paper is to analyze how firms in a large firm-led industrial city have carried out the restructuring in the face of radical shifts, with focus on the strategy and the restructuring of firms in Ulsan, a typical industrial district in Korea that is specialized in heavy & chemical industry. It has been well known that the local economy has been led by a small number of large firms, including affiliates of chaebol, and its industrial structure has also been characterised as a clear dichotomy between large firms as a customer and small and medium-size firms as a supplier, which can be called not horizontal but vertical relations. It can identify some tendencies, however, that local companies have been rather dynamically changing in response to increasingly turbulent environment since the Asian crisis. Some are radical, but some incremental. These can be summarized in four distinctive but interlinked ways. First, more than half of local companies surveyed have attempted to change their production systems, mainly from the fordist mass production towards the flexible mass production, seeking both economies of scale and scope. Second, local firms have vigorously continued to reorganize the boundary of the production and the organization, by specializing products and focusing on the core competence in order to save costs and cope with radically changing customer demands in a flexible way. Third, there have been various strategies for the organizational innovation such as the introduction of team organization, the boundary blurring between the managerial and production workers and the intra-firm spin-offs, so as to improve managerial efficiency and competence in the use of internal labour market. Finally, they have tried to be more sensitive to the market and customers. These tendencies seem to be increasingly critical to sustain their competitiveness. To do so, they tend to focus increasingly not only on the competing via the product quality rather than through price, but also to seek to diversify the market and customer firms beyond national boundary.

  • PDF

High Energy Density Germanium Anodes for Next Generation Lithium Ion Batteries (다음세대 리튬이온 배터리용 고에너지 밀도 게르마늄 음극)

  • Ocon, Joey D.;Lee, Jae Kwang;Lee, Jaeyoung
    • Applied Chemistry for Engineering
    • /
    • v.25 no.1
    • /
    • pp.1-13
    • /
    • 2014
  • Lithium ion batteries (LIBs) are the state-of-the-art technology among electrochemical energy storage and conversion cells, and are still considered the most attractive class of battery in the future due to their high specific energy density, high efficiency, and long cycle life. Rapid development of power-hungry commercial electronics and large-scale energy storage applications (e.g. off-peak electrical energy storage), however, requires novel anode materials that have higher energy densities to replace conventional graphite electrodes. Germanium (Ge) and silicon (Si) are thought to be ideal prospect candidates for next generation LIB anodes due to their extremely high theoretical energy capacities. For instance, Ge offers relatively lower volume change during cycling, better Li insertion/extraction kinetics, and higher electronic conductivity than Si. In this focused review, we briefly describe the basic concepts of LIBs and then look at the characteristics of ideal anode materials that can provide greatly improved electrochemical performance, including high capacity, better cycling behavior, and rate capability. We then discuss how, in the future, Ge anode materials (Ge and Ge oxides, Ge-carbon composites, and other Ge-based composites) could increase the capacity of today's Li batteries. In recent years, considerable efforts have been made to fulfill the requirements of excellent anode materials, especially using these materials at the nanoscale. This article shall serve as a handy reference, as well as starting point, for future research related to high capacity LIB anodes, especially based on semiconductor Ge and Si.