• Title/Summary/Keyword: 김동환

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Improvement Strategies of Agro-Value Chain for Agricultural Development in Developing Countries: The Case of Cambodia (개도국 농업발전을 위한 농산물 가치사슬 개선 전략: 캄보디아 사례를 중심으로)

  • Kim, Dong-Hwan
    • Journal of Distribution Science
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    • v.14 no.4
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    • pp.127-134
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    • 2016
  • Purpose - Value chain in agriculture refers to direct and indirect activities related to value-added process from raw materials to final products in agricultural industries. In recent years, value chain analysis has become more important in the area of agricultural development. This article reviews the concept and importance of value chain analysis in the context of agricultural development and attempts to suggest improvement strategies. Research design, data, methodology - A literature survey was conducted for value chain analysis for agricultural development. The case of agro-value chain in Cambodia was deeply analyzed based upon interviews with government officers and related experts. Results - It seems that agro-value chain in developing countries are not well developed and does not carry out appropriate functions, compared to developed countries. Because value adding facilities, such as storage, processing and packing plants, milling plants, and etc. are not sufficiently constructed, the quality of agricultural products is low. Especially developing countries may loose opportunities to increase value of their product by exporting their agricultural products as raw materials to neighboring countries. Value adding process is also mainly controlled by traders in local markets or wholesale markets in urban areas. Farmers therefore can get lower share of final value of agricultural products compared to the shares paid to traders. Lastly it is argued that governments of developing countries do not play an active role in developing value chains and do not carry out coordinating functions in an effective and efficient manner. Conclusions - The first step to improve agro-value chain in developing countries is to identify and analyze value chain structure of agricultural products and to make development strategies and implementation programs. For improving value chain of agricultural products in developing countries, it is required to provide not only plans for constructing hardwares, such as wholesale markets, storage facilities, processing and packing plants, and etc., but also plans for improving softwares, such as measures for improving product quality and safety, setting up grade and standard, providing market information, and nurturing producer cooperatives.

CFD Analysis on the Flow Characteristics of Diffuser/Nozzles for Micro-pumps (마이크로 펌프용 디퓨져/노즐의 유동 특성에 관한 CFD 해석)

  • Kim Donghwan;Han Dong-Seok;Jeong Siyoung;Hur Nahmkeon;Yoon Seok-Jin
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.6
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    • pp.544-551
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    • 2005
  • The flow characteristics have been numerically investigated for various shapes of the diffuser/nozzles which are used for a valveless micro-pump. The important parameters considered in this study are the throat width ($15\~120\mu$m), the taper angle ($3.15\~25.2^{\circ}$), and the diffuser length ( $600\~4,800\mu$m), and the size of the middle chamber ($1\~16mm^2$). To find the optimal values for these parameters, steady state calculations have been performed assuming the constant pressure difference between the inlet and exit of the flow For the taper angle and the throat width, it is found that there exists an optimum at which the net flow rate is the greatest. The optimal taper angle is in the range of $10\~20^{\circ}$ for all the pressure differences; and the throat width indicates an optimal value near $75\mu$m for the case of 35 kPa pressure difference. The net flow rate is also influenced by the size of the middle chamber. With decreasing chamber size, the net flow rate is reduced because of the interference between two streams flowing into the middle chamber. The unsteady pulsating flow characteristics for a micro-pump with a given diffuser/nozzle shape have been also investigated to show the validity of the steady state parametric study.

Nitrogenation Process and Magnetic Properties of $Sm_{2}Fe_{17}$-Nitride ($Sm_{2}Fe_{17}N_{x}$의 질화과정 및 자기특성)

  • 김동환;권혁무;김택기;김희태;김윤배
    • Journal of the Korean Magnetics Society
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    • v.5 no.5
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    • pp.858-863
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    • 1995
  • The nitrogenation process and magnetic properties of $Sm_{2}Fe_{17}N_{x}\;(0{\leq}x{\leq}3)$ were investigated. During the initial nitrogenation process, the nitrogen content had linear relation with the square root of nitrogenation time, and the activation energy for the process was calculated to be 102.4 kJ/mol. The magnetic properties of $Sm_{2}Fe_{17}N_{x}$ were strongly dependent on the nitrogen content and the composition having $Sm_{2}Fe_{17}N_{2.8}$ showed optimum magnetic properties with a Curie temperature of 450 oC. The intrinsic magnetic properties of the nitride at room temperature were $M_{s}=1147\;emu/cm^{3},\;K_{1}=4.6{\times}10^{7}erg/cm^{3},\;K_{2}=6.0{\times}10^{7}erg/cm^{3}\;and\;H_{A}=290\;kOe$, respectively.

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A Case Study on Effect of Herbal Diet an Male Abdominal Obese Patient (남성 복부비만 환자의 치험 1례)

  • Kim, Kil-Soo;Kim, Dong-Yeol;Kim, Dong-Hwan
    • Journal of Korean Medicine for Obesity Research
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    • v.2 no.1
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    • pp.89-94
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    • 2002
  • We experienced a male patient who was diagnosed as very severe abdominal obesity. From the 3rd of January to the 14th of April we applied herbal medication(Tiganyiyiren-tang), very low calorie diet, aerobic exercise, behavioral therapy, electrolipolysis, infra-red therapy, auricular acupuncture, and aqua-massage to him. And we examined the changes of his height, weight, body composition, body size, liver functional test, abdominal CT finding. The food production of this year has decreased by 5 percent. His weight decreased by 28.2%, PIBW by 28.5%, BMI by 28.2%, PBF by 22.7%, and WHR by 15.9%. The circumference of upper extremity decreased by 25.7%, the circumference of the muscle of upper extremity by 18.2%, the circumference of chest by 20.5%, the circumference of abdomen by 29.5%, the circumference of hip by 17.4%, and the circumference of thigh by 15.9%. In the liver functional test GOT decreased from 42IU/l to 361U/I, GPT from 1211U/l to 48IU/I. Total cholesterol from 211mg/dl to 152mg/dl, and Trigliceride from 192mg/dl to 81 mg/dl. In the abdominal CT finding the amount of fat in the abdominal cavity decreased from $9732mm^2$ to $3639mm^2$.

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Contact Microscopy by Using Soft X-ray Radiation from Iodine Laser Produced Plasma (옥소레이저 플라즈마에서 발생된 연 X-선을 이용한 밀착현미경기술)

  • 최병일;김동환;공홍진;이상수
    • Korean Journal of Optics and Photonics
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    • v.1 no.1
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    • pp.46-51
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    • 1990
  • Laser plasma was generated by a 1GW iodine photodissociation laser ($\lambda$=1.315$\mu\textrm{m}$, E=12.7J) whose output beam was focused on a molybdenum target surface. The experiment was conducted in a vacuum chamber under 1D-sTorr and several tens of laser shooting were necessary for sufficient exposure for the PBS resist of 111m thickness. Aluminium was coated on the top of the resist by 0.1$\mu\textrm{m}$ thickness which acts as an X-ray filter to cut off the visible and the ultraviolet lights. A bio-specimen was put directly on the aluminium coated resist and located at a distance of 3 cm from the X-ray source. The replicas of a steel mesh, spider's web. and a red blood cell were obtained by this technique and were observed by Nomarski microscope and SEM. The limitation of its resolution is determined by the X-ray source size and Fresnel diffraction effect, and its theoretical prediction is well matched with the experimental results. In this experiment, a resolution better than 0.1$\mu\textrm{m}$ could be obtained. ained.

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A Patient with Methemoglobinemia after Herbicide Intoxication has Hemolytic Anemia Induced by Methylene Blue (제초제 중독으로 유발된 메트헤모글로빈혈증 환자에서 메틸렌블루 사용 후 발생한 용혈성 빈혈 1례)

  • Kim, Sun-Pyo;Kim, Dong-Hwan;Sun, Kyung-Hoon;Yoon, Dae-Heung;Kim, Seong-Jung;Cho, Soo-Hyeong;Cho, Nam-Soo
    • Journal of The Korean Society of Clinical Toxicology
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    • v.6 no.2
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    • pp.134-137
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    • 2008
  • Methylene blue is the first choice for treating methemoglobinemia, any increase in normal methemoglobin levels. Methemoglobin is an abnormal hemoglobin in which the iron has been oxidized to the ferric(+3) state, making it incapable of oxygen transport. Methemoglobinemia most commonly results from exposure to oxidizing chemicals, but may also arise form genetic, dietary, or even idiopathic etiologies. Patients with low methemoglobin levels are asymptomatic, but high methemoglobin levels can lead to headaches or even death. Methylene blue, the first-line treatment for methemoglobinemia, can also produce hemolytic anemia. Jaundice or dark urine during methylene blue treatment may indicate hemolytic anemia. A 47-year-old female patient with a history of depressive mood disorder developed significant methemoglobinemia after ingesting a Propanil overdose. Twenty-two hours after ingestion, methemoglobin levels in the blood were 73.2%. She was treated with intravenous methylene blue in the therapeutic range (1 mg/kg every 4 h for 3days). The 2nd day after methylene blue use, methemoglobin levels in the blood were 33%, and the 5th day decreased to 10% with better general condition. The patient had hyperbilirubinemia after hemolytic anemia, but she recovered completely.

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A Study on the 1955 to 1962 China's Policies toward Africa Region -focusing on the Bandung Conference and the Afro-Asian People's Solidarity - (1955-1962 기간의 중국 대외정책에 관한 연구 - 반둥회의와 아시아-아프리카 인민연대회의를 중심으로 -)

  • Kim, Dong Hwan
    • International Area Studies Review
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    • v.13 no.3
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    • pp.873-896
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    • 2009
  • China's the resource diplomacy towards Africa as successful results that are difficult to find precedents even within the world's diplomatic community. These results was after having its first diplomatic contact with Africa, during the Bandung Conference of 1955, China supported the armed independence movement of each colony in Africa. These several material and immaterial ad and sacrifice continued for over half a century and they could be see as the products of the Cold War that was created. The importance of the argument, how did and international relation that began as an idea extend into the spheres of politics and economics, has resurfaced. With this objective, the purpose of this research is to understand the initial stages of Chinese versus African policies that started with the first official contact between China and Africa, centered on the 1995 Bandung Conference and the 1957 Afro-Asian People's Solidarity and Study the development of the ensuing relationship.

Localization and Subsidiary Performance of Korean Multinationals - Performance Factors by Sector and Country (한국 다국적기업 해외자회사의 현지화 수준과 경영성과 - 산업별·국가별 성과요인 비교 분석)

  • Hwang, Eunhye;Kim, Donghwan;Lee, Hongshik
    • International Area Studies Review
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    • v.20 no.3
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    • pp.81-100
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    • 2016
  • In this study we analyze the performance of overseas subsidiaries of Korean multinationals with localization in sales, purchase, and employment. We use the data of 2,116 overseas subsidiaries in 61 countries between 2008 and 2011 provided by The Export-Inport Bank of Korea. As a result, analysis shows that the effect of localization on the performance is quite different by sectors and countries which the subsidiaries have entered. In the manufacturing sector, increase of local sales has positive effect only in China, while local purchase improves the performance of the subsidiaries in developing counties excluding China. However, the subsidiaries which had made a foray to service sector in advanced countries aquired better performance with localization of sales, purchase, and employment, whereas those in China had no merit except localization of purchase.

Mechanism Design and Control Technique of Duct Cleaning Robot with Self-position Recognition (자기위치 인식 가능한 덕트 청소로봇의 메카니즘 설계 및 제어기법)

  • Jang, Woojin;Seo, Myungin;Ha, Junhwan;Park, Kyongtae;Kim, Dong-Hwan
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.1
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    • pp.85-95
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    • 2019
  • This work shows how to design a robot structure and to control to overcome obstacles while traveling through ducts of various diameters and shapes by three-legged robot. Circuits are centered in the body to connect the three wheel bodies that are driven around the center body with the 4-section slider link structure. Also, the springs are used to contract and expand the robot legs so that it can be caparable of various environments. Geared motor, spring, and belt were selected based on the static and dynamic calculation to be suitable to horizontal and vertical travels. The center body is equipped with a camera and the distance sensors, and a control algorithms are implemented so that it can be successfully performed in L-type and T-type ducts. Using UWB modules and trilateration algorithm, the location of the duct-cleaning robot inside the duct could be identified successfully.

Kernel Regression Model based Gas Turbine Rotor Vibration Signal Abnormal State Analysis (커널회귀 모델기반 가스터빈 축진동 신호이상 분석)

  • Kim, Yeonwhan;Kim, Donghwan;Park, SunHwi
    • KEPCO Journal on Electric Power and Energy
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    • v.4 no.2
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    • pp.101-105
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    • 2018
  • In this paper, the kernel regression model is applied for the case study of gas turbine abnormal state analysis. In addition to vibration analysis at the remote site, the kernel regression model technique can is useful for analyzing abnormal state of rotor vibration signals of gas turbine in power plant. In monitoring based on data-driven techniques correlated measurements, the fault free training data of shaft vibration obtained during normal operations of gas turbine are used to develop a empirical model based on auto-associative kernel regression. This data-driven model can be used to predict virtual measurements, which are compared with real-time data, generating residuals. Any faults in the system may cause statistically abnormal changes in these residuals and could be detected. As the result, the kernel regression model provides information that can distinguish anomalies such as sensor failure in a shaft vibration signal.