• Title/Summary/Keyword: Improvement strategy

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Design Analysis of Hydraulic Excavator since 1990 (1990년대 유압굴삭기 조형 분석에 관한 연구)

  • 윤진필;문무경
    • Archives of design research
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    • v.13 no.4
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    • pp.233-242
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    • 2000
  • The traditional image of hydraulic excavator started to change in two ways since 1990. First, post-heavy equipment's visual image was new waves to traditional image of heavy, strong, and wild. They are the negative aspect that excavators have. Another movement of getting rid of its negative image can be found in late-heavy equipment, which was intended to adapt traditional and positive, but off negative images. In 1990s, the design trend is moving from warm/hard to warm/soft, and KOBELCO can be exceptional example that went even further, gone up to cool-soft image. KOBELCO specially aimed 'post- excavator image' strategy, which has been successful. Image of cabin as a human space changed little bit further than outside image. Each company tried to differentiate the design of cabin focusing on its safety. Following paragraphs show specific trend of image change in form, colour, texture, and the composition. Major visual image change in form tries to follow the image of cars and home appliances which are showing the movement from tough and hard image to soft one. Structural change on local image shows the movement from angular edge to edgeless and the movement of cabin's pillar C placed to back of the equipment with gentle inclination. All of these movements are the result of effort to improve traditional excavator's negative image, that top structure is assembled separately, to positive ones. Today's tendency about its color becomes important to apply two different colour styles. Each style has brightness and tone comparison. As an enormous power convey system, it was in common that its brightness comparison was useful because of the alarm of its damage possibility. However, as its colour control and its design have been emphasized gradually, the tone comparison takes a part in an important role, too. As an example, there is an occasion that these comparisons are compromised simultaneously. In the respect of its image creation, its texture treatments make the tendency of being the same as passenger cars. It is caused from its development of the manufacture techniques of from the fabrication method in small business to the press method in big firm. Further, it is also because of its improvement of painting & coating skills. It may prohibit the reflection effect from solar rays. In the point of view of its visual images, it is recognized the prominent tendency that its composition has been gradually decreased. Lots of windows and the frames tends dark-colour as a whole. It is more preferred to have one colour image, but except KOBELCO and HITACHI. As well, there is another high-tendency to improve its standard treatments, especially for its corner and texture treatments.

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Review of the Current Forage Production, Supply, and Quality Measure Standard in South Korea

  • Kim, Jong Duk;Seo, Myeongchon;Lee, Sang Cheol;Han, Kun-Jun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.3
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    • pp.149-155
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    • 2020
  • Cattle feeding in South Korea has been heavily dependent on domestically produced rice straw and imported grain. Around 42% of domestically produced rice straw is utilized for forage, and the remainder is recycled to restore soil fertility. Approximately 35% of round baleages were made with rice straw. However, higher quality hay is desired over rice straw. Due to increasing stockpiles of rice, there has been an economic burden on the government to store the surplus; therefore production of annual forage crops in rice fields has been further promoted in recent years. Hay import from the USA currently constitutes more than 80% of total imported hays. The main imported hays are alfalfa (Medicago sativa), timothy (Phleum pretense), and tall fescue (Festica arundinacea). The estimated forage required for cattle feeding was approximately 5.4 million MT in 2016. Domestically produced forage sates only 43% of that value, while low quality rice straw and imported hay covered the rest of demand by 33% and 20%, respectively. As utilization of domestically produced forage is more desirable for forage-based cattle production, long-term strategies have been necessary to promote domestic production of high quality baleage. One such strategy has been utilizing the fertile soil and abundance of fallow rice fields of western region of S. Korea to produce forage crops. Italian ryegrass (Lolium multiflorum) is the most successfully produced winter annual in the region and is approximately 56% of the total winter annual forage production. Forage sorghums (Sorghum bicolor), sorghum × sudangrass hybrids, and hybrid corn (Zea mays) produce a substantial amount of warm-season forage during summer. Produced forage has been largely stored through baleage due to heavy dew and frequent rains and has been evaluated according to S. Korea's newly implemented baleage commodity evaluation system. The system weighs 50% of its total grading points on moisture content because of its importance in deliverable DM content and desirable baleage fermentation; this has proved to be an effective method. Although further improvement is required for the future of forage production in South Korea, the current government-led forage production in rice fields has been able to alleviate some of the country's shortage for quality hay.

Aerodynamic Design of EAV Propeller using a Multi-Level Design Optimization Framework (다단 최적 설계 프레임워크를 활용한 전기추진 항공기 프로펠러 공력 최적 설계)

  • Kwon, Hyung-Il;Yi, Seul-Gi;Choi, Seongim;Kim, Keunbae
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.3
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    • pp.173-184
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    • 2013
  • A multi-level design optimization framework for aerodynamic design of rotary wing such as propeller and helicopter rotor blades is presented in this study. Strategy of the proposed framework is to enhance aerodynamic performance by sequentially applying the planform and sectional design optimization. In the first level of a planform design, we used a genetic algorithm and blade element momentum theory (BEMT) based on two-dimensional aerodynamic database to find optimal planform variables. After an initial planform design, local flow conditions of blade sections are analyzed using high-fidelity CFD methods. During the next level, a sectional design optimization is conducted using two dimensional Navier-Stokes analysis and a gradient based optimization algorithm. When optimal airfoil shape is determined at the several spanwise locations, a planform design is performed again. Through this iterative design process, not only an optimal flow condition but also an optimal shape of an EAV propeller blade is obtained. To validate the optimized propeller-blade design, it is tested in wind-tunnel facility with different flow conditions. An efficiency, which is slightly less than the expected improvement of 7% predicted by our proposed design framework but is still satisfactory to enhance the aerodynamic performance of EAV system.

Exploring the Characteristics of Environmental Catalysts of the Disadvantaged Gifted in Music (사회적 배려대상 음악영재의 환경요인 특징 탐색)

  • Kim, Sunghye;Lee, Kyungjin
    • Journal of Gifted/Talented Education
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    • v.24 no.4
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    • pp.629-655
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    • 2014
  • This study aims to explore the characteristics of environmental catalysts which have affected the development of music giftedness of the disadvantaged students. For this purpose, this study deals with nineteen disadvantaged gifted in music and examines their self-evaluation test, personal statement, and interview. Based on Gagn$\acute{e}$'s environmental catalysts of differentiated model of giftedness and talent(DMGT), the analysis of the interviews conveys the milieu of the disadvantaged gifted hardly exerts positive influences on their musical activities and studies. While concerning music and supporting their children financially and emotionally, parents unintentionally tend to exert negative influences on their children for their misapprehension of giftedness and incompetent advice. On the whole, the disadvantaged gifted hardly admit their teachers as experts in music. In relation to provisions, most students participate in extra school and local program and none of them participates in music gifted program. They are not satisfied with the quality in education. Despite the importance of the events such as crystallizing experience, award-winning, and performance, most students don't have enough events for inspiring their giftedness. As a conclusion, this study gives a proposition for a strategy to improve the environmental catalysts for the disadvantaged gifted in many different ways: the improvement of social recognition, the enhancement of parent consulting and teachers training programs, and the development and diffusions of more qualified gifted programs and so on.

Efficacy and Tolerability of Moclobemide Compared with Amitriptyline in Dysthymic Disorder (기분부전장애에서 Moclobemide와 Amitriptyline의 치료 효과와 내약성 비교 연구)

  • Lee, Min Soo;Nam, Jong Won;Ryu, Seung Ho;Cha, Ji Hyun;Kim, Yong Ku
    • Korean Journal of Biological Psychiatry
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    • v.6 no.1
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    • pp.96-101
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    • 1999
  • Background : Since dysthymia begins in late childhood or adolescence and has a chronic course, long-term pharmacotherapy may be required. New generation antidepressant, moclobemide, with more acceptable side effect profiles, is effective in the treatment of dysthymia. The main objective of this study was to determine whether they exhibit comparable efficacy and tolerability in dysthymia to amitriptyline. Method and Materials : The efficacy and tolerability of the moclobemide and amitriptyline, were compared in a eight-week single-centre double-blind study in patients(n=37) with dysthymia using he HAMD-17, the Clinical Global Impression Scale(CGI), the Montgomery-Asberg Depression Rating Scale (MADRS), Efficacy Index-Therapeutic Index(EITE), 4-point Index Side Effect Scale(4-PISES), and Efficacy Index- Side Effect Scale(EISE). Results : A total of 37 patients entered the study, 19 were randomly assigned to the moclobemide group and 18 to be amitriptyline group. Demo-graphic and illness characteristics were similar in both groups. There were no significant difference between two groups at the total 17-HDRS score, the HAMD-17% improvement, the total MADRS score, CGI response, and the EITE. In the comparison of EISE between two groups, the scores of the moclobemide group were relatively lower than the amitriptylinen group in full treatment. And the differences were significant(moclobemide group $1.39{\pm}0.61$ ; amitriptyline group $2.00{\pm}0.85$, p<.001). At the 4-PISE, There was no serious or treatment threatening side effects. And there was no specific difference in side effects between two groups. The moclobemide group reported higher EIR scores than the amitriptyline group at every follow up day, but the differences were not significant. And, there was no significant differences in the scores of five HRQOL subcategories which is compared between two groups at every follow up days. Conclusions : In terms of 17-HDRS and MADRS, moclobemide and amitriptyline are equally effective at least in allevating dysthymic symptoms. But moclobemide tended to be less troubling and better tolerated than amitriptyline. Therefore, moclobemide treatment can be used as a safe, and higher satisfactory treatment strategy for the dysthymia.

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Enhanced Efficacy of Human Brain-Derived Neural Stem Cells by Transplantation of Cell Aggregates in a Rat Model of Parkinson's Disease

  • Shin, Eun Sil;Hwang, Onyou;Hwang, Yu-Shik;Suh, Jun-Kyo Francis;Chun, Young Il;Jeon, Sang Ryong
    • Journal of Korean Neurosurgical Society
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    • v.56 no.5
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    • pp.383-389
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    • 2014
  • Objective : Neural tissue transplantation has been a promising strategy for the treatment of Parkinson's disease (PD). However, transplantation has the disadvantages of low-cell survival and/or development of dyskinesia. Transplantation of cell aggregates has the potential to overcome these problems, because the cells can extend their axons into the host brain and establish synaptic connections with host neurons. In this present study, aggregates of human brain-derived neural stem cells (HB-NSC) were transplanted into a PD animal model and compared to previous report on transplantation of single-cell suspensions. Methods : Rats received an injection of 6-OHDA into the right medial forebrain bundle to generate the PD model and followed by injections of PBS only, or HB-NSC aggregates in PBS into the ipsilateral striatum. Behavioral tests, multitracer (2-deoxy-2-[$^{18}F$]-fluoro-D-glucose ([$^{18}F$]-FDG) and [$^{18}F$]-N-(3-fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl)nortropane ([$^{18}F$]-FP-CIT) microPET scans, as well as immunohistochemical (IHC) and immunofluorescent (IF) staining were conducted to evaluate the results. Results : The stepping test showed significant improvement of contralateral forelimb control in the HB-NSC group from 6-10 weeks compared to the control group (p<0.05). [$^{18}F$]-FP-CIT microPET at 10 weeks posttransplantation demonstrated a significant increase in uptake in the HB-NSC group compared to pretransplantation (p<0.05). In IHC and IF staining, tyrosine hydroxylase and human ${\beta}2$ microglobulin (a human cell marker) positive cells were visualized at the transplant site. Conclusion : These results suggest that the HB-NSC aggregates can survive in the striatum and exert therapeutic effects in a PD model by secreting dopamine.

Study on Plans for the Establishment of Strategy on Climate Change Adaptation in Korea (국가 기후변화 적응 전략 수립 방안에 관한 연구)

  • Kwon, Won-Tae;Baek, Hee-Jeong;Choi, Kyung-Cheol;Chung, Hyo-Sang
    • Atmosphere
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    • v.15 no.4
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    • pp.213-227
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    • 2005
  • The global mean surface temperature has already increased by $0.6{\pm}0.2^{\circ}C$ over the last century, and warming in Korea is approximately twice as large as the global average. The Intergovernmental Panel on Climate Change (IPCC) has concluded that the majority of warming over the past 50 years could be attributed to human activities (IPCC, 2001a). In addition, the global surface temperature is expected to increase by 1.4 to $5.8^{\circ}C$ depending on the greenhouse gas emission scenarios during the $21^{st}$ century.Climate change resulting from increased greenhouse gas concentrations has the potential to harm societies and ecosystems. Reductions in emissions of greenhouse gases and their concentration in the atmosphere will reduce the degree and likelihood of significant adverse conditions due to the anticipated climate change. Mitigation policy has generally been the primary focus of public attention and policy efforts on climate change. However, some degree of climate change is inevitable due to the combination of continued increases in emissions and the inertia of the global climate system. Adaptation actions and strategies are needed for a complementary approach to mitigation. The United Nations Framework Convention on Climate Change (UNFCCC) currently addresses vulnerability and adaptation in the context of climate change negotiations and in future adaptation may be an important element of work under the Kyoto Protocol. There are several on-going programs to develop effective adaptation strategies and their implementation. But in general, many other countries are still on an initiating stage. The climate change science programs of the United States, Japan, England, and Germany are initiated to understand the current status of climate change science and adaptation researches in the developed countries. In this study, we propose the improvement on systems in policy and research aspects to effectively perform the necessary functions for development of nation-wide adaptation measures and their implementation. In policy aspect, the Korean Panel on Climate Change (KPCC) is introduced as a coordinating mechanism between government organizations related with climate change science, impact assessment and adaptation. Also in research aspect, there is a strong consensus on the need for construction of a national network on climate change research as trans-disciplinary research network.

Economic Assessment of the Battery Energy Storage System with Its Customer Type (수용가 형태에 따른 전지전력저장시스템의 경제성 평가)

  • 손학식;최준호;김재철
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.16 no.2
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    • pp.81-89
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    • 2002
  • The Battery Energy Storage System (BESS) has lots of advantages such as load leveling, quick response emergency power (spinning reserve), frequency and voltage control, improvement of reliability, and deferred generation and transmission construction. However, it is very critical that economic feasibility requires justification from the customer side of meter to promoting the dissemination of BESS in nation widely. In this paper, we proposed the economic assessment model of customer owned BESS which is complemented and improved the existing model. The proposed model is applied to the typical customer types, i.e. light industrial, commercial, and residential, which are taken from the statistical analysis on the load profile survey of Korea Electric Power COmpany (KEPCO). The economic viability performed for each customer load type to justifying their economic feasibility of BESS installation from the economic measures such as payback period, Net Present Worth (NPW), Rate Of Return (ROR). The results show that the BESS has economic benefits to the specific customer type, i.e. residential customer. Therefore, the government and the energy agency should be committing the support program, such as tax incentive, financial support, to disseminate the BESS nation widely. The results of this paper are useful to the customer investment decision-making and the national energy policy & strategy in Korea.

Investigation of Cognitive Model of Task Commitment on Biology Classification Inquiry (생물 분류 탐구에서 과제 집착의 인지적 모형 규명)

  • Kwon, Seung-Hyuk;Kwon, Yong-Ju
    • Journal of Science Education
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    • v.37 no.1
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    • pp.170-185
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    • 2013
  • The purpose of this study is to investigate a cognitive model of task commitment on biology classification inquiry. To achieve this goal, first, this study analyzed several literatures on task commitment in biology inquiry, and invented the tentative model of the task commitment. To investigate a tentative model invented, 2 main tasks were developed. These tasks were administered to 8 high-school students, first grade. Raw protocols were collected by thinking aloud method and a retrospective interview method. Collected protocols were converted to segmented protocols and coded by analyzing frame based invented model. The codes were analyzed. As a result, some problems were discovered, tentative model were revised. New analyzing frame based on Improved model were composed, and raw protocols were re-analyzed. Finally, a cognitive model of task commitment on biology classification inquiry was investigated. The investigated cognitive model of task commitment on biology classification inquiry was constructed 3 steps, 'Task commitment Induction', 'Task commitment Reinforcement', 'Task commitment Maintenance'. And each steps were consisted of several sub-factor. And commitment component were changed in each steps. Through this results, base information for strategy that improvement task commitment on biology classification inquiry is provided. Furthermore, the cognitive model of task commitment on biology classification inquiry will assist on evaluation and feedback by stage on task commitment.

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The Norwood Operation in Infants with Complex Congenital Heart Disease (복잡 선천성 심기형 환자에서의 Norwood 술식)

  • 박정준;김용진
    • Journal of Chest Surgery
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    • v.30 no.3
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    • pp.263-269
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    • 1997
  • From April 1987 to May 1996, 13 infants underwent a Norwood operation for complex congenital heart diseases including hypoplastic left heart syndrome (n : 7), mitral stenosis with small VSD and subaortic stenosis (n : 1), mitral atresia with ventricular septal defect, coarctation of aorta, and subaortic stenosis (n = 1), interrupted aortic arch with ventricular septal defect and subaortic stenosis (n : 1), tricuspid atresia with transposition of the great arteries (n = 1), and complex double-inlet left ventricle (n : 2). All patients without hypoplastic left heart syndrome were associated wit hypoplasia of ascending aorta and arch. Age at operation ranged from 3 days to 8.7 months (mean 60.6 $\pm$ 71.6 days, median 39 days). The operative mortality( < 30 days) was 46% (6 patients). Late mortality was 15% (2 patients). All operative deaths occured during the Erst 24 hours after the operation as a result of cardiopulmonary bypass weaning failure (5 patients) and sudden hemodynamic instability postoperatively (1 patient). Late death was due to aspiration pneumonia in two cases. There are 5 long-term survivals (39%). Three of them have undergone a two-stage repair with a modified Fontan operation in two and total cavopulmonary shunt in one at 12, 17, 4.5 months after Norwood procedure with no mortality. Two patients have entered a three-stage repair strategy by undergoing a bidirectional cavopulmonary shunt at 3 and 5.5 months after initial operation with 1 operative death. The actuarial survival rate for all patients at the first-stage operation, including hospital deaths and ate death was 30.8% at 1 year. In conclusion, the operative mortality of Norwood operation was relatively high compared to other operation for major cardiac anomalies, continuing experience will lead to an improvement in result.

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