• Title/Summary/Keyword: 물리기반

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Backward Path Tracking Control of a Trailer Type Robot Using a RCGS-Based Model (RCGA 기반의 모델을 이용한 트레일러형 로봇의 후방경로 추종제어)

  • Wi, Yong-Uk;Kim, Heon-Hui;Ha, Yun-Su;Jin, Gang-Gyu
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.9
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    • pp.717-722
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    • 2001
  • This paper presents a methodology on the backward path tracking control of a trailer type robot which consists of two parts: a tractor and a trailer. It is difficult to control the motion of a trailer vehicle since its dynamics is non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a real-coded genetic algorithm(RCGA) is proposed and a backward path tracking control algorithm is then obtained based on the linearized model. Experimental results verify the effectiveness of the proposed method.

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A Study on Root Damage to Street Pavement from the Roots of Roadside Trees in Urban Areas - Focusing on Roadside Trees in Seo-gu, Daejeon City - (도심 가로수 뿌리의 융기특성 연구 - 대전 서구 가로수를 대상으로 -)

  • Tak, Seong-Cheol;Lee, Shiyoung
    • Journal of the Korean Institute of Landscape Architecture
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    • v.46 no.3
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    • pp.58-69
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    • 2018
  • This study investigated root damage characteristics and correlations between roadside trees and street furniture through the investigation of the root damage conditions and the current status of roadside trees and street furniture in Seo-gu, Daejeon City where the occurrence of pavement uplift is frequent. The study area was divided into six areas by species of trees as Metasequoia glyptostroboides and Platanus occidentalis focusing on the streets that were installed with trees chest height and 8cm round planted at the time of the development of the Dunsan-dong Housing Site Development in Seo-gu, Daejeon metropolitan city (1990~1994). The damage rate of roadside protection frames (95.3%) was higher than that of curbstones (19.7%) at the study site. Streets without a protective frame were more likely to have damaged pavement. In addition, the frequency of breakage of protective frames was lowered when a drinking water area was increased to more than a certain level. The frequency of the type of uplift in the sidewalk pavement surfaces is in the order of tail type > mounding type > irregular type, and the frequency of the uplift direction is the highest in Direction 1 ($0{\sim}44^{\circ}C$), Direction 2 ($45{\sim}89^{\circ}$), and Direction 3 ($95{\sim}134^{\circ}$) when $180^{\circ}$ of the street direction is based on $90^{\circ}$ parallel to the curbstone. The uplift length is about 31~60cm and it is most often at a height of 3~6cm. When comparing the results of uplift deformation, Metasequoia glyptostroboides was found to be higher than the deformation of Platanus occidentalis. In addition, it can be seen that the larger the length, width and height of the ridge, the larger the deformation becomes. The relationship between the diameter at breast height, the dimension of the pavement width, the frequency of the ridge phenomenon and the deformation amount is not necessarily proportional, and there seems to be a gap due to external factors such as soil humidity and planting base. Therefore there is a need for a multi-directional approach in reducing uplift.

Characterization and Feasibility Study of the Soil Washing Process Applying to the Soil Having High Uranium Concentration in Korea (우라늄 함량이 높은 국내 토양에 대한 토양학적 특성 규명 및 토양세척법의 적용성 평가)

  • Chang, See-Un;Lee, Min-Hee
    • Journal of Soil and Groundwater Environment
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    • v.13 no.5
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    • pp.8-19
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    • 2008
  • The physicochemical properties of soils having high uranium content, located around Duckpyungri in Korea, were investigated and the lab scale soil washing experiments to remove uranium from the soil were preformed with several washing solutions and on various washing conditions. SPLP (Synthetic Precipitation Leaching Procedure), TCLP (Toxicity Characteristic Leaching Procedure), and SEP (Sequential Extraction Procedure) for the soil were conducted and the uranium concentration of the extracted solution in SPLP was higher than Drinking Water Limit of USEPA (30 ${\mu}g$/L), suggesting that the continuous dissolution of uranium from soil by the weak acid rain may generate the environmental pollution around the research area. For the soil washing experiments, the uranium removal efficiency of pH 1 solution for S2 soil was about 80 %, but dramatically decreased as pH of solution was > 2, suggesting that strong acidic solutions are available to remove uranium from the soil. For solutions with 0.1M of HCl and 0.05 M of ${H_2}{SO_4}$, their removal efficiencies at 1 : 1 of soil vs. washing solution ratio were higher than 70%, but the removal efficiencies of acetic acid, and EDTA were below 30%. At 1 : 3 of soil vs. solution, the uranium removal efficiencies of 0.1M HCl, 0.05 M ${H_2}{SO_4}$, and 0.5M citric acid solution increased to 88%, 100%, and 61% respectively. On appropriate washing conditions for S2 soil such as 1 : 3 ratio for the soil vs. solution ratio, 30 minute for washing time, and 2 times continuous washing, TOC (Total Organic Contents) and CEC (Cation Exchange Capacity) for S2 soil were measured before/after soil washing and their XRD (X-Ray Diffraction) and XRF (X-Ray Fluorescence) results were also compared to investigate the change of soil properties after soil washing. TOC and CEC decreased by 55% and 66%, compared to those initial values of S2 soil, suggesting that the soil reclaimant may need to improve the washed soils for the cultivated plants. Results of XRF and XRD showed that the structural change of soil after soil washing was insignificant and the washed soil will be partially used for the further purpose.

A Study on Fuel Quality Characteristics of F-T Diesel for Production of BTL Diesel (BTL 디젤 생산을 위한 F-T 디젤의 연료적 특성 연구)

  • Kim, Jae-Kon;Jeon, Cheol-Hwan;Yim, Eui-Soon;Jung, Choong-Sub;Lee, Sang-Bong;Lee, Yun-Je;Kang, Myung-Jin
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.3
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    • pp.450-458
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    • 2012
  • In order to reduce the effects of greenhouse gas (GHG) emissions, the South Korean government has announced a special platform of technologies as part of an effort to minimize global climate change. To further this effort, the Korean government has pledged to increase low-carbon and carbon neutral resources for biofuel derived from biomass to replace fossil and to decrease levels of carbon dioxide. In general, second generation biofuel produced form woody biomass is expected to be an effective avenue for reducing fossil fuel consumption and greenhouse gas (GHG) emissions in road transport. It is important that under the new Korean initiative, pilot scale studies evolve practices to produce biomass-to-liquid (BTL) fuel. This study reports the quality characteristics of F-T(Fischer-Tropsch) diesel for production of BTL fuel. Synthetic F-Tdiesel fuel can be used in automotive diesel engines, pure or blended with automotive diesel, due to its similar physical properties to diesel. F-T diesel fuel was synthesized by Fischer-Tropsch (F-T) process with syngas($H_2$/CO), Fe basedcatalyst in low temperature condition($240^{\circ}C$). Synthetic F-T diesel with diesel compositions after distillation process is consisted of $C_{12}{\sim}C_{23+}$ mixture as a kerosine, diesel compositions of n-paraffin and iso-paraffin compounds. Synthetic F-T diesel investigated a very high cetane number, low aromatic composition and sulfur free level compared to automotive diesel. Synthetic F-T diesel also show The wear scar of synthetic F-T diesel show poor lubricity due to low content of sulfur and aromatic compounds compared to automotive diesel.

A Study on the Effects of the Characteristics of Franchise Business Members on Affiliate Outcomes (업종별 프랜차이즈 선택결정요인이 가맹점 성과의 만족도와 성공·실패에 미치는 영향연구)

  • Jang, Jae-Nam;Kang, Chang-Dong;Ahn, Sung-Sik
    • Journal of Distribution Science
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    • v.9 no.2
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    • pp.49-59
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    • 2011
  • A franchise can be said to be the main method of distribution and marketing. It appears to be the future of the retail industry and is one of the world's fastest growing businesses sectors, as many policy reports and research results have acknowledged. Korea's franchise industry began in the 1970s, spread out into many areas (including food services, retail, and the service industry), and has grown by over 10% each year ever since. The industry's influence on the national economy becomes ever greater. Although the size of the franchise industry is expected to grow as it spreads and as the government expands its support, it has not yet attracted much academic interest. Research has so far been very fragmented. The main interest has been the relationship and conflicts between the head offices and the affiliates. No study has yet occurred on whether the concepts of satisfaction and intent to conclude a contract directly affect the success or failure of the affiliates. Few studies have empirically inquired into the demographic characteristics and abilities of the affiliates that significantly affect their results. Domestic franchise industries must prepare to leap from quantitative to qualitative growth. Most important is the need for affiliate headquarters and affiliates to build confidence between them. A friendly and reliable relationship between affiliate headquarters and affiliates will eliminate distrust from the franchise and maintain a healthy franchise system. This study suggests that current and prospective heads of affiliation should concentrate not on attracting affiliates but on investment and techniques of affiliate support. They should work on the reinforcement of brand power, the appropriate affiliate business environment, systematic education/training, taking burdens off the affiliate business persons, consolidating the relationship with the affiliate business persons, marketing mix factors (e.g. products, price conditions, logistics and shipping services, promotion, supervising and supervisor, operation procedures/processes, and material evidence); these all greatly affect the success or failure of the affiliate business. Supporting the affiliates is an important factor that enhances their results and satisfaction and consequently increases the positive recommendations to others and the ratio of recurrent conclusions of contracts, which ultimately generate the growth of the franchises. In addition, it is suggested that prospective franchise founders should make every effort to choose a good head office since the characteristics of the head office greatly influence the success of the affiliates. This study is significant in that it grasps the characteristics of the head office of affiliation and of the affiliates that influence affiliate results in ways not yet academically attempted.

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A Look at the Need for a Crafts program of Developmental Disabilities (발달장애의 수예공작 프로그램 필요성에 관한 고찰)

  • Kim, Nam-Soon;Kim, Dong-Hyun;Kim, Hee-Jung
    • The Journal of Korean society of community based occupational therapy
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    • v.1 no.1
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    • pp.79-89
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    • 2011
  • The number of the disabled person had been increased for the industrial accident and the environmental pollution. Especially, developmental disability has the high prevalence rate between 5% and 10% of the whole children. The children with a developmental disability can be treated by the physical therapy, the occupational therapy, the psychology therapy, speech therapy, and art therapy. Visual preception which is function to recognize the external environment through the optic organ could be related to most behaviors on the everyday life. But because the children with disability could not develop the visual-preception enough, they came to have difficulties in executing daily life project. For this reason, it is most important to understand the estimation and the cure on the visual-preception in the pediatric occupational therapy. To improve the visual-preception power, we have many kind of methods including sensory integration, training program for the visual-perception and art-craft program. Particularly, the art-craft which is the representative activity for making something by hands, can be applied to anyone. As the study on the brain has been activated, it was proved that handicraft actives could have an good effect on the brain function and using brain. When the fine motor exercise and more delicate and accurate motion were carried, these motions need the essential help of the visual-perception. So it could be expected that using the repetitive hand function by art-craft makes the brain function improve, when a activity that needs a fine motor exercise and more delicate, accurate motion was carried, It also indicates that the art-craft program has a clear treatment value. Though the intervention between visual-perception development and visual-perception disability have a majority in the field of occupational therapy, there is a few study yet. Therefore, this study tried to look back on the necessity of applying the art-craft program to the children with disability as the prestudy for preliminary validity of the master's thesis.

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Urban Landscape Image Study by Text Mining and Factor Analysis - Focused on Lotte World Tower - (텍스트 마이닝과 인자분석에 의한 도시경관이미지 연구 - 롯데월드타워를 대상으로 -)

  • Woo, Kyung-Sook;Suh, Joo-Hwan
    • Journal of the Korean Institute of Landscape Architecture
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    • v.45 no.4
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    • pp.104-117
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    • 2017
  • This study compares the results of landscape image analysis using text mining techniques and factor analysis for Lotte World Tower, which is the first atypical skyscraper building in Korea, and identifies landscape images of the site to determine possibilities of use. Lotte World Tower's landscape image has been extracted from text mining analysis focusing on adjectives such as 'new', 'transformational', 'unusual', 'novelty', 'impressive', and 'unique', and phrases such as in the process of change, people's active elements(caliber, outing, project, night view), media(newspaper, blog), and climate(weather, season). As a result of the factor analysis, factors affecting the landscape image of Lotte World Tower were symbolic, aesthetic, and formative. Identification, which is a morphological feature, has characteristics of scale and visibility but it is not statistically significant in preference. Rather, the psychological factors such as the symbolism with characteristics such as poison and specialty, harmony with the characteristics of the surrounding environment, and beautiful aesthetic characteristics were an influence on the landscape image. The common results of the two research methods show that psychological characteristics such as factors that can represent and represent the city affect the landscape image more greatly than the morphological and physical characteristics such as location and location of the building. In addition, the text mining technique can identify nouns and adjectives corresponding to the images that people see and feel, and confirms the relationship between the derived keywords, so that it can focus the process of forming the landscape image and further the image of the city. It would appear to be a suitable method to complement the limitation of landscape research. This study is meaningful in that it confirms the possibility that big data can be utilized in landscape analysis, which is one research field of landscape architecture, and is significant for understanding the information of a big data base and contribute to enlarging the landscape research area.

Intra-laboratory Validation of an HPLC Post-column Oxidation Method for the Analysis of PSP Toxins in Oysters and Mussels (굴과 진주담치 중 마비성 패류독소 분석을 위한 HPLC post-column oxidation method의 시험소 내 유효성 검증)

  • Song, Ki Cheol;Lee, Ka-Jeong;Yu, Hong-Sik;Mok, Jong-Soo;Kim, Ji Hoe;Lim, Keun-Sik;Lee, Mi-Ae;Kim, Mee-Hye
    • Korean Journal of Food Science and Technology
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    • v.45 no.2
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    • pp.241-247
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    • 2013
  • AOAC Mouse Bioassay Analysis (MBA) has been the gold standard for the analysis of paralytic shellfish poisoning toxin (PSP toxin) for more than 50 years. However, this method has inaccurate limit of quantification and cannot be used to determine toxic profiles. An HPLC method (PCOX) was optimized for Korean shellfish to establish an alternative or supplementary method for PSP analysis and was intended to be used for the official monitoring and regulation of food. The recovery rate of the PCOX method was 83.5-112.1% and the limit of quantification for total toxin was about $8.6{\mu}g$/100 g. A long-term comparison study showed a good correlation of the PCOX results with the AOAC MBA results: the correlation factors were 0.9534 and 0.9109 for oyster and mussel matrices, respectively. The PCOX method may be used as an alternative or supplementary method for AOAC MBA to monitor the occurrence of PSP and to analyze PSP toxin profile in oysters and mussels.

An Analysis of Process-oriented Design in the Invited Entries of International Competition for the Master Plan of the Yongsan Park, Korea (용산공원 설계 국제공모 출품작에 나타난 프로세스적 설계 분석)

  • So, Jin;Sung, Jong-Sang;Pae, Jeong-Hann
    • Journal of the Korean Institute of Landscape Architecture
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    • v.41 no.2
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    • pp.11-26
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    • 2013
  • Designing large parks such as Yongsan Park requires the open-ended process-oriented design approach in complex layers rather than the conventional self-completed master plan method. This study aims to examine the characteristics of process-oriented design in the eight invited entries of "International Competition for the Master Plan of the Yongsan Park, Korea"(2012). For this purpose, it analyzed each entry according to three criteria: objects of process-oriented approach, time factor and its features of phasing plan, and presentation method of the process. This analysis can not only critically review the current level of the process-centered design methodology but also suggest strategic future directions for Yongsan Park. The objects of process-oriented design in the eight works were order of physical space development, restoration process of ecosystem, recovering process of publicity, and economic operation and management. Main considerations in the objects were connections to adjacent urban fabrics, links to regional green and water system, reuse of existing buildings and infrastructures in the site. The temporal criteria of the phasing plan had two aspects. One was planning a certain time and period, and the other was just establishing an order of phases. Most of the presentation method of process was the phasing plan, but some of the entries suggested a scenario plan. The eight works of "International Competition for the Master Plan of Yongsan Park" did not attempt process-oriented designs entirely and completely. Rather, they tried to introduce the phasing plan as part of a process-centered design. Also, they took an eclectic approach between master plan and process-oriented design instead of rejecting the conventional master plan approach.

Review of Remote Sensing Studies on Groundwater Resources (원격탐사의 지하수 수자원 적용 사례 고찰)

  • Lee, Jeongho
    • Korean Journal of Remote Sensing
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    • v.33 no.5_3
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    • pp.855-866
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    • 2017
  • Several research cases using remote sensing methods to analyze changes of storage and dynamics of groundwater aquifer were reviewed in this paper. The status of groundwater storage, in an area with regional scale, could be qualitatively inferred from geological feature, surface water altimetry and topography, distribution of vegetation, and difference between precipitation and evapotranspiration. These qualitative indicators could be measured by geological lineament analysis, airborne magnetic survey, DEM analysis, LAI and NDVI calculation, and surface energy balance modeling. It is certain that GRACE and InSAR have received remarkable attentions as direct utilization from satellite data for quantification of groundwater storage and dynamics. GRACE, composed of twin satellites having acceleration sensors, could detect global or regional microgravity changes and transform them into mass changes of water on surface and inside of the Earth. Numerous studies in terms of groundwater storage using GRACE sensor data were performed with several merits such that (1) there is no requirement of sensor data, (2) auxiliary data for quantification of groundwater can be entirely obtained from another satellite sensors, and (3) algorithms for processing measured data have continuously progressed from designated data management center. The limitations of GRACE for groundwater storage measurement could be defined as follows: (1) In an area with small scale, mass change quantification of groundwater might be inaccurate due to detection limit of the acceleration sensor, and (2) the results would be overestimated in case of combination between sensor and field survey data. InSAR can quantify the dynamic characteristics of aquifer by measuring vertical micro displacement, using linear proportional relation between groundwater head and vertical surface movement. However, InSAR data might now constrain their application to arid or semi-arid area whose land cover appear to be simple, and are hard to apply to the area with the anticipation of loss of coherence with surface. Development of GRACE and InSAR sensor data preprocessing algorithms optimized to topography, geology, and natural conditions of Korea should be prioritized to regionally quantify the mass change and dynamics of the groundwater resources of Korea.