• Title/Summary/Keyword: 다가

Search Result 15,994, Processing Time 0.035 seconds

Rank-based Formation for Multiple Robots in a Local Coordinate System (지역 좌표에서 랭크기반의 다개체 로봇 포메이션 제어)

  • Jung, Hahmin;Kim, Dong Hun
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.25 no.1
    • /
    • pp.42-47
    • /
    • 2015
  • This paper presents a rank-based formation for multiple agents based on potential functions, where the proposed method uses the relative position of two neighboring agents. The conventional formation scheme of multiple systems requires communication between agents and a central computer to get the positions of all multiple agents. In the study, differently from previous studies, the formation scheme uses the relative position of two neighboring agents in a local coordinate system. In addition, it introduces a singular agent association that considers only the relative position between an agent and its neighboring agents, instead of multiple associations among all information about all agents. Furthermore, the proposed framework explores the benefits of different formation types. Extensive simulation results show that the proposed approach verifies the viability and effectiveness of the proposed formation.

Performance Analysis of Broadband Spread Spectrum Method Against Multipath Fading (광대역 대역환산 방식의 다경로 페이딩에 대한 성능 평가)

  • 신철호;김광식;김철성
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.7 no.5
    • /
    • pp.408-417
    • /
    • 1996
  • In this paper, we quantiatively analyze the broadband CDMA systems with high chip rate, which virually eliminates the multipath fading effects by distinguishing each reflected paths in the process of despreading. We model the broadband multipath propagation channel with random time-variant impulse response as a linear filter of tapped delay line to evaluate the performance of broadband CDMA systems in multipath fading environment. This statistical model, based on extensive experimental data, was established to characterize the urban radio propagation medium in various environments. We perform computer simulation of the transmission and reception of broadband CDMA systems by applying it to abve channel model. From the simulation results, we confirm that the broadband CDMA systems inherenly reduce the effects of multipath fading phenomena which causes to degrade the performance of mobile communication systems, based on the results of eye-diagram and BER curve.

  • PDF

Improvement of Water Resistant Properties of a Linerboard for Corrugated Fiberboard Box by Coating with Na-alginate (알긴산 코팅에 의한 골판지 상자 제조용 라이너 원지의 수분저항성 증진)

  • Kim, Eun-Jung;Rhim, Jong-Whan;Kim, Byung-Yong
    • Korean Journal of Food Science and Technology
    • /
    • v.38 no.6
    • /
    • pp.762-766
    • /
    • 2006
  • To improve water resistance of paperboard used to manufacture the corrugated boxes, effect of surface coating of the liner- board with Na-alginate was investigated by determining the optimum processing conditions such as a optimum alginate concentration for surface coating, plasticizer content, concentration of divalent cations their immersion times, For the surface coating of the liner-board, 2.5% Na-alginate solution was found to be the optimum concentration, and the concentration of glycerol used as plasticizer was effective when 35% alginate concentration was use was Used Immersion of the alginate coated paperboard for 3 min in a $CaCl_2$ solution improved the water resistance properties. As a divalent cation for the insolubilization of the alginate films, $Cu^{2+}$ was found to be as effective as $Ca^{2+}$. Among the platicizers tested, sorbitol was the most effective in reducing water vapor permeability and water solubility of alginate coated paperboard.

Initial Equilibrium State Analysis of Cable Members for Preliminary Analysis of Multi-span Suspension Bridge under Dead Load (고정하중을 받는 다경간 현수교의 예비해석을 위한 케이블 부재의 초기평형상태 해석)

  • Choi, Dong-Ho;Na, Ho-Sung;Gwon, Sun-Gil
    • KSCE Journal of Civil and Environmental Engineering Research
    • /
    • v.36 no.1
    • /
    • pp.21-29
    • /
    • 2016
  • This paper proposes a method to determine the initial equilibrium state of cable members for preliminary analysis of multi-span suspension bridge under dead load. The proposed method is simpler and more practical than the previous methods used in other studies. The proposed method can be applied to three-span or multi-span suspension bridges. To verify the proposed method, an three-span model as well as four-span models such as New Millenium Bridge in Korea and Yingwuzhou Bridge in China are analyzed. In the verification results, the initial coordinates and tensions of the members calculated by the proposed method are good agreement with those in the previous study for the three-span model and those in the design data of New Millenium Bridge. In addition, the proposed method gives the initial values to keep the initial configuration of Yingwuzhou Bridge.

Accuracy of Fire of a Mortar via Multibody Dynamics Analysis (다물체 동역학 해석을 통한 포의 사격정확도 분석)

  • Jin, Jae Hoon;Jung, Samuel;Kim, Tae Yoon;Kim, Young Ku;Ahn, Chang Gi;Yoo, Wan Suk
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.40 no.2
    • /
    • pp.229-236
    • /
    • 2016
  • For this research, the trajectory of a projectile was simulated via the multibody dynamics analysis of a self-propelled mortar. The dynamic model was composed of a mortar model and a vehicle model, and was simulated using the RecurDyn program. Interior ballistic was applied to the mortar model, and exterior ballistic was conducted by Matlab using the simulation results of the interior trajectory. Through repetitive Monte-Carlo simulations, the accuracy of the mortar was analyzed by considering variations in the aiming angle and vehicle dynamic response.

Development of Multi-Body Dynamics Simulator for Bio-Mimetic Motion in Lizard Robot Design (도마뱀 로봇 설계를 위한 생체운동 모사 다물체 동역학 시뮬레이터 개발)

  • Park, Yong-Ik;Seo, Bong Cheol;Kim, Sung-Soo;Shin, Hocheol
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.38 no.6
    • /
    • pp.585-592
    • /
    • 2014
  • In this study, a multibody simulator was developed to analyze the bio-mimetic motion of a lizard robot design. A RecurDyn multibody dynamics model of a lizard was created using a micro-computerized tomography scan and motion capture data. The bio-mimetic motion simulator consisted of a trajectory generator, an inverse kinematics module, and an inverse dynamics module, which were used for various walking motion analyses of the developed lizard model. The trajectory generation module produces spinal movements and gait trajectories based on the lizard's speed. Using the joint angle history from an inverse kinematic analysis, an inverse dynamic analysis can be carried out, and the required joint torques can be obtained for the lizard robot design. In order to investigate the effectiveness of the developed simulator, the required joint torques of the model were calculated using the simulator.

Factors Influencing Emotional and Behavioral Characteristics of Children in Multicultural Families (다문화 가정 아동의 정서행동적 특성에 영향을 미치는 요인)

  • Jeon, Hae-In;Jung, Pyung-Gang;Lee, Hye-Kyung
    • The Journal of the Korea Contents Association
    • /
    • v.17 no.10
    • /
    • pp.149-160
    • /
    • 2017
  • The purpose of this study was to examine factors influencing emotional and behavior characteristics among children in multicultural families. The factors include demographic and psychological characteristics of married immigrant women. Surveys were distributed to 200 married immigrant women and, 148 surveys were returned and analyzed. The findings are as follows: first, emotional and behavioral characteristics of children were significantly associated with the age of their mothers and household income. Second, acculturative stress in married immigrant women was significantly related to the overall behavior characteristics of their children. Third, children whose mothers experienced a higher level of acculturative stress and were of older age showed internalizing problems. The level of Korean language proficiency and marital satisfaction were also important factors influencing sub-categories of internalizing and externalizing problems aside from acculturative stress. Implications and suggestions to develop preventative programs for emotional and behavioral problems of children in multicultural families are discussed.

Cultural Contents Development Case Study and Using Plan of Participation-based (참여 기반의 문화콘텐츠 개발 사례 분석 및 활성화 방안)

  • Na, Yun-Bin;Kwon, Hyeog-In;Lee, Seoung-Ha
    • The Journal of the Korea Contents Association
    • /
    • v.14 no.2
    • /
    • pp.113-121
    • /
    • 2014
  • Domestically multicultural society is being demanded a change in recognition today into the direction of harmony from assimilation. This change in paradigm is having a proposition as understanding about mutually different cultural background. A role of cultural contents is getting important more than ever as a link of understanding and recognition between heterogeneous groups. These cultural contents can be enhanced its effect when being developed on the basis of cooperation by which the multi-cultural members themselves participate in a project, and can conform even with social significance. The purpose of this study is to analyze a project case of a multicultural contents planning team 'Arto Placo', which produced contents through cooperation between a foreigner group including marriage immigrants and a local group such as illustrator and children's book writer. Each project was indicated to be contents such as public performance, exhibition, ad APP book. The aim was to specifically examine Case Selection and Introduction, Contents's Planning Development, Assessment and Activation plan.

Isolation of Antibiotics Effective to Multidrug-Resistant Cancer Cells from Sorangium cellulosum(Myxobacteria). (점액세균 Sorangium cellulosum이 생산하는 약제내성 암세포의 증식억제물질)

  • 안종웅;이정옥
    • Microbiology and Biotechnology Letters
    • /
    • v.32 no.1
    • /
    • pp.47-51
    • /
    • 2004
  • Drug resistance is one of the most significant impediments to successful chemotherapy of cancer. Multidrug-resistance Is characterized by decreased cellular sensitivity to anticancer agents due to the overexpression of P-glycoprotein. By using adriamycin-resistance CL02 cancer cells, we undertook the screening fur agents which were effective to multidrug-resistant cancer cells from strains of the species Sorangium cellulosum isolated in our laboratory. Sorangium cellulose, cellulose-degrading myxobacteria have recently proved to be a rich source of novel anticancer agents. One of the significant examples is the promising anticancer agent epothilone. JW 1006 is the first strain of Sorangium cellulosum which was selected by us for the isolation of a metabolite by a biological screening because of a high cytotoxic activity against the CL02 cancer cells. Cytotoxicity-guided chromatographic fractionation of the culture broth led to the Isolation of two active principles, disorazole $A_1$ and $A_2$. They showed potent cytotoxicity against CL02 cancer cells with $IC_{50}$ values in the picomolar range, and were as active against drug-resistant cancer cells CL02 and CP70 as against the corresponding sensitive cells.

A Study of Evaluating the KSL Textbook for Students with Multicultural Backgrounds (다문화 학생을 위한 제2언어로서의 한국어교재 평가 연구)

  • Chang, Kyungsuk;Go, Youngsan;Jeon, Young-Joo
    • The Journal of the Korea Contents Association
    • /
    • v.16 no.10
    • /
    • pp.33-46
    • /
    • 2016
  • The present study aims to investigate how teachers evaluate the Korean textbook they use for teaching primary students with multicultural background. Faced with the rich variety of materials available, it is often a challenging task for language teachers to select the most suitable coursebook. It is required that they carry out a detailed and comprehensive analysis of coursebooks and evaluate them with a set of criteria to guide the process. 32 Korean teachers took part in the primary KSL textbook evaluation that aimed to identify improvement areas. They used a pro-forma specified with 51 criteria. The teachers' responses to the questions in the pro-forma were statistically analyzed to draw implications for material evaluation. The findings of the analysis suggest that the KSL textbook for primary multicultural students need to be improved at the internal and external levels. Implications are discussed with focus on material evaluation and development, and KSL teacher professional development by helping them gain good and useful insights into the nature of the textbook, and sensitizing them to features to look for in teaching and learning materials.