검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 15

        1.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Plant-parasitic nematodes are the most devastating group of plant pathogens worldwide and are extremely challenging to control. In the present study, we have performed a genome wide analysis to identify common genes among four nematode species consisting of root-knot nematodes (Meloidogyne incognita and Meloidogyne hapla), cyst nematode (Heterodera glycines), and free living nematode (Caenorhabditis elegans) respectively. Using their whole genome sequences, we predicted 15,274 genes from M. incognita, 38,149 genes from M. hapla, 8,061 genes from H. glycines and 23,894 genes from C. elegans, where, among the predicted genes, 1,358, 1,350, 1,401, 1,365 respectively from each nematode, code for common groups of proteins. Further, 2,067, 2,086, 1,566, 2,903 genes were recollected using Clusters of Orthologous Groups (COG) database. Under our search criteria, a total of 800 common genes were identified in all the four studied nematode genomes. The most annotated conserved genes were obtained from four different species using Basic Local Alignment Searching Tool (BLAST). Uni- Prot Taxon identifier database was used to elucidate their taxonomic classification such as 698 genes under kingdom Metazoa, 660 genes confined to Nematoda, 290 genes in Chordata and 660 genes falling under class Chromadorea. The biochemical characterization of proteins expressed by these genes was examined using Pedant-Pro sequence analysis. The protein length, molecular weight, isoelectric point (pI), and transmembrane domain of the coded proteins were at a range of 300 to 999 amino acids (40.9%), molecular weight of over 100 kDa (96%), pI from 4.5 to 5.5 (27.6%) and 0 (56.6%), respectively. To classify protein function, the obtained BLAST hits were assigned to Gene Ontology classification scheme. The fractions of protein function were distributed as cellular component, biological processes and molecular function of the cell (22.2%), multicellular organism process (15.8%) and binding (48.3%), respectively. The current study provides an excellent resource for nematode functional genomics studies, which can be utilized further for studies on role of genes involved in nematode biological processes.
        4,000원
        5.
        2019.12 KCI 등재 서비스 종료(열람 제한)
        In the case of conventional soft robots, the basic stiffness is small due to the use of flexible materials. Therefore, there is a limitation that the load that can bear is limited. In order to overcome these limitations, a study on a variable stiffness method has been conducted. And it can be seen that the jamming mechanism is most effective in increasing the stiffness of the soft robot. However, the jamming mechanism as a method in which a large number of variable act together is not even theoretically analyzed, and there is no study on intrinsic principle. In this paper, a study was carried out to increase the stability of the force chain to increase the stiffness due to the jamming transition phenomenon. Particle size variables, backbone mechanisms were used to analyze the stability of the force chains. We choose a jamming mechanism as a variable stiffness method of a soft robot, and improve the effect of stiffness based on theoretical analysis, modeling FEM simulation, prototyping and experiment.
        6.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        As an interpretation of existing jamming effects, the main variables affecting the increase in stiffness due to jamming are known as system density, jamming density, pressure, and particulate temperature. The main variable, jamming density, is closely related to the distribution of particle size and contact properties such as particle shape and friction. However, the complexity of these variables makes it difficult to fully understand the mechanism of the jamming effect. In this paper, we focus on the jamming effects of particles that have more elastic properties than particles such as sand and coffee powder, which are commonly used as constituent particles of existing jamming, in order to reduce complicated factors such as temperature and concentrate on jamming effects based on elastic characteristics of particles. It was experimentally explored the possibility of increasing stiffness by mixing particles of different sizes rather than simply increasing the bending stiffness by controlling the particle size. Through simulations and experiments, we found a case where the stiffness of each particle size distribution is larger than the stiffness of each particle size.
        7.
        2016.08 KCI 등재 서비스 종료(열람 제한)
        Increasing interest of human health, building bio-database (Bio DB) has been become a hot issue in life science. Consequently, Single Cell Analysis (SCA) which can explain biodiversity of lives has been a significant factor for building Bio DB. In numerous studies from these analyses, they have been showed that mechanical properties of cells can serve explanation of biological heterogeneity and criterion of disease states. Therefore, measuring mechanical properties of cells have great potential to be used in bio-medical applications. However, traditionally, many researchers have undergone difficult and time consuming work because handling small sized cells usually requires high-skilled technique. Thus, this paper shows robotized stiffness measurement technique using fixed ended beam sensor, precision motorized stage and substrate which have wall structure.
        8.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to analyze willingness to pay (WTP) for organic agricultural products. To accomplish the objective of the study, a consumer survey was conducted. Based on the pilot survey results, parametric survival model was used to analyze the WTP for organic products. The estimation results showed that the WTP for organic agricultural products is 1.4-fold when compared with the conventional products, which is lower than the current price by about 30 percent. The analytical results also showed that such variables as gender, recognitions for organic agricultural products, and consumers’ income have very significant effects on the WTP, and that there are no differences among WTPs by consumption goals. Based on major findings, the most effective countermeasure was suggested for expanding of organic food consumption through the premium reduction of organic products. Reducing the costs of production and distribution, supporting farmers’ income by direct payment system were presented. Furthermore, it is needed to allocate more budget for promoting the consumption and distribution of organic agricultural products, and for enhancing conservation of agricultural environment.
        9.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        To realize a robot hand interacting like a human hand, there are many tactile sensors sensing normal force, shear force, torque, shape, roughness and temperature. This sensing signal is essential to manipulate object accurately with robot hand. In particular, slip sensors make manipulation more accurate and breakless to object. Up to now several slip sensors were developed and applied to robot hand. Many of them used complicate algorithm and signal processing with vibration data. In this paper, we developed novel principle slip sensor using separation layer. These two layers are moved from each other when slip occur. Developed sensor can sense slip signal by measuring this relative displacement between two layers. Also our principle makes slip signal decoupled from normal force and shear force without other sensors. The sensor was fabricated using the NBR(acrylo-nitrile butadiene rubber) and the Ecoflex as substrate and a paper as dielectric. To verify our sensor, slip experiment and normal force decoupling test were conducted.
        10.
        2016.05 KCI 등재 서비스 종료(열람 제한)
        An electro-hydraulic actuator (EHA) is widely used in industrial motion systems and the increasing bandwidth of EHA position control is important issue. The model-inverse feedforward controller is known to extend the bandwidth of system. When the system has non-minimum phase (NMP) zeros, direct model inversion makes system unstable. To overcome this problem, an approximate model-inverse method is used. A representative approximate model inversion method is zero phase error tracking control (ZPETC). However, if zeros locate right half plane of z-plane, the approximate inverse model amplifies the high-frequency response. In this paper, to solve the problem of ZPETC, an adaptive model-inverse control is proposed. The adaptive algorithm updates feedforward term in real-time. The effectiveness of the proposed adaptive model-inverse position control strategy is verified by comparison with typical proportional-integral (PI) control and feedforward control by experiments. As a result, the proposed adaptive controller extends the bandwidth of EHA position control.
        11.
        2010.08 KCI 등재 서비스 종료(열람 제한)
        In this paper, we present a global localization and position error compensation method in a known indoor environment using magnet hall sensors. In previous our researches, it was possible to compensate the pose errors of xe, ye, θe correctly on the surface of indoor environment with magnets sets by regularly arrange the magnets sets of identical pattern. To improve the proposed method, new strategy that can realize the global localization by changing arrangement of magnet pole is presented in this paper. Total six patterns of the magnets set form the unique landmarks. Therefore, the virtual map can be built by using the six landmarks randomly. The robots search a pattern of magnets set by rotating, and obtain the current global pose information by comparing the measured neighboring patterns with the map information that is saved in advance. We provide experimental results to show the effectiveness of the proposed method for a differential drive wheeled mobile robot.
        12.
        2009.08 KCI 등재 서비스 종료(열람 제한)
        In the high precision robot systems, the most popular tasks may be handling of micro-scale objects on a surface such as a micromanipulation robot system. In handling of micro-scale objects, the stiction effect becomes a fundamental issue since the micro-contact mechanics dominates the micromanipulation robot system. In the paper, a theoretical non-stick condition derived from the micro-contact mechanics is carried out for the propose of micro-scale object manipulation. To verify the non-stick condition, a micro-manipulation robot system equipped with a high precision stage system and a microscope system is developed. Experimental results show that the proposed non-stick condition guarantees successful micro-scale object manipulation.
        13.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        Recently, robotic automation in clinical laboratory becomes of keen interest as a fusion of bio and robotic technology. In this paper, we present a new robotic platform for clinical tests suitable for small or medium sized laboratories using mobile robots. The mobile robot called Mobile Agent is designed as transfer system of blood samples, reagents, microplates, and any instruments. Also, the developed mobile agent can perform diverse tests simultaneously based on its cooperative and distributed ability. The driving circuits for the mobile agent are embedded in the robot, and each mobile agent communicates with other agents by using Bluetooth communication. The RFID system is used to recognize patient information. Also, the magnetic hall sensor is embedded to remove and compensate the cumulated error of locomotion at the bottom of mobile agent. The proposed mobile agent can be easily used for various applications because it is designed to be compatible with general software development tools. The Mobile agents are manufactured, and feasibility of the robot and localization of the agents using magnetic hall sensor are validated by preliminary experiments.
        14.
        2006.09 KCI 등재 서비스 종료(열람 제한)
        Tactile sensation is one of the most important sensory functions for human perception of objects. Recently, there have been many technical challenges in the field of tactile display as well as tactile sensing. In this paper, we propose an innovative tactile display device based on soft actuator technology with ElectroActive Polymer(EAP). This device offers advantageous features over existing devices with respect to intrinsic flexibility, softness, ease of fabrication and miniaturization, high power density, and cost effectiveness. In particular, it can be adapted to various geometric configurations because it possesses structural flexibility, so it can be worn on any part of the human body such as finger, palm, and arm etc. It can be extensively applied as a wearable tactile display, a Braille device for the visually disabled, and a human interface in the future. A new design of the flexible actuator is proposed and its basic operational principles are discussed. In addition, a wearable tactile display device with 4x5 actuator array(20 actuator cells) is developed and its effectiveness is confirmed