• Journal of Institute of Control, Robotics and Systems
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• v.22 no.10
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• pp.817-825
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• 2016

In this paper, we introduce a flexible gripper that we have engineered to precisely pinch in parallel and compliantly grasp objects. As found in most conventional industrial grippers, the parallel pinching property is essential for precise manipulation. On the other hand, the grippers with a flexible structure are more adept at grasping objects with arbitrary shapes and softness. To achieve these disparate properties, we introduce a flexible gripper mechanism composed of multiple flexible beam structures. Utilizing these beam structures, the proposed gripper is able to grasp arbitrarily shaped objects. Additionally, a unique combination of flexible beams enables the gripper to pinch objects using the parallel fingertips for enhanced precision. A detailed description of the proposed mechanism is provided, and an analysis of the strength and stiffness of the fingertip and finger body is presented. The Results section compares the theoretical and experimental analyses and verifies the properties and performance of the proposed gripper.

• Polymer(Korea)
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• v.31 no.2
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• pp.111-116
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• 2007

Polyurethane modified acrylate $(PUA)/SiO_2$ hybrid films were prepared by ultraviolet curing and their surface properties were investigated by hardness and adhesion test. The films were examined by the manipulation of mole-ratio of organic to inorganic components. Under the silica content controlled, highly desirable films were achieved and scratch resistance and hardness property of film were also enhanced, which indicates that the crosslinked silica particles are homogeneously dispersed within PUA film.

• Journal of Embryo Transfer
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• v.28 no.2
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• pp.121-125
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• 2013

This study was carried out to investigate the general characteristics of semen such as semen volume, pH, sperm motility and sperm concentration of the semen collected from Shih Tzu dogs (age of 24 to 48 months, weight of 4 to 8 kg) by using the method of digital manipulation of the penis. The effect of preservation temperature and time on motility of fresh semen was also investigated in the present study. Semen was collected for 16 times from 4 male Shih Tzu dogs by multiple ejaculations (four times ejaculation per dog). The average of semen volume, semen pH, sperm motility and sperm concentration of the second fraction containing small volume of the initial third fraction per ejaculation were $2.11{\pm}0.31$ ml, $6.25{\pm}0.07$, $97.59{\pm}1.03%$ and $2.05{\pm}0.14{\times}10^8$ cells/ml, respectively. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the first fraction from the ejaculation were $1.12{\pm}0.15$ ml, $5.99{\pm}0.14$, $16.09{\pm}6.18%$ and $5.16{\pm}2.03{\times}10^5$ cells/ml, respectively. Those of second fraction were $2.07{\pm}0.29$ ml, $6.36{\pm}0.13$, $97.31{\pm}1.36%$ and $2.15{\pm}0.30{\times}10^8$ cells/ml, respectively. Those of third fraction were $2.60{\pm}0.29$ ml, $6.63{\pm}0.08$, $95.72{\pm}1.61%$ and $6.03{\pm}1.83{\times}10^7$ cells/ml, respectively. Sperm motility was significantly higher at $17^{\circ}C$ preservation temperature than at $5^{\circ}C$ or $36^{\circ}C$ during preservation period except 1 h preservation (P<0.05). When preservation temperature was $17^{\circ}C$, sperm motility was $96.69{\pm}1.49%$ at 1 h, $91.38{\pm}1.90%$ at 6 h, $88.38{\pm}2.34%$ at 12 h, $78.13{\pm}4.58%$ at 18 h, $58.44{\pm}8.57%$ at 24 h and $29.56{\pm}5.06%$ at 30 h, respectively.

• KIPS Transactions on Computer and Communication Systems
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• v.8 no.9
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• pp.217-224
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• 2019

Recently, sensor networks are built and used on many kinds of fields such as home, traffic, medical treatment and power grid. Sensing data manipulation on these fields could be a serious threat on property and safety. Thus, a proper way to block sensing data manipulation is necessary. In this paper, we propose IoT(Internet of Things) sensing data validation mechanism based on data obfuscation and variance analysis to remove manipulated sensing data effectively. IoT sensor device modulates sensing data with obfuscation function and sends it to a user. The user demodulates received data to use it. Fake data which are not modulated with proper obfuscation function show different variance aspect with valid data. Our proposed mechanism thus can detect fake data by analyzing data variance. Finally, we measured data validation time for performance analysis. As a result, block rate for false data was improved by up to 1.45 times compared with the existing technique and false alarm rate was 0.1~2.0%. In addition, the validation time on the low-power, low-performance IoT sensor device was measured. Compared to the RSA encryption method, which increased to 2.5969 seconds according to the increase of the data amount, the proposed method showed high validation efficiency as 0.0003 seconds.

• Journal of Korea Multimedia Society
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• v.15 no.1
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• pp.148-165
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• 2012

Applying maintenance simulation using virtual mockup in product design phase enables maintainability test before prototyping physical products, and it is expected to reduce product development costs. The simulation results can be reused as contents of service manuals and RAM (Reliability, Availability, Maintainability) analysis data. Maintenance simulation should provide realistic representation of physical property of virtual product, assembly relation between parts and manipulation process to verify feasibility of product design. The simulation system should be extended to collaborative virtual environment to perform collaborative maintenance procedures. In this paper, the three layered system architecture and the physics based collaborative interaction technique are proposed to extend current maintenance simulation into collaborative virtual environment. The proposed system was implemented as ViMMS (Virtual Mockup Maintenance Simulation system), and compared with case study results of VADE (Virtual Assembly Design Environment). As a result, the ViMMS encompassed broader range of maintenance tasks by using physics based collaborative interaction technique.

• Korean Journal of Animal Reproduction
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• v.21 no.4
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• pp.405-409
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• 1997

This study was carried out to investigate the general characteristics such as semen volume, pH, sperm motility and sperm concentration of the semen collected from Korean Jindo dogs by the mothod of Digital manipulation of penis, and the effect of temperature and preservation time on motility of fresh semen. Multiple ejaculates were collected from four male Korean Jindo dogs. The results obtained in this experiment were as follows : 1. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the second fraction and the small volume of third fraction from the ejaculate were 3.29ml, 6.30, 96.70% and 1.64$\times$108 cells/ml, respectively. 2. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the first fraction from the ejaculate were 1.16ml, 6.10, 6.67% and 5.07$\times$105cells/ml. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the second fraction from the ejaculate were 2.30ml, 6.33, 97.66% and 1.92$\times$108cells/ml. Average semen volume per ejaculate, semen pH, sperm motility and sperm concentration of the third fraction from the ejaculate were 3.24ml, 6.51, 93.33% and 3.13$\times$107cells/ml. 3. Motility of fresh semen during preservation were higher at 17$^{\circ}C$ than at 5$^{\circ}C$ or 36$^{\circ}C$. When preservation temeprature was 17$^{\circ}C$, motility were 95.75% at 1 h, 90.00% at 6 h, 84.25% at 12 h, 68.00% at 18 h, 36.25% at 24 h and 28.75% at 30 h, respectively.

• Korean Journal of Poultry Science
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• v.27 no.1
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• pp.73-78
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• 2000

Embryonic stem (ES) cells are pluripotent cell lines, which derived from preimplantation embryo. These cells have been used as a vehicle of foreign DNA for production of transgenic mammals. this experiment was performed to examined the possible use of blastodermal cells derived from hen's egg for germline manipulation. Stage X blsdtodermal cells isolated from fertilized eggs were cultured in DMEM containing 15% fetal calf serum. Blastodermal cells wre co-cultured on the chicken embryonic fibroblast (CEF) or mouse embryonic fibroblast(MEF) cells. to examine the effects of growth factors on stem cell growth, bFGF and LIF were added. There was no significant difference in colony formation of putative ES cells between CEF and MEF as a feederlayer, but the addition of growth factors enhanced the proliferation and inhibited differentiation of blastodermal cells. To characterize the cell colonies as a putative ES cells, putative embryonic cell colonies were stained by periodic acid Schiffs (PAS) reagent. The putative ES cell colonies showed intensive positive reaction similar to the property of undifferentiated PGC upto 20days in vitro, but not in other cell types. this result demonstrates that PAS-positive cell colonies may be used for the study of establishment of chicken ES cell lines for the production of transgenic chicken.

• 한국HCI학회:학술대회논문집
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• 2009.02a
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• pp.363-367
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• 2009

We propose Cubical User Interface(CUI) for toy block composition in Augmented Reality. The creation of new object by composing virtual object is able to construct various AR contents effectively. However, existing GUI method requires learning time or is lacking of intuitiveness between act of user and offered interface. In case of AR interfaces, they mainly have been supported one handed operation and it did not consider composition property well. Therefore, the CUI provide tangible cube as the manipulation tool for virtual toy block composition in AR. The tangible cube which is attached multi-markers, magnets, and buttons supports free rotation, combination, and button input. Also, we propose two kinds of two-handed composing interactions based on CUI. First is Screw Driving(SD) method which is possible to free 3-D positioning and second is Block Assembly(BA) method which support visual guidance and is fast and intuitive. We expected that proposed interface can apply as the authoring system for content such as education, entertainment, Digilogbook.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.11
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• pp.3213-3217
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• 2009

Distribution, duplication and manipulation of the digital contents are very easy due to the characteristics of the digital contents. Thus, damages of invasion of property right rapidly increase due to infringement of copyright for the digital contents. To prevent illegal use and to settle conflict about ownership of the digital contents, continuous efforts with enormous expense are devoted. In this paper, we design and implement real-time audio watermarking system to protect ownership and copyright for the digital contents. The proposed system also clarifies where the responsibility about the illegal distribution lies. The system has convenient user interface so that general administrator without an expert knowledge of the protection of copyright can use easily. In addition, unlike the traditional watermarking system, our system has merit to offer information about the illegal distribution for clear post-management.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.394-394
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• 2013

The spin-orbit interaction has received great attention in the field of spintronics, because of its property and applicability. For instance, the spin-orbit interaction induces spin precession which is the key element of spin transistor proposed by Datta and Das, since frequency of precession can be controlled by electric field. The spin-orbit interaction is classified according to its origin, Dresselhaus and Rashba spin-orbit interaction. In particular, the Rashba spin-orbit interaction is induced by inversion asymmetry of quantum well structure and the slope of conduction band represents the strength of Rashba spin-orbit interaction. The strength of spin-orbit interaction is experimentally obtained from the Shubnikov de Hass (SdH) oscillation. The SdH oscillation is resistance change of channel for perpendicular magnetic field as a result of Zeeman spin splitting of Landau level, quantization of cyclotron motion by applied magnetic field. The frequency of oscillation is different for spin up and down due to the Rashba spin-orbit interaction. Consequently, the SdH oscillation shows the beat patterns. In many research studies, the spin-orbit interaction was treated as a tool for electrical manipulation of spin. On the other hands, it can be considered that the Rashba field, effective magnetic field induced by Rashba effect, may interact with external magnetic field. In order to investigate this issue, we utilized InAs quantum well layer, sandwiched by InGaAs/InAlAs as cladding layer. Then, the SdH oscillation was observed with tilted magnetic field in y-z plane. The y-component (longitudinal term) of applied magnetic field will interact with the Rashba field and the z-component (perpendicular term) will induce the Zeeman effect. As a result, the strength of spin-orbit interaction was increased (decreased), when applied magnetic field is parallel (anti-parallel) to the Rashba field. We found a possibility to control the spin precession with magnetic field.