• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.360-365
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• 2007

Jakarta Slide는 아파치 프로젝트 중의 하나로 개발된 WebDAV 서버로서 인터넷 통하여 다양한 콘텐츠의 비동기적인 협업 활동을 지원한다. 하지만 WebDAV 프로토콜은 사용자와 그룹을 위한 작업공간을 명시적으로 지원하지 않기 때문에, Jakarta Slide를 통하여 복잡한 협업을 수행하기는 매우 어렵다. CoSlide는 이러한 문제점을 개선하기 위하여 Jakarta Slide를 확장한 협업시스템으로서 다수의 사용자와 그룹을 위한 다양한 작업공간을 제공하여 효과적인 협업 환경을 제공한다. 협업시스템을 통하여 복잡한 협업을 보다 효과적으로 수행하기 위해서는 협업 참여자들 간에 실시간적인 통신이 원활이 이루어져야 할 필요성이 있다. 본 논문은 CoSlide 협업시스템에서 실시간 메시징을 지원하기 위한 CoJBother 메신저 클라이언트의 개발에 대하여 기술한다. 개발된 CoJBother는 협업시스템의 사용자와 그룹을 정의하기 위하여 개발된 Jabber 프로토콜을 사용하며, 또한 이를 지원하기 위하여 개발된 메신저 서버와 함께 동작한다. 사용자는 CoJBother를 통하여 협업시스템의 작업그룹에 참여하는 사용자들을 확인하고 자동적인 그룹채팅 기능을 사용함으로써 그룹 참여자들과 협업 수행을 위한 원활한 의사소통을 할 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.208-212
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• 2008

인터넷이 발달함에 따라 인터넷 기반의 협업시스템을 이용하여 정보를 교환하고 협업을 수행하는 사용 자와 그룹이 급속히 증가하고 있다. 이러한 사용자들이 급속히 증가함에 따라 사용자들의 다양한 작업 환 경을 고려한 개인화된 협업서비스가 제공되는 것이 바람직하지만 현재의 협업시스템들은 이러한 서비스를 제공하지 않아서 효과적인 협업 환경을 제공하기 어렵다. 본 논문은 협업시스템을 이용하여 다양한 사용자들의 협업 수행을 지원하는 CoPortlet의 개발에 대하여 기술한다. CoPortlet 은 포탈에 포함되는 포틀릿 컴포넌트로서 협업시스템 서버에서 제공하는 다양한 가상 공간을 지원하며, 각 가상공간의 자원을 제어하는 기능들을 제공한다. CoPortlet은 Struts 프레임워크를 바탕으로 설계하였으며, WebDAV 프로토콜을 이용하여 협업시스템과 상호 동작한다. 사용자는 여러 포틀릿과 함께 CoPortlet으로 구성되는 포탈을 이용하여 자신의 작업 환경을 고려한 맞춤형 인터페이스를 구성하고 효과적으로 협업을 수행할 수 있다.

• Journal of the Optical Society of Korea
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• v.16 no.1
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• pp.22-28
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• 2012

We report a focal-length tunable liquid lens based on thermopneumatically driven fluidic pressure. The fluidic pressure is generated by deformation of an elastomeric diaphragm induced by thermopneumaticity from a laterally integrated microheater sealed within an air chamber. The pressure is transmitted by a confined liquid to a lens diaphragm through an internal fluid channel. The liquid filling under the lens diaphragm functions as a liquid lens for dynamic focusing with properties depending on the curvature of the deformed diaphragm. The diaphragm area of the air chamber is designed five times larger than that of the lens cavity to yield high focal-length tunability by amplified deflection of the lens diaphragm. With our method, we achieved excellent focal-length tunability from infinity (without an input current) to 4 mm (with an input current of 12 mA) with a lens aperture diameter of 2 mm.

• The Journal of Korean Academy of Prosthodontics
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• v.42 no.3
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• pp.294-300
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• 2004

The present experimental study was designed to address two issues. The first was to investigate whether oxidation voltage of titanium implants influenced bone tissue responses after an in vivo implantation. The second aim was to investigate secondary stability change after 1 to 3months period. Screw-shaped implants with a wide range of oxide properties were prepared by electrochemical oxidation methods, where the oxide thickness varied in the range of $3-15{\mu}m$. The micro structure revealed pore sizes of $1-3{\mu}m$, the crystal structures of the titanium oxide were amorphous, anatase and a mixture of anatase and rutile type. Bone tissue responses were evaluated by resonance frequency measurements that were undertaken 1 to 3months after insertion in the rabbit tibia. It was concluded that no statistical difference of RFA values was found between the groups, RFA gains after Imonth and 3months were calculated.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.2
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• pp.53-62
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• 2018

This study propose a new approach to control the optimal working path of vertical type articulated robot with translation joint for trimming working process automation in forging manufacturing process. The basic structure of the proposed robotic joints controller consists of a Proportional-Intergral controller and a Proportional-Derivative controller in parallel. The proposed control scheme takes advantage of the properties of the fuzzy PID controllers. The proposed method is suitable to control of the trajectory and path control in cartesian space for vertical type articulated robot manipulator. The results illustrates that the proposed fuzzy computed torque controller is more stable and robust than the conventional computed torque controller. The reliability is varified by simulation test for vertical type s articulated robot with seven joints including one trqanslation joint.

• Journal of Sensor Science and Technology
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• v.20 no.6
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• pp.368-374
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• 2011

A microfluidic device for real-time monitoring of residual free chlorine and pH in water based on optical absorption is proposed. The device consists of a serpentine micromixer for mixing samples with a reagent, and a photodiode and light emitting diode(LED) for the detection of light absorbance at specific wavelengths, determined for specific reagent combinations. Spectral analyses of the samples mixed with N, N'-diethyl-p-phenylenediamine(DPD) reagent for chlorine determination and bromothymol blue(BTB) for pH measurement are performed, and the wavelengths providing the most useful linear changes in absorbance with chlorine concentration and pH are determined and used to select the combination of LED and photodiode wavelengths for each analyte. In tests using standard solutions, the device is shown to give highly reproducible results, demonstrating the feasibility of the device for the inexpensive and continuous monitoring of water quality parameters with very low reagent consumption.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.288-293
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• 2003

In this paper, Filter could use to IMT2000 repeater using resonator of Comb-line form that has waveguide structure and designed. Coupled resonators designed using slot in wall between resonators to compact. 5-stage resonators have equal structure and input and output part was optimized to get into minimum impedance. Band pass filter characteristic satisfied design condition as result that used Chebyshev function that have 0.2 dB ripple and analyze using simulation tool.

• Transactions of the Korean hydrogen and new energy society
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• v.21 no.1
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• pp.35-41
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• 2010

Water management is an important issue of PEM fuel cell operation. Water is the product of the electrochemical reactions inside fuel cell. If liquid water accumulation becomes excessive in a fuel cell, water columns will clog the gas flow channel. This condition is referred to as flooding. A number of researchers have examined the water removal methods in order to improve the performance. In this paper, a new water removal method that investigates the use of vibro-acoutic methods is presented. Piezo-actuators which are devices to generate the flexural wave are attached at the end of a cathode bipolar plate. Flexural wave is used to impart energy to resting droplets and thus cause movement of the droplets in the direction of the traveling wave.

• Archives of Plastic Surgery
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• v.40 no.1
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• pp.57-61
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• 2013

Background Von Recklinghausen disease or neurofibromatosis type 1 is an autosomal dominant genetic disorder of chromosome 17q11.2. The most common characteristic findings of NF 1 include multiple and recurrent cutaneous neurofibromas associated with psychosocial distress. Methods Sixteen patients (9 female, 7 male; average age, 31 years; range, 16 to 67 years) with multiple cutaneous neurofibromas between March 2010 and February 2012 were included in the study. All patients were treated with radiosurgical ablation and excision under general anesthesia. Results All 16 patients were satisfied with the results, when questioned directly during the outpatient department follow-up. The only complaint from a few patients was minimal scarring, but acceptable results were obtained in the end. Conclusions The radiofrequency procedure is almost bloodless and quick, creating a smaller necrotizing zone. Therefore, instead of employing the time consuming traditional surgery, such as laser therapy and electrosurgical excision, that produces uncertain results and can affect normal adjacent tissue, treatment of neurofibromas with radiofrequency ablation and excision can be an alternative choice of treatment for patients with a large number of neurofibromas.

• Journal of the Korean Society of Visualization
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• v.11 no.1
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• pp.28-33
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• 2013

This paper describes aerodynamic characteristics of an Archimedes spiral wind turbine with various angles of attack. The range of angles was controlled from $-30^{\circ}$ (clockwise) to $+30^{\circ}$ (clockwise). The rotating speed of wind turbine at the same angle of attack in both directions was different. The reason why the-maximum rotational speed was observed at $15^{\circ}$ in clockwise direction can be explained based on angular momentum conservation. Quantitative flow visualization around Archimedes wind turbine blade was carried out between $-15^{\circ}$ (clockwise) and $+15^{\circ}$ (counter clockwise) using high resolution PIV method. The relationship between drag force and rotating speeds was discussed. From these results, optimum design on yawing system of Archimedes spiral wind turbine may provide high efficiency on small wind power system.