• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.136-137
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• 2008

Solar cell's efficiency depends on silicon's characteristic itself, or additional process such as texturing, coating, etc. Using PC1D, by adjusting Texturing, Base Resistivity, Emitter Doping, simulate many situation and observe the result. When texture Angle=$80^{\circ}$, Texture Depth=2um, Base Resistivity = 0.2, Emitter Doping = 8*Exp(19) are set, the solar cell's efficiency si 19.89%, and optimized.

• Journal of International Academy of Physical Therapy Research
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• v.7 no.2
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• pp.1051-1055
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• 2016

The purpose of this study was to investigate the effect of the screen size of smart devices on the bending angle of the cervical spine. The subjects of this study were 30 healthy adults(15 men and 15 women) who used smartphones and tablet PC(personal computer). The changes in the bending angle of the upper and lower cervical spine were measured in the subjects after they had used a smartphone and a tablet PC for 300 seconds each. To make sure that all subjects began in the same starting position, an angle-measuring instrument was used to set the angles of the ankle, knee, hip, and arm joints to 90 degree. The subjects were asked to keep the trunk straight. They were asked to hold a smartphone in their hand and to bend their neck so that they could look down at the screen. Once they began using the smartphone in this manner, they were free to change their posture. We used a paired t-test to compare the bending angle of the cervical spine on subjects who used smartphones and tablet PC in the long-term and short-term there production error of cervical and the significance level was cervical. The results showed that, when using a smartphone and a tablet PC for 300 seconds, there was no significant difference in the bending angle of the upper cervical spine(p>.05), although there was a significant difference in the bending angle of the lower cervical spine(p<.05).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.6
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• pp.641-646
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• 2004

We report the changes of the microwave reflection coefficients S$_{11}$ of copper(II)-phthalocyanine (CuPc) thin films by using a near-field microwave microscope(NSMM) in order to understand the phase transition of CuPc. For a NSMM system, a high-quality microstrip resonator coupled with a dielectric resonator was used. CuPc thin films were prepared on the pre-heated glass substrates using a thermal evaporation method. The reflection coefficients S$_{11}$ of CuPc thin films were changed by the dependence on the substrate pre-heating temperatures. By comparing reflection coefficient S$_{11}$ and crystal structures, we found the phase transition of CuPc thin films from $\alpha$-phase to $\beta$-phase at the substrate heating temperature 200 $^{\circ}C$./TEX>.

• The Journal of Society for e-Business Studies
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• v.17 no.3
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• pp.117-128
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• 2012

There was a large scale of DDoS(Distributed Denial of Service) attacks mostly targeted at Korean government web sites and cooperations's on March 4, 2010(3.4 DDoS attack) after 7.7 DDoS on July 7, 2009. In these days, anyone can create zombie PCs to attack someone's website with malware development toolkits and farther more improve their knowledge of hacking skills as well as toolkits because it has become easier to obtain these toolkits on line, For that trend, it has been difficult for computer security specialists to counteract DDoS attacks. In this paper, we will introduce an essential control list to prevent malware infection with live forensics techniques after analysis of monitoring network systems and PCs. Hopefully our suggestion of how to coordinate a security monitoring system in this paper will give a good guideline for cooperations who try to build their new systems or to secure their existing systems.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.589-592
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• 2008

Recently, as importance of quality control of the structure has been recognized, non-destructive testing, determining quality of the structure without damage, has been widely applied. However, its application has been primarily focused on laboratory development because variety of parameters in field has been not fully experienced and understood. This study aims to evaluate the field applicability of the ultrasonic testing method for PC beams. Material properties of 18 cylinders, cured in the same field condition, were measured up to 60 days and compared to those of the ultrasonic measurements from 34 PC beams in field before tensioning. Test results indicate that uni-axial strength and elastic modulus of PC beams can be predicted within reasonable range using the ultrasonic technique. However, it is also noted that considerations on field condition is required to increase the reliability of estimation.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.477-480
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• 2008

In tunnel, though the frequency of fire occurrence is relatively lower than other structures, the characteristics of sealed space tends to cause the temperature to rapidly rise to more than $1000^{\circ}C$ within 5 minutes after fire, which might eventually lead to a large fire that usually results in a loss of lives and the damage to the properties, not to mention a huge cost necessary for repair and maintenance after fire. Referring to foreign tunnel fire scenarios, it clarified the heat transfer characteristics of concrete PC panel lining depending on fire intensity (ISO, MHC, RWS), and to identify the range of thermal damage, the evaluation was carried out using ITA standard. As a result, 39mm under ISO fire condition, 50mm under MHC and 100mm under RWS were measured. And when it comes to spalling, 30mm was measured under RWS. When PC panel was designed to serve the support, a fire resistance to the minimum depth of 100mm of the concrete that might be damaged under the fire shall be maintained, and in case of a non-support structure, PC lining shall have at least 100mm thickness.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.95-105
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• 2013

The music education improves the creative talent, social skills and academic achievement of the students. For the efficient music education, it is requested to develop the collaborative educational learning tools, especially electronic collaborators suitable to the leaner's study patterns and speed. In this paper, we propose a new method to develop a PC-based self learning software for the flute performance using templates and descriptors to make the contents form and substance. Our proposed method can allow user to modify the descriptors to match the contents to his level. We implemented a PC-based self learning software for the flute performance compactly and a feasibility test showed the efficiency of our proposed method to construct a self learning tool to play the flute and the tool can be utilized for the beginner to learn playing flute.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.949-964
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• 2012

Our PC have been under constant threat of malicious codes and viruses today. As many new ways of cyber attacks are being developed, such as zero-day-attack, nobody's PC is guaranteed to be safe from the attacks. In case where a user uses the existing verification protocol on a unsecured PC, the user's verification information may well be threatened by sniffing or man-in-the-middle attack. Especially, deadly attacks like memory hacking would give hard time for users to even recognize any symptom of virus infection. Therefore, this paper designs secured QR-Login user verification protocol for smart devices that are ready to communicate with QR-Code and proposes a way to keep critical data safe when using the internet. This way, user would be able to safeguard his/her critical data even when under attack by unknown attacks and safely carry out extremely sensitive task, like financial trading, on the device.

• Journal of the Korea Institute of Military Science and Technology
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• v.9 no.3
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• pp.48-55
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• 2006

This paper describes the antenna based GPS anti-jamming technology called CRPA(Controlled Reception Pattern Antenna), which used $2{\times}2$ array elements. In this system, the main functions are the antenna complex weight control and the GPS digital I/Q VM(Vector Modulator). To update the VM's I/Q complex weights, the PC based DAC(Digital to Analog Converter) module was also used and the two analog output voltages were applied to the $2{\times}2$ array elements to synthesize the null pattern. In the study, we also simulated the $2{\times}2$ GPS array null patterns to compare the null depth with experimental results. The VM was also modified at the frequency of 1.575GHz for the GPS L1 and controlled by the PC based VM software.

• Journal of the Korea Computer Graphics Society
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• v.11 no.3
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• pp.19-22
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• 2005

정보생물학 분야에 있어서 분자 구조를 3차원으로 렌더링하여 보여주는 것은 매우 중요한 작업이다. 특히 분자의 표면 렌더링은 분자의 3차원 구조 분석 등에 중요하게 사용된다. 그러나 분자 표면 렌더링을 수행하기 위해서는 많은 양의 폴리곤이 필요하게 된다. 특히 대장균 바이러스와 같은 분자량이 많은 거대 분자를 자연스럽게 렌더링 하기 위해서는 고가의 그래픽 전용 워크스테이션을 사용해야 한다. 본 논문에서는 저렴한 일반 PC 급 시스템에서도 거대 분자를 무리 없이 렌더링 할 수 있는 효율적인 알고리즘을 제안하였다. 제안하는 알고리즘은 높은 속도와 좋은 화질을 유지할 수 있는 Hybrid Point & Polygon 렌더링 기법이다. 이 알고리즘은 계층적인 자료구조인 옥트리(Octree)를 사용하였으며 최적의 성능을 내기 위하여 GPU가 작업을 처리한다. 제안된 알고리즘의 성능 평가는 일반 PC급에서 수행되었으며 특히 그래픽 카드 2개를 병렬로 연결하여 높은 성능을 낼 수 있는 SLI(Scalable Link Interface) 환경에서 평가를 수행하였다.