• 한국멀티미디어학회논문지
• /
• 제13권8호
• /
• pp.1163-1170
• /
• 2010

본 논문에서는 인터넷을 이용한 원격지 공정관리 시스템을 개발하는데 있어서 유지보수가 용이하고, 기능의 추가가 쉽도록 자바 언어와 GoF 디자인 패턴을 이용한 설계기법을 보인다. 시스템의 구현을 위해 현재 운전되고 있는 설비들의 상태를 파악할 수 있도록 설비 제어 박스에 있는 PLC에 RS232C와 RS422/RS485 통신모듈을 추가하였고, PLC를 통하여 제어되고 있는 정보를 송수신하기 위해 RS232C 통신을 Ethernet으로 변환시켜주는 변환기를 설치하였다. 다계층으로 구성된 시스템을 구현하기 위해 Swing 컴포넌트를 사용하였으며, Applet과 Frame GUI를 동시에 지원하여, 관리자가 인터넷을 통하여 원격지의 작업공정 진도를 쉽게 파악할 수 있도록 하였다. 다계층 구조의 주요 목적은 클라이언트들 간의 자원을 공유하는 것이다. 제안된 시스템은 원격지에서 설비를 제어하기 위한 소프트웨어를 제작하는데 도움을 줄 수 있고, 이와 비슷한 소프트웨어를 제작하려는 개발자에게 기존 코드를 쉽게 재사용하여, 새로운 기능을 쉽게 추가할 수 있다는 장점이 있다.

• Current Optics and Photonics
• /
• 제7권2호
• /
• pp.119-126
• /
• 2023

The vibratory and rotational levels of many biological macromolecules lie in the terahertz (THz) band, which means that THz techniques can be used to identify and detect them. Moreover, since the biological activity of most biomolecules only becomes apparent in aqueous solution, we use microfluidic technology to study the biological properties of these biomolecules. THz time-domain spectroscopy was used to study the THz absorption characteristics of graphene oxide (GO) aqueous solution at different concentrations and different exposure times in fixed electric or magnetic fields. The results show that the spectral characteristics of the GO solution varied with the concentration: as the concentration increased, the THz absorption decreased. The results also show that after placing the solution in an external electric field, the absorption of THz first increased and then decreased. When the solution was placed in a magnetic field, the THz absorption increased with the increase in standing time. In this paper, these results are explained based on considerations of what is occurring at the molecular scale. The results of this study provide technical support for the further study of GO and will assist with its improved application in various fields.

• 마이크로전자및패키징학회지
• /
• 제26권3호
• /
• pp.81-88
• /
• 2019

본 연구에서는 그래핀 산화(graphene oxide, GO) 분말 첨가가 ball grid array(BGA) 패키지와 printed circuit board(PCB)간 Sn-3.0Ag-0.5Cu(SAC305) 무연솔더 접합부의 electromigration(EM) 수명에 미치는 영향에 대하여 보고 하였다. 솔더 접합 직후, Ni/Au표면처리된 패키지 접합계면에서는 $(Cu,Ni)_6Sn_5$가 생성되었으며 organic solderability preservative(OSP) 표면처리 된 PCB 접합계면에서는 $Cu_6Sn_5$ 금속간화합물(intermetallic compound, IMC)이 생성되었다. $130^{\circ}C$, $1.0{\times}10^3A/cm^2$ 전류밀도 하에서 EM 수명평가 결과, GO를 첨가하지 않은 솔더 접합부의 평균 파괴 시간은 189.9 hrs으로 도출되었고, GO를 첨가한 솔더 접합부의 평균 파괴 시간은 367.1 hrs으로 도출되었다. EM에 의한 손상은 패키지 접합계면에 비하여 pad 직경이 작은 PCB 접합계면에서 전자 유입에 의한 Cu의 소모로 인하여 발생하였다. 한편, 첨가된 GO는 하부계면의 $Cu_6Sn_5$ IMC와 솔더 사이에 분포하는 것을 확인하였다. 따라서, SAC305 무연솔더에 첨가된 GO가 전류 집중 영역에서 Cu의 빠른 확산을 억제하여 우수한 EM 신뢰성을 갖는 것으로 생각된다.

• International Journal of Aeronautical and Space Sciences
• /
• 제8권1호
• /
• pp.46-53
• /
• 2007

In this paper, a guidance law for vision-based automatic landing of unmanned aerial vehicles (UAVs) is proposed. Automatic landing is a challenging but crucial capability for UAVs to achieve a fully autonomous flight. In an autonomous landing maneuver of UAVs, the decision of where to landing and the generation of guidance command to achieve a successful landing are very significant problem. This paper is focused on the design of guidance law applicable to automatic landing problem of fixed-wing UAV and rotary-wing UAV, simultaneously. The proposed guidance law generates acceleration command as a control input which derived from a specified time-to-go ($t_go$) polynomial function. The coefficient of $t_go$-polynomial function are determined to satisfy some terminal constraints. Nonlinear simulation results using a fixed-wing and rotary-wing UAV models are presented.

• 동의생리병리학회지
• /
• 제16권5호
• /
• pp.1016-1019
• /
• 2002

To examine the cytotoxic effect of glucose oxidase(GO) in cultured mouse cerebral neurons, cytotoxicity was measured by MTT assay after cultured nerve cells were incubated for 3 hours in the media containing 1 ～ 60mU/ml concentrations of GO. In addition, the neuroprotective effect of Ramulus et uncus uncariae(REUU) was determined by MTT assay in these cultrures. Cell viability was remarkably decreased in a dose- and time-dependent manner after cultured mouse cerebral neurons were exposed to 30mU/ml GO for 3 hours. In the neuroprotective effect of REUU on GO-induced toxicity, REUU blocked the GO-mediated neurotoxicity in these cultures. From above the results, it suggests that GO is toxic in cultured mouse cerebral neurons and selective herb extract such as REUU is effective in prevetion of the neurotoxicity induced by GO.

• Corrosion Science and Technology
• /
• 제15권2호
• /
• pp.92-107
• /
• 2016

Graphene was coated on austenitic and martensitic stainless steels to simulate the metallic bipolar plate of proton exchange membrane fuel cell (PEMFC). Graphene oxide (GO) was synthesized and was reduced to reduced graphene oxide (rGO) via a hydrazine process. rGO was confirmed by FE-SEM, Raman spectroscopy and XPS. Interfacial contact resistance (ICR) between the bipolar plate and the gas diffusion layer (GDL) was measured to confirm the electrical conductivity. Both ICR and corrosion current density decreased on graphene coated stainless steels. Corrosion resistance was also improved with immersion time in cathodic environments and satisfied the criteria of the Department of Energy (DOE), USA. The total concentrations of metal ions dissolved from graphene coated stainless steels were reduced. Furthermore hydrophobicity was improved by increasing the contact angle.

• 전기의세계
• /
• 제29권1호
• /
• pp.21-27
• /
• 1980

The effect of electric shock on human body is enormousness, which leads to warmth, tingling, and even death. The mean values of perception currents obtained on 91 men and 39 women are about 0.77(mA) for men and 0.57(mA) for women. The mean value for women is approximately seven tenths that of men. An individual can tolerate, with no adverse effects, repeated exposure to the reactions associated with currents of his let-go level, and the mean value of let-go currents obtained from 27 normal men is 6.29(mA). Lethal currents flowing human body is very dangerous even for a short time. So, it is necessary to have recourse to animal experiments ot determine lethal current for human. An analysis of experimental data indicates that body weight and shock duration are important factors in determining the lethal current. It is suggested that the relationship between current and shock duration is given by I=K/.root.T, and lethal current is proportional to body weight, where I is the current in milliampere, and T is the time in seconds.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
• /
• pp.375.1-375.1
• /
• 2016

Polymerase chain reaction (PCR) has revolutionized genetics and become one of the most popular techniques in modern biological and medical sciences. It can be used not only as an in vitro DNA amplification method but also used in many bioassay applications. The PCR can be used to exponentially produce a large number of DNA copies from a small quantity of DNA molecules in a few hours. However, as unwanted DNA fragments are also often manufactured, the amplification efficiency of PCR is decreased. To overcome this limitation, several nanomaterials have been employed to increase the specificity of the PCR reaction. Recently, graphene has attracted a great interest for its excellent electron transfer, thermal and biocompatibility. Especially, gold nanoparticle-coated graphene oxide (GO/AuNPs) led to enhance electron and thermal transfer rate and low-charge transfer resistance. Therefore, we report the development of a demonstration for the PCR efficiency using a large-scale production of the GO and combination of gold nanoparticles. Because a thermal conductivity is an important factor for improving the PCR efficiency in different DNA polymerases and different size samples. When PCR use GO/AuNPs, the result of transmission electron microscopy and real-time quantitative PCR (qPCR) showed an enhanced PCR efficiency. We have demonstrated that GO/AuNPs would be simply outperformed for enhancing the specificity and efficiency of DNA amplification procedure.

• Journal of Mechanical Science and Technology
• /
• 제19권4호
• /
• pp.993-1000
• /
• 2005

A vehicle cruise control strategy designed based on human drivers driving characteristics has been investigated. Human drivers driving patterns have been investigated using vehicle driving test data obtained from 125 participants. The control algorithm has been designed to incorporate the driving characteristics of the human drivers and to achieve natural vehicle behavior of the controlled vehicle that would feel comfortable to the human driver. Vehicle following charac­teristics of the cruise controlled vehicle have been investigated using real-world vehicle driving test data and a validated simulation package.

• 건축역사연구
• /
• 제14권1호
• /
• pp.71-87
• /
• 2005

4 royal palaces are currently remained from capital city (Seoul) of 'Cho-Sun(朝鮮)' period. In these palaces, 'Main hall of Royal Palace(正殿)' is the center of the Royal Palaces. The 'Main hall of Royal Palace' of the Royal Palace was the best building of that time. Therefore there were many studies about the 'Main hall of Royal Palace'. But these studies were individual studies of these 'Main hall of Royal Palace'. Therefore, this study is to analyze and compare 4 'Main hall of Royal Palace' of the Royal palaces. It is to study the proportion regarding the Diameter of the pillar, the Height, the pillar and pillar Interval's Distance, and the arrangement of 'Kong-Po(bracket sets)'. With these studies, it is to prove that the 'Main hall of Royal Palace' is the building which high construction technique of this time is expressed. Result of this study is as followings; First, the proportion of pillar height(H) to its diameter(D) average from H=8.0 to 8.5D. Only the Myeong-Jeong-Jeon omitted the 'Go-Ju(高柱)' in the 'Toi-Kan (退間)' to place Ea-Jwa(御座). Second, Second, the proportion of diameter of the pillar of 'Eoi-Bu-Pyeong-Ju(外部平柱)' and 'Nae-Jin-Go-Ju(內陣高柱)' average D1(Diameter of 'Eoi-Bu-Pyeong-Ju') =0.91D2 (Diameter of 'Nae-Jin-Go-Ju'). In regards to the height, the single floor 'Main hall of Royal Palace' and double floor 'Main hall of Royal Palace' seems to be different. The height proportion of the double floor 'Main hall of royal palace' is H1(Height of 'Eoi-Bu-Pyeong-Ju')=0.34H2(Height of 'Nae-Jin-Go-Ju') and single floor 'Main hall of Royal Palace' has a proportion of H1=0.62H2. Third, in Geun-Jeong-Jeon, with the proportion of height and diameter of the pillar, interval's distance between pillars and diameter, the pillar interval distance and height, of 'Ea-kan(御間)' from the 'Toi-Kan' is different from 'Main hall of Royal Palace'. This is because the structure of 'Toi-Kan' of Geun-Jeong-Jeon is not stable. In order to reinforce this, 'Gui-Go-Ju(隅高柱)' of the Geun-Jeong-Jeon jut out $4{\sim}7%$ more compared to In-Jeong-Jeon. Fourth, when comparing double floor 'Main hall of royal palace' of Geun-Jeong-Jeon and In-Jeong-Jeon, based on distance of 'Eoi-Bu-Pyeong-Ju' and 'Nae-Jin-Go-Ju' of lower level, the 'Sang-Bu-Pyeong-Ju(上部平柱)' of Geun-Jeong-Jeon jut out $4{\sim}7%$ more compared to the In-Jeong-Jeon and also It becomes thicker. Fifth, the arrangement of 'Kong-Po' on the front row of 'Gan(間)' had to do with the change of side 'Gan'. Even though the Geun-Jeong-Jeon and the In-Jeong-Jeon were double floors, the arrangement of the 'Kong-Po' is different because the number of side bay is different.