• Journal of the Korea Society of Computer and Information
• /
• v.18 no.4
• /
• pp.183-190
• /
• 2013

Many researchers in the 21st century has found that robot education is effective to develop the learners' creativity and problem-solving ability. However, the robot education can only be applied to the students whose computer skills are high. Also it can be taught in the well-prepared computer classroom. Students have to learn machine language to control their robots, and robots are controlled by different types of software. Therefore this study has constructed command-based programming blocks to do a robot programming without computers. It also presents a prototype of the programming process and a technological method to combine the command and the programming blocks. We used the blocks which are similar with something in flow chart: to support intuition, and to help students transfer what they learned. And types of blocks and details are described for the Robot Programing Education. Combination of command blocks is made by RS-485 connection method and, it is designed to intercommunicate with connected blocks. It also presents a prototypes: of the programming process using designed command blocks, and of the possibility of Unplugged Robot Education System.

• Clean Technology
• /
• v.19 no.2
• /
• pp.84-89
• /
• 2013

The running blots between patterns during electroless nickel electroless palladium immersion gold (ENEPIG) surface finish of printed circuit board (PCB) are investigated and a proper solution is presented. Computational chemistry is first employed to understand the process and experiments are then designed to verify the proposed ideas. A $PdCl_2$ activator which has relatively weak chemical bonding to the epoxy resin is introduced to prevent the formation of palladium seeds on the epoxy resin and a couple of operational measures such as increasing HCl concentration and lowering the temperature of Pd activation process are executed to prevent a further hydrolysis of $PdCl_2$ to more stable $Pd(OH)_2$ in aqueous solution. Computational chemistry provides thermodynamic backgrounds for experiments and their results. This combined approach is expected to be very useful in the research of relevant processes.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.117-117
• /
• 2016

일반적인 박막 성장용 CVD는 막 성장 시간이 짧게는 수분에서 수시간 정도 소요하기 때문에 장비에 문제가 발생 할 시 조치를 취하고 다음 현상을 개선하기에 용이 하였다. 그리고 대분분의 장비가 국산화되어 있을 만큼 많은 경험치가 축척되어 있다. 그러나 2, 4 족 화합물 성장용 CVD는 고아학 렌즈 생산용 장비로 국내에서는 아직 생소하고 공정 경험이 없는 새로운 장비이다. 2,4 족 화합물의 특징은 다음과 같다. 2,4 족 화합물은 M, N 이라는 두가 물질이 결합하여 형성한다. 2,4 족 화합물은 높은 융점과 낮은 증기압을 갖니다. 이런 물질들은 고온에서 아래와 같이 평형적으로 반응한다. $$nMN_{(s)}=nM_{(g)}+Nn_{(g)}$$ 화합물인 $MN_{(g)}$의 상태로 존재할 수 있으나 일바적으로 n=2인 4족 원소의 2원자 분자로된 기체가 지배적이다. 증기상을 이용한 성장 공정에서는 구성 원자나 분자를 만들어내는 단계, 이들을 공급원에서 기판까지 수송하는 단계, 기판 위에 흡착하는 단계, 핵의 생성과 단결정을 생성하는 단계, 필요치 않는 구성물을 제거하는 단계를 거쳐 공정이 진행 된다. 각 공정은 성장 물질에 충분한 자유도를 주어야하고 자유도를 주기 위해서는 많은 열에너지가 공급 되어야 한다. 따라서 기존의 박막 성장 공정 보다 성장 속도가 느리고 증착하는 양보다는 버리는 양이 많으며 버려지는 성장물질들은 급격한 온도 변화가 생기는 곳에서 급격히 증착하기 시작한다. 본 성장 공정이 진행되는 압력은 30 torr 부근이며 공정 온도는 $1000^{\circ}C$ 부근이다. 30 torr 영역에서는 열전달이 대기압과 같은 속도로 진행되기 때문에 지속적으로 온도에의해 손상을 받는 부위가 있을 수 있다. 높은 공정 온도와 높은 공정 압력은 내부 구조물로 발생된 열을 빠르게 장비 표면으로 수송하게 되고 그 결과 장비의 연결 부분에 장착된 오링에 손상을 주게 된다. 오링 손상을 방지 하기위해 냉각수 라인을 형성하여 오링을 보호하게 되면 열역학적 기울기가 급격히 발생하는 부분이므로 CVD의 반응 부산물들이 빠른 시간동안 증착하게 되고 막히는 현상이 발생하게 된다. 목표한 두게까지 박막을 성장시키기 위해서는 장시간 공정이 필수이며 장시간 공정을 안정적으로 가져가지 위해서는 배기 라인의 막힘 현상을 해결하여야 한다. 본 논문에서는 막힘 현상의 진행을 시간에 따라 해석하였으며 장시간 공정을 진행하기위해 필요한 요소와 기구적으로 조치가 가능한 방법에 대해 작성하였다.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.25 no.5
• /
• pp.1257-1268
• /
• 2015

Multi-functional devices was originally an equipment performing image processing, but function transmitting image data digitized by combining fax function and function of network are added and it was rapidly developed. Also, functions of internet application, application expansion, remote sharing and image treatment were added to multi-functional devices. But, multi-functional devices can cause security vulnerability such as data exposure, eavesdropping, etc. because of the threatening by network connection. Therefore, common criteria of multi-functional devices are necessary, but there is no protection profile for multi-functional devices now. Therefore, concrete standards of evaluation are not applied to evaluate secure for products, so it was difficult to maintain uniformity of evaluation quality. Therefore, this paper developed protection profile for multi-functional devices based on common criteria of evaluation so as to analyze threats of multi-functional devices and use secure multi-functional devices.

• 한국생물공학회:학술대회논문집
• /
• 2003.04a
• /
• pp.74-78
• /
• 2003

Multi-channel images of 11-MUA and 11-MUOH self-assembled monolayers were obtained by using two-dimensional surface plasmon resonance (SPR) absorption. Patterning process was simplified by exploiting direct photo-oxidation of thiol bonding (photolysis) instead of conventional photolithography. Sharper images were resolved by using a white light source in combination with a narrow bandpass filter in the visible region, minimizing the diffraction patterns on the images. The line profile calibration of the image contrast caused by different resonance conditions at each points on the sensor surface (at a fixed incident angle) enables us to discriminate the monolayer thickness in sub-nanometer scale. Furthermore, there is no signal degradation such as photo bleaching or quenching which are common in the detection methods based on the fluorescence.

• Journal of the Korean School Mathematics Society
• /
• v.10 no.3
• /
• pp.353-367
• /
• 2007

The purpose of this study was to examine what errors students made in solving word problems with figures and to compare the problem-solving abilities of boys and girls for each type of word problems with figures. It's basically meant to provide information on effective teaching-learning methods about world problems with figures that were given the greatest weight among different sorts of word problems. The findings of the study were as fellows: First, there was no difference between the boys and girls in the types of error they made. Both groups made the most errors due to a poor understanding of sentences, and they made the least errors of making the wrong expression. And the students who gave no answers outnumbered those who made errors. Second, as for problem-solving ability, the boys outperformed the girls in problem solving except variable problems. There was the greatest gap between the two in solving combining problems. Third, they made the average or higher achievement in solving the types of problems that were included much in the textbooks, and made the least achievement in relation to the types of problems that were handled least often in the textbooks.

• Polymer(Korea)
• /
• v.30 no.4
• /
• pp.318-325
• /
• 2006

Polypropylene-clay nanocomposites were studied by the modification of clay with amino silanes to introduce covalent bonds in nanocomposites, and prepared by melt-compounding with polypropylene, clay modified with amino silanes and maleic anhydride grafted polypropylene. The . .structure and surface properties of modified clay were determined by x-ray diffraction, infrared spectrum, and solid-state $^{29}Si$ nuclear magnetic resonance spectrum. The modification of clay with aminosilanes led to the increase of the silicate interlayers to about $19.8{\AA}$, the weakening effects of hydroxy group at $3650cm^{-1}$ and the signal of amine groups at -69 ppm proved that the modification had taken place.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.11
• /
• pp.2435-2441
• /
• 2010

A global healthcare system based on M2M technology is proposed to support a good mobility, flexibility and scalability to the patients in 6LoWPAN. Sensor nodes integrated with wearable sensors are linked to gateway with IEEE 802.15.4 protocol and 6LoWPAN protocol for data acquisition and transmission purpose via external network. In the server, heart rate variability signals are obtained by signal processing and used for time and frequency domain performance analysis to evaluate the patient's health status. Our approach for global healthcare system with non-invasive and continuous IP-based communication is managed to process large amount of biomedical signals in the large scale of service range accurately.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.3
• /
• pp.66-72
• /
• 2016

An LED lighting control system was developed to combine information technology and LED lights for efficient management and energy savings. The system can monitor and control the status of an LED luminaire using Bluetooth wireless communication, sensor technology, and smart phones. An LED lighting control circuit was designed using a temperature sensor, illumination sensor, and Bluetooth module with a fuzzy constant-current control circuit. We extended the lifetime and prevented damage to the LED by optimizing the supply current of the LED luminaire based on the heat-generation temperature of $70^{\circ}C$ of an LED heat sink. We also automatically adjusted the ON/OFF time depending on the ambient illumination of the LED luminaire. By allowing easy control of the LED luminaires on a smartphone, we improved the efficiency and achieved energy savings. The control system was validated through experiments for normal operation.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.9
• /
• pp.4186-4192
• /
• 2012

Because wind turbines are larger and more off-shore construction due to economic and environmental factors, it is more difficult to access the wind turbine as well as the necessary parts and the maintenance costs are increasing. So, we need to minimize fault elements and to prevent a secondary accident at failure through monitoring to reduce maintenance costs and to increase reliability of operation. In this paper we have implemented ZigBee based wireless sensor nodes and network for wind turbine condition monitoring using temperature, humidity, voltage, current, wind direction, and wind speed sensors. ZigBee wireless sensor nodes signals are transmitted to a central monitoring system via routers. Also, the sensor signals are collected and processed using LabVIEW program to monitor the wind turbine conveniently. The administrators and users can monitor the condition of wind turbine at remote site in real time over TCP/IP.