• Journal of the Institute of Electronics Engineers of Korea SD
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• v.38 no.10
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• pp.687-698
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• 2001

This paper presents a three dimensional stacked pad area away (PAA) package configuration as an implementation method of radio frequency (RF) circuits. 224MHz RF circuits of intelligence traffic system(ITS) were constructed with the stacked PAA RF pakage configuration. In the process of manufacturing the stacked PAA RF pakage, RF circuits were partitioned to subareas following their function and operating frequency. Each area of circuits separated to each subunits. The operating characteristics of RF PAA package module and the electrical properties of each subunits were examined. The measurement of electrical parameters for solder balls which were interconnects for stacked PAA RF packages showed that the parasitic capacitance and inductance were 30fF and 120pH, respectively, which might be negligible in PAA RF packaging system. HP 4396B network/spectrum analyzer revealed that the amplification gain of a receiver and transmitter at 224 MHz was 22dB and 27dB, respectively. The gain was 3dB lower than designed values. The difference was probably generated from fabrication process of the circuits by employing commercial standard

• Sleep Medicine and Psychophysiology
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• v.5 no.2
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• pp.194-201
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• 1998

Objectives : This study was aimed to investigate the differences in intelligence and neuropsychological test findings between patients with obsessive-compulsive disorder(OCD) and normal controls, and to find out brain functions. Methods : To examine the brain functions, Halsted Reitan neuropsychological test, computerized neuropsychological test, Wechsler Memory scale and K-WAIS were applied. Subjects of this study consisted of 12 patients with OCD and 17 normal controls who were matched for age, handedness and education year. Results : The verbal intelligence of OCD was significantly higher than that of normal controls. But there was no significant difference in total and performance intelligence between groups. The total time of tactual performance test in OCD was significantly delayed than that in normal controls. Also the visual recall of Wechsler memory scale in OCD was more impaired than that in normal controls. Conclusion : These findings support that visual-spatial memory, which is related to basal ganglia, is impaired in OCD.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.10-18
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• 2014

In this paper, we propose a new frequency reconfigurable dual-band antenna. By using an electronically compact eighth-mode substrate-integrated-waveguide(EMSIW) resonator, we have designed a compact antenna, which performs dual-band movement by additionally loading a complementary split ring resonator(CSRR) structure. The EMSIW and CSRR structures are designed to satisfy the bandwidths of 1.575 GHz(GPS) and 2.4 GHz(WLAN), respectively. We load the CSRR with a varactor diode to allow a narrow bandwidth and to enable the resonance frequency to continuously vary from 2.4 GHz to 2.5 GHz. Thus, we realize a channel selection function that is used in the WLAN standards. Irrespective of how a varactor diode moves, the EMSIW independently resonates so that the antenna maintains a fixed frequency of the GPS bandwidth even at different voltages. Consequently, as the DC bias voltage changes from 11.4 V to 30 V, the resonance frequency of the WLAN bandwidth continuously changes between 2.38 GHz and 2.5 GHz, when the DC bias voltage changes from 11.4 V to 30 V. We observe that the simulated and the measured S-parameter values and radiation patterns are in good agreement with each other.

• Annual Conference of KIPS
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• 2001.10a
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• pp.727-730
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• 2001

멀티미디어 환경의 급속한 발전에 의해 영상처리 기술은 인간의 인체와 관련하여 얼굴인식, 제스처 인식에 관한 응용과 더불어 스포츠 관련분야로 깊숙히 정착하고 있다. 그러나 입력영상으로부터 움직이고 있는 선수들의 동작을 추출 및 추적하는 일은 컴퓨터비전 연구의 난 문제 중의 하나로 알려져 있다. 이러한 축구경기의 TV 중계에 있어서 하이라이트 장면의 자동추출(자동색인)은 그 경기의 가장 집약적인 표현이며, 축구경기 전체를 한 눈에 파악할 수 있도록 해주는 요약(summary)이자 intensive actions이고 경기의 진수이다. 따라서 축구경기와 같이 비교적 기 시간(대체로 1시간 30분) 동안 다수의 선수(양 팀 합해서 22명)들이 서로 복잡하게 뒤얽히면서 진행하는 경기의 하이라이트 장면을 효과적으로 포착하여 표현해 줄 수 있다면 TV를 통해서 경기를 관람하는 시청자들에게는 경기의 진행상황을 한 눈에 효과적으로 파악할 수 있게 해주어 흥미진진한 경기관람을 할 수 있게 해주고, 경기의 진행자들(감독, 코치, 선수 등)에게는 고차원적이고 과학적인 정보를 효과적으로 제공함으로써 한층 진보된 경기기법을 개발하고 과학적인 경기전략을 세울 수 있게 해준다. 본 논문은 이상과 같이 팀 스포츠(Team Spots)의 일종인 축구경기 하이라이트 장면의 자동색인을 위해 뉴럴네트워크 기법을 이용하여 그룹 포메이션(Group Formation) 중의 공격패턴 자동분류 기법을 개발하고 이를 검증하였다. 본 연구에서는 축구경기장 내의 빈번하게 변화하는 장면들을 자동으로 분할하여 대표 프레임을 선정하고, 대표 프레임 상에서 선수들의 위치정보와 공의 위치정보 등을 기초로 하여 경기 중에 이루어지는 선수들의 그룹 포메이션을 추적하여 그룹행동(group behavior)을 분석하고, 뉴럴네트워크의 BP(Back-Propagation) 알고리즘을 사용하여 축구경기 공격패턴을 자동으로 인식 및 분류함으로써 축구경기 하이라이트 장면의 자동추출을 위한 기반을 마련하였다. 본 연구의 실험에는 '98 프랑스 월드컵 축구경기의 다양한 공격패턴에 대한 비디오 영상에서 각각 좌측공격 60개, 우측공격 74개, 중앙공격 72개, 코너킥 39개, 프리킥 52개의 총 297개의 데이터를 추출하여 사용하였다. 실험과는 좌측공격 91.7%, 우측공격 100%, 중앙공격 87.5%, 코너킥 97.4%, 프리킥 75%로서 매우 양호한 인식율을 보였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.3
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• pp.471-479
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• 2018

Recently, the spread of smart TV based Android iOS Set Top box has become common. This paper propose a new approach to control the TV using gestures away from the era of controlling the TV using remote control. In this paper, the AdaBoost algorithm is applied to gesture recognition by using a mono camera. First, we use Camshift-based Body tracking and estimation algorithm based on Gaussian background removal for body coordinate extraction. Using global and local feature vectors, we recognized gestures with speed change. By tracking the time interval trajectories of hand and wrist, the AdaBoost algorithm with CART algorithm is used to train and classify gestures. The principal component feature vector with high classification success rate is searched using CART algorithm. As a result, 24 optimal feature vectors were found, which showed lower error rate (3.73%) and higher accuracy rate (95.17%) than the existing algorithm.

• Journal of Korean society of Dental Hygiene
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• v.24 no.4
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• pp.271-280
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• 2024

Objectives: This study aimed to test whether the digital competence of dental hygienists can affect their intraoral scanning potential in terms of scan time and error. Methods: Dental hygienists and dental hygiene students who had never used an intraoral scanner were surveyed to determine their digital competence. Individual data collected using an intraoral scanner was compared with reference data collected using a model scanner to identify scanning errors, and participants' scanning times were measured. Results: A significant decrease in scanning time was observed as the overall level of digital competence increased. The increase in digital skills and digital knowledge led to a decrease in scanning time by 3.73 and 3.98 minutes, respectively. Conclusions: This study found that digital competence was associated with reduced scan times, but less so with scan errors. This may be due to recent advances in scanning software, and future studies may need to develop a digital competence assessment tool that is more appropriate for the dental field.

• Journal of the Korean Society of Clothing and Textiles
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• v.11 no.1
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• pp.11-19
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• 1987

The objectives of this study were: 1. To investigate the relationship between arm movement and clothing pressure in the upper arm and shoulder blade area. 2. To find out the relationship between ease of basic pattern and clothing pressure in the upper arm and shoulder blade area. 3. To study any interaction between arm movement and ease of clothing on the clothing pressure. This study was an experimental research using the measuring devices of clothing pressure. The subjects were the unmarried college women. Arm movements were 3 types($45^{\circ}$, $90^{\circ}$, $135^{\circ}$) to the horizontal direction. The ease of basic pattern in the breast was 3 types(4 cm, 6 cm, 8cm). The statistical analyses used in this study included mean, standard deviation and one-way analysis of variance. The results obtained from this research were as follows; 1. The whole clothing pressure increased as the angle of the arm movement increased. Part of upperarm and shoulder blade above axillar gave high clothing pressure while part of upperarm and shoulder blade above upper breast, low pressure. Difference between highest clothing pressure and lowest clothing pressure increased as the arm movementdid. 2. The whole clothing pressure increased as the ease of the basic pattern in breast decreased. No matter how the ease of basic pattern in the breast area varied, the Points where generally showed high and low pressure were identical. 3. The whole arm pressure increased as the movement angle increased and the ease of pattern in breast area decreased. Difference between highest clothing pressure and lowest clothing pressure increased as the movement angle increased and the ease decreased.

• Aerospace Engineering and Technology
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• v.13 no.1
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• pp.37-43
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• 2014

The ground station which operates the LEO satellite performs monitoring state of health of the satellite, sending the commands for the imaging mission of receiving the images during about 10 minutes of contact time. To finish the planned procedure in limited contact time, specific level of autonomy is applied in the satellite and the ground system. For example, the attitude and orbit control logic has high level of autonomy because it must be operated alone for long period without operator intervention. On the other hand, the fault management logic has relatively low level of autonomy because of that failure detection and safing operation are performed on-board, whereas failure identification and recovery are on-ground operation. The level of autonomy of the satellite affects also the ground operation. The command set for mission operation is generated by ground system. If the satellite has higher level of autonomy, some of operation currently done on-ground can be performed on-board, so the ground operation can be simplified. In this paper, we discuss the level of autonomy and propose a concept for improving the level of autonomy of an LEO satellite.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.299-299
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• 2016

SiC는 넓은 에너지갭 (Eg=~3.4 eV)을 갖는 반도체로써, 고전압, 고온에서 동작이 가능하여 기존의 Si기반의 파워디바이스를 대체하기 위한 물질로 많은 연구가 이루어지고 있다. 파워 디바이스의 성능 향상을 위해서는 기판과 절연체 사이의 계면에 생성되는 계면 결함을 감소시켜야 한다. 따라서 본 연구에서는 SiC 기판에 high-k 물질인 HfO2를 증착하여 HfO2/SiC 계면에 유도된 결함을 분석하고 이를 감소시킬 수 있는 방법에 대한 연구를 수행하였다. HfO2 박막은 atomic-layer-deposition (ALD) 방법을 이용하여 SiC 기판 위에 $200^{\circ}C$에서 증착하였다. HfO2 박막 증착 후 NH3 분위기에서 rapid thermal annealing 방법을 이용하여 $600^{\circ}C$에서 1분 동안 열처리 진행하였다. Current-voltage (I-V) 측정을 통해 열처리 전 HfO2/SiC의 절연파괴 전압이 약 8.3 V 임을 확인하였다. NH3 열처리 후 HfO2/SiC의 절연파괴 전압이 10 V로 증가하였으며 누설 전류가 크게 감소하는 것을 확인하였다. 또한 capacitance-voltage (C-V) 측정을 통해 열처리 후 flat band voltage가 negative 방향에서 positive 방향으로 이동함을 확인하였고, 이를 통해 NH3 열처리 방법이 HfO2/SiC 계면에 존재하는 결함을 감소시킬 수 있음을 확인하였다. 전자 구조상의 conduction band edge에 존재하는 결함 준위를 분석하기 위해 x-ray absorption spectroscopy (XAS) 분석을 실시하였고, 열처리 전 HfO2/SiC 계면에 많은 결함 준위가 존재함을 확인하였으며, x-ray photoelectron spectroscopy (XPS) 분석을 통해 이 결함 준위가 oxygen deficiency state과 관련됨을 알 수 있었다. NH3 열처리 후 결과와 비교해보면, oxygen deficiency state가 감소함을 확인하였으며 이로 인해 conduction band edge에 존재하는 결함 준위가 감소함을 알 수 있었다. 따라서, NH3 열처리 방법을 이용하여 HfO2/SiC 계면에 존재하는 결함을 감소시킬 수 있으며, HfO2/SiC의 물리적, 전기적 특성을 향상시킬 수 있다는 결과를 도출하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1846-1855
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• 2015

In this paper, a precise relative positioning with TD(time differenced) carrier phase measurements from a low-cost GNSS(Global Navigation Satellite System) receiver is proposed and analysed. The proposed method is using carrier phase measurement from a single GNSS receiver that reference receiver is not required and stand alone positioning is possible. TD operation removes the troublesome integer ambiguity resolution problem, and if the time interval is short, other error, such as, ionospheric, tropospheric delay and ephemeris error are effectively eliminated. The error analysis of the proposed method shows that a precise and positioning with carrier phase is possible. The implemented system is evaluated using a real car experiments. The results show that the horizontal positioning error was less than 3m during 10 minutes experiments, which is 4 times more precise than the results of normal code based absolute positioning.