• Journal of the Korean Orthopaedic Association
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• v.56 no.1
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• pp.68-75
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• 2021

Purpose: The purpose of this study was to analyze the motion of the shoulder joint dynamically through a depth sensor-based motion analysis system for the normal group and patients group with shoulder disease and to report the results along with a review of the relevant literature. Materials and Methods: Seventy subjects participated in the study and were categorized as follows: 30 subjects in the normal group and 40 subjects in the group of patients with shoulder disease. The patients with shoulder disease were subdivided into the following four disease groups: adhesive capsulitis, impingement syndrome, rotator cuff tear, and cuff tear arthropathy. Repeating abduction and adduction three times, the angle over time was measured using a depth sensor-based motion analysis system. The maximum abduction angle (θ_max), the maximum abduction angular velocity (ω_max), the maximum adduction angular velocity (ω_min), and the abduction/adduction time ratio (t_abd/t_add) were calculated. The above parameters in the 30 subjects in the normal group and 40 subjects in the patients group were compared. In addition, the 30 subjects in the normal group and each subgroup (10 patients each) according to the four disease groups, giving a total of five groups, were compared. Results: Compared to the normal group, the maximum abduction angle (θ_max), the maximum abduction angular velocity (ω_max), and the maximum adduction angular velocity (ω_min) were lower, and abduction/adduction time ratio (t_abd/t_add) was higher in the patients with shoulder disease. A comparison of the subdivided disease groups revealed a lower maximum abduction angle (θ_max) and the maximum abduction angular velocity (ω_max) in the adhesive capsulitis and cuff tear arthropathy groups than the normal group. In addition, the abduction/adduction time ratio (t_abd/t_add) was higher in the adhesive capsulitis group, rotator cuff tear group, and cuff tear arthropathy group than in the normal group. Conclusion: Through an evaluation of the shoulder joint using the depth sensor-based motion analysis system, it was possible to measure the range of motion, and the dynamic motion parameter, such as angular velocity. These results show that accurate evaluations of the function of the shoulder joint and an in-depth understanding of shoulder diseases are possible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12A
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• pp.1320-1328
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• 2007

In recent year, the popularity of WLAN has generated much interests on improvement and performance analysis of the IEEE 802.11 protocol. In this paper, we analyze two medium access methods of the IEEE 802.11 MAC protocol by investigating the MAC layer packet service times when arrival packet sizes have a general probability distribution. We use the M/G/1/K queueing model to analyze the throughput and the delay performance of IEEE 802.11 MAC protocol in a wireless LAN. We compare the performances of Basic access method and RTS/CTS access method. We take some numerical examples for the system throughput and the queue dynamics including the mean packet delay and packet blocking probability.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.35S no.10
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• pp.94-117
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• 1998

This paper investigates the performance characteristics of the data link layer of the 1996 version of IEC/ISA fieldbus which is developed as internatioal standard of fieldbus. A discrete-event simulation model of the data link layer of IEC/ISA fieldbus is developed. Using the simulation model, this paper identifies the network parameters that influence the performance of prioritys scheme and real-time data transmission, and analyzes the delay performance of IEC/ISA fieldbus with respect to the change of network parameters. The simulation model also integrates continuous-time simulation model of a control system as application process. Using the integrated simulation model, this study investigates the effect of network-induced delay on the performance of control system. Since the simulation model developed in this study can predict the network performance, it will be effectively utilized in the design phase of control and automation systems that adopt the IEC/ISA fieldbus.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.288-289
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• 2000

SBN, BSKNN KNSBN 등의 tungsten-bronze 계열에 속하는 광굴절 결정은 짧은 파장에서 좋은 감광도와 빠른 응답시간을 갖는다. 이중에서도 KNSBN 결정은 큰 크기의 결정 성장 및 도핑이 용이하고 광굴절 결정에서 중요한 특성 중 하나인 열 안정성(thermal stability)이 좋기 때문에 빠른 응답특성이 요구되는 응용분야에서 촉망받는 매질이다. 본 논문에서는 광정보저장, 광정보처리, 광컴퓨터, 광통신과 같은 다양한 분야에서 응용가능성을 가지는 Cu가 0.04wt.%도핑된 5mm$\times$5mm$\times$5mm 크기의 KNSBN 결정을 이용한 광신호의 증폭기술에 대하여 연구하였다. 먼저 Cu-KNSNB 결정의 2광파 결합 특성을 분석하기 위하여, 기록 파장에 따른 지수이득계수의 외부입사각의존성, 최대 지수이득계수를 나타내는 외부입사각에서 입사빔의 세기비에 따른 2광파 결합 이득을 측정하였다. 또한, 632.8nm파장 영역에서 기록 및 삭제시간 상수, 회절 효율의 입사빔 세기비 의존성을 측정하였다. 그리고, 음향-광학 변조기(AOM: acousto-optic modulator)에 의해 진폭 변조된 신호빔을 이용하여 광신호 증폭특성을 분석하고 그 결과를 제시하였다. 이때 두 빔의 입사각은 최대 지수이득계수를 나타내는 입사반각 12$^{\circ}$로 고정하고, 감쇄기를 이용하여 신호빔의 세기를 조절하면서 신호빔의 차동이득을 측정하였다. 투과된 신호빔은 같은 주파수에서 차동 이득(diffrerential gain)을 보였으며, 이는 moving grating과 시간-변조된 신호빔(또는 펌프빔)사이의 새로운 상호작용은 광굴절 결정의 시간 적분 특성에 의한 것이다. (중략) 경우는 상온에서 펌프 펄스의 유지시간이 0.5% 인 경우 레이저가 동작하는 것을 보여주었다. 이는 구조내에서 열전도가 문제가 된다는 것을 의미하는데 위아래가 공기로 둘러 싸여 있어 발생한 열이 가는 유전체 네트웍을 통해서만 전달 될 수 있기 때문이다. (중략)$^4$A$_2$에 의한 nophonon line R$_1$, R$_2$(680.4, 678.5 nm) 및 $^2$T$_1$$\longrightarrow$$^4$A$_2$(655.7, 649.3, 645.2 nm)의 형광방출 스펙트럼을 얻었으며, 형광수명은 0.264 ms로 조사되었다. 제조된 레이저 발진봉은 직경 6.3 m, 길이 45 nm이었다.\pm$0.06kHz Ge $F_4$; -1.84$\pm$0.04kHz$0.04kHz/TEX>0.04kHz 모국어 및 관련 외국어의 음운규칙만 알면 어느 학습대상 외국어에라도 적용할 수 있는 보편성을 지니는 것으로 사료된다.없다. 그렇다면 겹의문사를 [-wh]의리를 지 닌 의문사의 병렬로 분석할 수 없다. 예를 들어 누구누구를 [주구-이-ν가] [누구누구-이- ν가]로부터 생성되었다고 볼 수 없다. 그러므로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다.

• The Journal of Society for e-Business Studies
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• v.17 no.1
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• pp.39-52
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• 2012

The introduction of iPhone was an opportunity to increase of internal smarphone users in 2009 and it exceeded 15 millions at August, 2011. According to report about usage of smartphone users, elderly people aged over 60 was quite low compared to other groups. Moreover these elderly peoples feel lag behind cause of smartphone non-use. Thus, the aim of this research is to improve usability of smartphone for elderly peoples. The performance evaluation program and questionnaire were developed for this purpose and objective data and subjective data were collected through these. 22 elderly peoples participated in our research and we could derived proper level of target. The results of this research will be applied to smartphone or application for elderly. The meaning of this research is reveal the detailed touch target for elderly based on smartphone environment.

• Journal of Sensor Science and Technology
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• v.4 no.3
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• pp.22-29
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• 1995

Lithium ionic solid electrolyte was synthesized at $60^{\circ}C$ in $N_{2}$ ambience by sol-gel method, using tetraethyl orthosilcate, lithium methoxide, zirconium n-propoxide, and tributyle phosphate as precursors. The prepared material was dried and crushed into powder, and it was pressed into disk type samples. These samples were sintered at $900^{\circ}C{\sim}1100^{\circ}C$ for 50 hours. The physical characteristics of the samples were investigated by TG/DTA, SEM, AES and XRD methods. $CO_{2}$ sensor based on lithium ionic solid electrolyte was fabricated and its operational characteristics were measured. The sensing characteristics of the sensor sintered at $1000^{\circ}C$ shows the variation of e.m.f. about $35{\sim}63\;mV/decade$ for the variation of $CO_{2}$ concentration at $200^{\circ}C{\sim}300^{\circ}C$ of operating temperature, and good linearity for $300{\sim}6000\;ppm$.

• Advanced Industrial SCIence
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• v.3 no.3
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• pp.14-19
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• 2024

Currently, micro LEDs (Light Emitting Diode) are attracting attention in the lighting field along with next-generation displays and have advantages such as high luminance, operating speed, energy efficiency, and long-term driving. It is predicted to bring new innovations in smartphones, televisions, and wearable electronic devices. These micro displays are self-luminous displays that emit light by themselves by being implemented as pixels composed of micrometer-sized LED devices. The main manufacturing processes can be divided into crystal growth, patterning and etching, chip separation and transfer, bonding and wiring, panel assembly and encapsulation, inspection, and quality management. Recently, this technology has developed at a rapid pace, and companies are expanding their investments in these fields. According to recent market research results, the micro LED display market is expected to continue to grow, and the main development direction of development can be summarized as manufacturing process improvement, material innovation, and driving technology development. It is believed that commercialization will accelerate through these studies and lead to innovation in the display industry with high performance and various application possibilities.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.11A
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• pp.1661-1671
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• 2000

본 고에서는 한국통신(Korea Telecom) IMT-2000 시험시스템(이하: Trial system 라고 함) 단말기용 전력증폭단으로 적용하기 위한 다단구동증폭기 및 전력증폭기를 GaAs MMIC로 설계 구현하는 기술을 제시하였다. 설계된 구동증폭기는 3단으로구성하여 RF(Radia Frequency) 송신신호(1955$\pm$70MHz)대역에서 2단 (중간단)의 이득 조정범위가 40 dB이상이 될 수 있도록 능동부품인 MESFET를 Cascade 형으로 구성하고 MESFET의 게이트(gate)에 조정전압을 인가하는 증폭기를 설계하여 GaAs MMIC화 1 침(크기4$\times$5 mm)으로 제작하였다. 아울러, 본 논문에서는 제시한 구동증폭기는 동작주파수 대역폭 범위기 3.5배이고 출력전력은 15dBmm 이며, 출력전력이득이 25~27dB이고 반사계수는 -15~20dB이며 이득평탄도 3dB(동작주파수 대역폭내)로써 Trial system용 단말기의 최종단인 전력증폭단의 출력단 특성을 효과적으로 나타내었다. 그리고, 전력 증폭기는 2개의 입력단에서 출력되는 신호를 분배하는 전력분배기와 병렬구조인 4개의 증폭단에서 출력되는 출력신호를 외부에서 접속하는 전력결합기를 접소하여 구성하였으며 RF(Radio Frequency) 주파수(1955 $\pm$70NHz)에서 대역폭을 4배로 설계하여 광대역인 대역폭을 구현하였고 출력전력은 570mW이며, 출력부가효율(PAE; Power Added Efficency)가 -15$\pm$20dB이고, 이득 평탄도(Gain flatness)는 동작주파수 대역내에서 0.5dB이며 입출력 전압정재파비(Input & Output VSWR)가 13이하인 고출력 전력증포기를 GaAs MMIC화 1칩 (크기; 3$\times$4mm)으로 제작하였다.의 다양성이나 편리성으로 변화하는 것이 국적을 바꾸는 것보다 어려운 시 대가 멀지 않은 미래에 도래할 것이다. 신세기 통신 과 SK 텔레콤에는 현재 1,300만명이 넘 는 고객이 있으며. 이들 고객은 어 이상 음성통화 중심의 이동전화 고객이 아니라 신세기 통신과 SK텔레콤이 함께 구축해 나갈 거대란 무선 네트워크 사회에서 정보화 시대를 살아 갈 회원들이다. '컨텐츠의 시대'가 개막되는 것이며, 신세기통신과 SK텔레콤은 선의의 경쟁 과 협력을 통해 이동인터넷 서비스의 컨텐츠를 개발해 나가게 될 것이다. 3배가 높았다. 효소 활성에 필수적인 물의 양에 따른 DIAION WA30의 라세미화 효율에 관하여 실험한 결과, 물의 양이 증가할수록 그 효율은 감소하였다. DIAION WA30을 라세미화 촉매로 사용하여 아이소옥탄 내에서 라세믹 나프록센 2,2,2-트리플로로에틸 씨오에스터의 효소적 DKR 반응을 수행해 보았다. 그 결과 DIAION WA30을 사용하지 않은 경우에 비해 반응 전환율과 생성물의 광학 순도는 급격히 향상되었다. 전통적 광학분할 반응의 최대 50%라는 전환율의 제한이 본 연구에서 찾은 DIAION WA30을 첨가함으로써 성공적으로 극복되었다. 또한 고체 염기촉매인 DIAION WA30의 사용은 라세미화 촉매의 회수 및 재사용이 가능하게 해준다.해준다.다. TN5 세포주를 0.2 L 규모 (1 L spinner flask)oJl에서 세포간의 응집현상 없이 부유배양에 적응,배양시킨 후 세포성장 시기에 따른 발현을 조사한 결과 1 MOI의 감염조건 하에서는 $0.6\times10^6$cell/mL의 early exponential시기의 세포밀도에서 72시간 배양하였을 대 최대 발현양을 나타내었다. 나타내었다. $\beta$4 integrin의 표현이 침투 능력을 높이는 역할을 하나 이때에는 laminin과 같은 리간드와의 특이

• Journal of Sensor Science and Technology
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• v.7 no.2
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• pp.83-89
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• 1998

$TiO_{2-x}$ thin film humidity sensors have been fabricated by sputtering method and their physical and hygroscopic characteristics have been investigated. The sputtering conditions and sintering conditions affect the sensor's sensitivity toward humidity. AES and SEM micrographs were taken for the analysis of crystal structures, surface morphology caused by adsorbed water vapour. $TiO_{2-x}$ humidity sensors showed negative impedance-humidity characteristics and the sensor which was fabricated by experimental condition 2(rf power of 200W) showed higher sensitivity and linearity than others. Then the slope of the sensor was about $0.794\;K{\Omega}/%RH$ and the response time of $TiO_{2-x}$ humidity sensors was about 2 min. for adsorption and about 3 min. for desorption at the operating temperature of $30^{\circ}C$.

• Journal of The Korean Association of Information Education
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• v.17 no.3
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• pp.253-264
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• 2013

We development the service that teacher and parent can control the smart phone of student in school and home, the name is I_smart_keeper. The service is composed of server system, teacher's application, parent's application and student's application. The control of student's phone in school is operated by school timetable and GPS(Global Positioning System) in smart phone. The student's phone is operating one of six policy. The six policy is 'emergency call only', 'specific application only', 'call only', 'call and text only', 'all allowed' and 'all lock'. The teacher can change the current policy with his or her phone, That is a the temporary policy can be applied on a day. In school hours, teacher is able to instruct student using application appropriate to the teaching. If student is leaving school early and located outside school, the service do free the student's phone by GPS of her or his phone. We show the Smart Health Indicator (SHI)that analyse the pattern of student's phone habit and SHI will guide a desirable student's phone habit. In home, parent can control child's phone. The service will help the risk reduction of a robbery case due to keeping student's phone by teacher in class. Currently one elementary school's all student use I_smart_keeper and three elementary school is testing to some class. The teacher's impression was very good and they usually use I_smart_keeper for class in positive light. Survey results for students with higher satisfaction.