• 구강회복응용과학지
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• 제31권4호
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• pp.310-315
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• 2015

목적: 본 연구는 토크 게이지를 이용하여, 치과 기공사들이 임플란트 기공을 진행할 때 가하는 토크의 양을 측정해 분석하고, 이러한 결과가 보철물에 어떠한 결과를 미치는 알아보기 위함이다. 연구 재료 및 방법: 치과 기공사들이 임플란트 기공시 임플란트 나사에 가하는 토크를 디지털 토크 게이지를 이용하여 측정한다. 이후 기성지대주와 analog를 이용하여, 제조사의 권장 토크로 조였을 때의 길이를 통계학적으로 비교 분석하였다. 결과: 치과 기공사들의 임플란트 기공시 평균 토크는 $1.563{\pm}0.332Ncm$로 나타났으며, 제조사의 권장토크 값으로 조였을 때와 비교하면, 외부연결형의 침하량 차이는 없으나, 내부연결형의 침하량의 차이는 통계적으로 유의한 차이를 보였다(P < 0.05). 결론: 치과기공실에서도 제조사의 권장토크를 이용하여 보철물 기공작업을 시행하고, 정확한 토크 게이지의 사용법을 익히면, 기공오차에 따른 임플란트의 부적합을 어느 정도 해소할 수 있을 것이라 사료된다.

• Carbon letters
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• 제25권
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• pp.1-13
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• 2018

Gold functionalized graphene oxide (GOAu) nanoparticles were reinforced in acrylonitrile-butadiene rubbers (NBR) via solution and melt mixing methods. The synthesized NBR-GOAu nanocomposites have shown significant improvements in their rate of curing, mechanical strength, thermal stability and electrical properties. The homogeneous dispersion of GOAu nanoparticles in NBR has been considered responsible for the enhanced thermal conductivity, thermal stability, and mechanical properties of NBR nanocomposites. In addition, the NBR-GOAu nanocomposites were able to show a decreasing trend in their dielectric constant (${\varepsilon}^{\prime}$) and electrical resistance on straining within a range of 10-70%. The decreasing trend in ${\varepsilon}^{\prime}$ is attributed to the decrease in electrode and interfacial polarization on straining the nanocomposites. The decreasing trend in electrical resistance in the nanocomposites is likely due to the attachment of Au nanoparticles to the surface of GO sheets which act as electrical interconnects. The Au nanoparticles have been proposed to function as ball rollers in-between GO nanosheets to improve their sliding on each other and to improve contacts with neighboring GO nanosheets, especially on straining the nanocomposites. The NBR-GOAu nanocomposites have exhibited piezoelectric gauge factor (${GF_{\varepsilon}}^{\prime}$) of ~0.5, and piezo-resistive gauge factor ($GF_R$) of ~0.9 which clearly indicated that GOAu reinforced NBR nanocomposites are potentially useful in fabrication of structural, high temperature responsive, and stretchable strain-sensitive sensors.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.578-583
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• 2017

본 논문은 최근에 모바일 기기에 적용되고 있는 차세대 터치 기술로서 압력터치 센서를 이용한 3D 터치패드 기술에 관한 것이다. 3D터치 기술은 터치 위치 및 터치 압력을 동시에 검출할 수 있고 멀티터치 기능이 있어야 한다. 본 논문의 목적은 스트레인 게이지를 이용하여 압력터치 센서를 제작하고 2점을 동시에 터치 가능한 압력터치 패드 제작이다. 하드웨어 부분은 터치 인식 센서에 금속 박막형 스트레인 게이지를 이용하였고 각 스트레인 게이지 센서마다 휘스톤 브리지 회로로 미세한 터치 신호를 검출하였다. 또한, 터치 신호 증폭기를 사용하여 터치 신호를 증폭하고 마이크로프로세서를 통해 디지털 데이터로 변환하여 화면에 디스플레이하는 터치 인식 시스템을 만들었다. 소프트웨어 부분은 2점 동시터치가 가능하고 터치 압력에 따라 구별 가능한 터치 인식 알고리즘을 C언어로 제작하였다. 터치 강도와 터치 위치가 다른 두 개의 터치 신호를 동시에 검출하여 화면에 나타내는 실험을 성공적으로 수행하였다. 본 연구를 통해 스트레인 게이지를 이용한 터치 인식 방법으로 3D 터치패드의 응용 가능성을 확인하였다.

• 대한임베디드공학회논문지
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• 제8권2호
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• pp.79-85
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• 2013

This paper proposes a system that utilizes USN(Ubiquitous Sensor Network), Bluetooth and smart phone to improve the function of senior houses. In typical approach, a system in a senior house either directly accesses the status of elderly people by its sensor or is alerted by elderly people who trigger an emergency bell, derive a decision and take an appropriate action. In addition, it is possible for a designated social worker to check the status of senior patients through monitoring system connected by UTP(Unshielded Uwisted Pair) cables, but the responsible person has to be present to monitor patients' status. However, the new system, suggested in this paper, embed Bluetooth function in a blood pressure gauge, thus the smart phone receives patients' health information such as blood pressure through Bluebooth, if any abnormal event occurs. Consequently, the smart phone sends SMS(Short Message Service) to a responsible social worker or a designated hospital. When this program in the paper becomes a reality, an unmanned system that is able to determine suitable actions for certain events will be established, even if a social worker were absence.

• 국제물리치료학회지
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• 제2권2호
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• pp.308-317
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• 2011

The purpose of this study was to investigate the influence of handicraft activities on hand promptness and grasp in the elderly. Subjects were comprised of 14 senior citizens between the ages of 70-85, with 7 subjects in the experiment group and 7 in the control group. Subjects in the experiment group practiced various handicrafts twice a day, while those in the control group did not participate in any special activity. The Jebsen Taylor Hand Function Test was used to evaluate the results, while a dynamometer and pinch gauge were used to measure hand promptness and grasp. The 7 senior citizens in the experiment group were able to increase their hand promptness and grasping skills. Conclusively, handicrafts can help improve hand promptness and grasp in the elderly. Furthermore, the development and improvement of such skills can have a positive influence on the daily lives of senior citizens. Such skills are expected to improve the overall neuro-function in the elderly population.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2010년도 추계학술대회
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• pp.641-642
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• 2010

삼각함수는 직각삼각형에서 한 각의 크기가 일정하면, 이들 변의 비의 값은 삼각형의 크기에는 관계없이 일정하다는 가장 단순하고 독특한 성질에 기초를 둔 학문이다. 직삼각형의 밑변의 길이와 건물을 올려다본 각이 있다면 건물의 높이를 삼각함수를 이용하여 구할 수 있다. 이는 차를 타고 이동하면서 건물의 높이를 가늠할 수 있는 좋은 방법이라고 볼 수 있다.

• Journal of Positioning, Navigation, and Timing
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• 제7권3호
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• pp.165-173
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• 2018

Underwater vehicles use Inertial Navigation System (INS) with high-performance Inertial Measurement Unit (IMU) for high precision navigation. However, when underwater navigation is performed for a long time, the INS error gradually diverges, therefore, an integrated navigation method using auxiliary sensors is used to solve this problem. In terms of underwater vehicles, the vertical axis error is primarily compensated through Vertical Channel Damping (VCD) using a depth gauge, and an integrated navigation filter can be designed to perform horizontal axis error and sensor error correction using a speedometer such as Electromagnetic-Log (EM-Log). However, since EM-Log outputs the forward direction relative speed of the vehicle with respect to the sea and sea current, INS correction filter using this may cause a rather large error. Although it is possible to design proper filters if the exact model of the sea current is known, it is impossible to know the accurate model in reality. Therefore, this study proposes an INS/EM-Log integrated navigation filter with the function to estimate sea current using an Interacting Multiple Model (IMM) filters, and the performance of this filter is analyzed through a simulation performed in various environments.

• 충청수학회지
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• 제26권4호
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• pp.879-885
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• 2013

In this paper, we de ne an extension $f^*:[a,b]{\rightarrow}\mathbb{R}$ of function $f^*:[a,b]_{\mathbb{T}}{\rightarrow}\mathbb{R}$ for a time scale ${\mathbb{T}}$ and prove the convergence theorems for the Henstock delta integral on time scales.

• 충청수학회지
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• 제27권1호
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• pp.113-121
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• 2014

In this paper, we define an extension $f^*:[a,\;b]{\rightarrow}\mathbb{R}$ of a function $f:[a,\;b]_{\mathbb{T}}{\rightarrow}\mathbb{R}$ for a time scale $\mathbb{T}$ and show that f is McShane delta integrable on $[a,\;b]_{\mathbb{T}}$ if and only if $f^*$ is McShane integrable on [a, b].

• 한국해양공학회지
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• 제17권6호
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• pp.1-6
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• 2003

Wave energy dissipation and energy transfer between wave components, during the directional wave breakings, are investigated. Directional incipient and plunging breakers were generated by focusing the multi-frequency and multi-directional wave components at a designed location, based on a constant wave amplitude and a constant wave steepness frequency spectrum. The time series of surface wave elevation was measured at 9 different locations around the wave focusing point, using a wave gauge array. In order to examine the variation of the directional spreading function, the horizontal velocity of fluid motion was also measured. By comparing energy spectrums, before and after the breaking, the characteristics of energy dissipation and energy transfer, caused by wave breaking, are investigated. Their dependencies on directionality, as well as frequency, are analyzed. The breakings significantly dissipate wave energy, through energy transfer, in the upper region of the peak-frequency band, while enhancing wave energy in the low-frequency band.