• Journal of Positioning, Navigation, and Timing
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• 제7권2호
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• pp.61-71
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• 2018

Existing radio positioning systems have a drawback that the attitude of user's tag is difficult to be determined. Although forward link angle of arrival (FLAOA) technology that uses measurements of array antenna arranged in a tag among the angle of arrival (AOA) technologies can estimate attitude and positioning of tags, it cannot extend the estimated results into three-dimensional (3D) results due to complex non-linear model displayed because of the effects of 3D positioning and attitude in tags. This paper proposed a radio navigation technique that determines 3D attitude and positioning via FLAOA / time of arrival (TOA) integration. According to the order of determining attitude and positioning, two integration techniques were proposed. To analyze the performance of the proposed technique, MATLAB-based simulations were used to verify the performance. The simulation results showed that the first proposed method, TOA-FLAOA integrated technique, showed about 0.15 m of positioning error, and $2-3^{\circ}$ of attitude error performances regardless of the positioning space size whereas the second method, differenced FLAOA-TOA integrated technique, revealed a problem that a positioning error became larger as the size of the positioning space became larger.

• 대한감각통합치료학회지
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• 제19권2호
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• pp.12-25
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• 2021

목적 : 감각통합기반의 가족중심코칭이 자폐스펙트럼장애(Autism Spectrum Disorder; ASD)아동의 작업수행도와 만족도에 미치는 효과를 알아보고자 하였다. 연구방법 : 2020년 4월 16일~ 2020년 8월 6일까지 기준에 부합하는 3-6세 ASD 아동 10명과 보호자 10명이 참여하였다. 캐나다 작업수행 평가(Canadian Occupational Performance Measure; COPM)로 아동의 작업 수행도와 만족도를 평가하였고, 목표성취척도(Goal Attainment Scaling; GAS)로 아동의 작업수행을 평가하였다. 실험군은 기존에 받고 있는 감각통합치료와 함께 주 1회 60분, 4주간 가정방문 및 영상통화로 시행되는 목표활동에 대한 개별화된 가족중심코칭을 받았다. 통제군은 기존에 받고있는 감각통합치료와 함께 목표활동에 대한 감각통합기반의 일반적인 상담으로 진행하였다. 중재 전과 후의 집단별 COPM의 수행도와 만족도, GAS 점수 변화를 비교하기 위해 Wilcoxon 부호 순위 검정을 사용하였고, 중재 전후 집단 간의 COPM의 수행도와 만족도, GAS의 점수의 차이를 비교하기 위해 Mann-Whitney U 검정을 사용하였다. 두 집단 간의 효과크기를 확인하기 위해 Cohen's d를 사용하였다. 결과 : 실험군과 통제군 모두 중재 전과 후에 COPM 수행도와 만족도, GAS의 점수에서 통계적으로 유의한 차이를 보였다(p<.05). 집단 간의 중재 전과 후의 COPM 수행도 점수는 통계적으로 유의한 차이를 보이지 않았지만, Cohen's d 값의 결과 COPM 수행도(d=.913)에서 큰 효과를 보였다. COPM 만족도와 GAS 점수는 모두 두 집단 간 통계적으로 유의한 차이를 보였고(p<.05), Cohen's d 값의 결과 COPM 만족도(d=2.768), GAS 점수(d=2.786) 모두 큰 효과를 보였다. 결론 : 감각통합기반의 가족중심코칭이 감각통합기반의 일반적인 상담보다 ASD 아동의 작업 수행도와 만족도에 긍정적인 영향을 미치는 것으로 볼 수 있다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2005년도 ISMP
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• pp.23-34
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• 2005

Electronic interconnection and packaging is mainly performed in a planar, 2D design style. Further miniaturization and performance enhancement of electronic systems will more and more require the use of 3D interconnection schemes. Key technologies for realizing true 3D interconnect schemes are the realization of vertical connections, either through the Si-die or through the multilayer interconnect with embedded die. Different applications require different complexities of 3D-interconnectivity. Therefore, different technologies may be used. These can be categorized as a more traditional packaging approach, a wafer-level-packaging, WLP ('above' passivation), approach and a foundry level ('below' passivation) approach. We define these technologies as respectively 3D-SIP, 3D-WLP and 3D-SIC. In this paper, these technologies are discussed in more detail.

• Nuclear Engineering and Technology
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• 제55권12호
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• pp.4570-4575
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• 2023

Noise and Radio-frequency interference or RFI causes a significant restriction on the Free induction Decay or FID signal detection of the Nuclear Quadrupole Resonance procedure. Therefore, using this method in non-isolated environments such as industry and ports requires extraordinary measures. For this purpose, noise reduction algorithms and increasing signal-to-noise-and-interference ratio or SNIR have been used. In this research, sodium nitrite has been used as a sample and algorithms have been tested in a non-isolated environment. The resonant frequencies for the 150 g of test sample were measured at 303 K at about 1 MHz and 3.4 MHz. The main novelty in this study was, (1) using two types of antennas in the receiver to improve adaptive noise and interference cancellation, (2) using a separate helical antenna in the transmitter to eliminate the duplexer, (3) estimating the noise before sending the pulse to calculate the weighting factors and reduce the noise by adaptive noise cancellation, (3) reject the interference by blanking algorithm, (4) pulse integration in the frequency domain to increase the SNR, and (5) increasing the detection speed by new pulse integration technique. By interference rejection and noise cancellation, the SNIR is improved to 9.24 dB at 1 MHz and to 7.28 dB at 3.4 MHz, and by pulse integration 44.8 dB FID signal amplification is achieved, and the FID signals are detected at 1.057 MHz and 3.402 MHz at room temperature.

• 한국측량학회지
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• 제39권5호
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• pp.297-311
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• 2021

Around the world, there is an increasing interest in Digital Twin cities. Although geospatial data is critical for building a digital twin city, currently-established spatial data cannot be used directly for its implementation. Integration of geospatial data is vital in order to construct and simulate the virtual space. Existing studies for data integration have focused on data transformation. The conversion method is fundamental and convenient, but the information loss during this process remains a limitation. With this, standardization of the data model is an approach to solve the integration problem while hurdling conversion limitations. However, the standardization within indoor space data models is still insufficient compared to 3D building and city models. Therefore, in this study, we present a comparative analysis of data models commonly used in indoor space modeling as a basis for establishing a generic indoor space feature model. By comparing five models of IFC (Industry Foundation Classes), CityGML (City Geographic Markup Language), AIIM (ArcGIS Indoors Information Model), IMDF (Indoor Mapping Data Format), and OmniClass, we identify essential elements for modeling indoor space and the feature classes commonly included in the models. The proposed generic model can serve as a basis for developing further indoor feature models through specifying minimum required structure and feature classes.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2020년도 학술발표회
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• pp.287-287
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• 2020

2016년말 우리나라의 지하수 관측망은 국가지하수관측망, 지역지하수관측망, 수질전용측정망, 해수침투 관측망 등 다양한 목적하에 약 5,790개가 운영되고 있으며, 평균적으로 약 10년 정도의 관측 기간을 보유하고 있다. 이들 중에서 일 1회 이상 자동관측이 이루어지는 679개를 대상으로 지하수위 시계열자료의 특성을 분석하였다. ARIMA 분석 결과, AR(p) 모델은 전체의 56.8%인 386개, MA(q) 모델은 90.7%인 616개, Integration(d) 모델은 96.5%인 655개로 나타났다. AR(p) 모델중 가장 많은 경우를 보인 것은 AR(1), AR(2), AR(3) 등의 순이며, MA(q) 모델중 가장 많은 경우를 보인 것은 MA(2), MA(1), MA(3) 등의 순이며, Integration(d) 모델은 I(1), I(2)의 순으로 나타났다. AR(1) 모델이 가장 많은 것은 강우에 대한 지하수위의 교차상관의 lag time이 1 ~ 2일인 경우가 가장 많으므로 이전 시점의 지하수위에 의하여 현재 지하수위가 결정된다는 점을 의미한다. Integration이 많이 나타난 이유는 주기적 또는 지속적인 변동성이 지하수위에 나타나고 있음을 보여준다. 지하수위의 시계열 특성의 분류 및 그 원인을 평가하여 각 관측소별 지하수위 변동성을 정의함으로써 추후 지하수위 시계열자료의 분석 목적에 부합하는 자료 선별에 기여하고자 한다.

• 한국마이크로전자및패키징학회:학술대회논문집
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• 한국마이크로전자및패키징학회 2005년도 ISMP
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• pp.111-129
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• 2005

Pop provides OEMs and EMS with a platform to cost effectively expand options for logic + memory 3D integration - Expands device options by simplifying business logistics of stacking - Integration controlled at the system level to best match stacked combinations with system requirements - Eliminates margin stacking and expands technology reuse - Helps manage the huge cost impacts associated with increasing demand for multi media processing and memory. PoP is well timed to enable and leverage: - Mass customization of systems for different use (form, fit and function) requirements o Bband and apps processor + memory stack platforms - Logic transition to flip chip enables PoP size reduction o Area and height reduction. Industry standardization is progressing. Amkor provides full turn-key support for base package, memory package and full system integration.

• 한국정밀공학회지
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• 제12권3호
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• pp.32-41
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• 1995

In the analysis of metal forming processes by the finite element method, there are many numerical instabilities such as element locking, hourglass mode and shear locking. These instabilities may have a bad effect upon accuracy and convergence. The present work is concerned with improvement of stability and efficiency in two-dimensional rigid-plastic finite element method using various type of elemenmts and numerical intergration schemes. As metal forming examples, upsetting and backward extrusion are taken for comparison among the methods: various element types and numerical integration schemes. Comparison is made in terms of stability and efficiency in element behavior and computational efficiency and a new scheme of adaptive directional reduced integration is introduced. As a result, the finite element computation has been stabilized from the viewpoint of computational time, convergency, and numerical instability.

• 제어로봇시스템학회논문지
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• 제16권7호
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• pp.720-725
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• 2010

In AGPS method, user position can be obtained even in the shadow region by improving signal sensitivity. A hybrid long integration scheme employing both coherent and non-coherent integration method is commonly used in AGPS receivers. Because coherent loss increases as residual frequency become large, residual frequency should be minimized to maximize coherent integration gain. This paper presents performance analysis of residual frequency estimator using FFT in fine-time assistance AGPS method. Considering the hardware complexity and the estimation accuracy, optimal length of FFT is proposed for GPS L1 C/A signal. Signal sensitivity for estimating the residual frequency is also analysed. By field experimental results, it is found that the residual frequency can be successfully estimated using 1 second snap-shot data when GPS signal strength is larger than -150 dBm and its RMS error is 3Hz.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.119-123
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• 2004

This paper describes low temperature poly-Si (LTPS) TFT system on glass (SOG) technology developed in NEC. High resolution SOG-LCDs such as a 230 ppi reflective type LCD, a 2.5", 333 ppi 2D/3D autostereoscopic LCD, and a 2.1" single voltage driven full integration LCD for mobile applications and a 0.9", XGA light valve for projectors are reviewed from the perspective of the high resolution technologies