• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권11호
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• pp.1959-1975
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• 2011

Adaptive Bit Loading (ABL) in Multiple-Input Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFDM) is often used to achieve the desired Bit Error Rate (BER) performance in wireless systems. In this paper, we discuss some of the bit loading algorithms, compare them in terms of the BER performance, and present an effective and concise Adaptive Grouped Loading (AGL) algorithm. Furthermore, we propose a "weight factor" for loading algorithm to converge rapidly to the final solution for various data rate with variable Signal to Noise Ratio (SNR) gaps. In particular, we consider the bit loading in near optimal Singular Value Decomposition (SVD) based MIMO-OFDM system. While using SVD based system, the system requires perfect Channel State Information (CSI) of channel transfer function at the transmitter. This scenario of SVD based system is taken as an ideal case for the comparison of loading algorithms and to show the actual enhancement achievable by our AGL algorithm. Irrespective of the CSI requirement imposed by the mode of the system itself, ABL demands high level of feedback. Grouped Loading (GL) would reduce the feedback requirement depending upon the group size. However, this also leads to considerable degradation in BER performance. In our AGL algorithm, groups are formed with a number of consecutive sub-channels belonging to the same transmit antenna, with individual gains satisfying predefined criteria. Simulation results show that the proposed "weight factor" leads a loading algorithm to rapid convergence for various data rates with variable SNR gap values and AGL requires much lesser CSI compared to GL for the same BER performance.

• 한국터널지하공간학회 논문집
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• 제20권1호
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• pp.83-97
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• 2018

터널은 도로, 철도, 지하철과 같은 교통의 통로이자 수로, 전력구, 비축기지와 같은 특수목적을 위해 널리 활용되고 있으며, 터널의 사용 목적, 주변 지반조건 및 경제성에 따라 다양한 터널 형상으로 시공되고 있다. 이에 대해 기존 터널과 주변지반 및 구조물에 관한 연구는 꾸준하게 발표되었으나 단일 형상에 대해 터널굴착 시 주변 지반과 구조물의 거동을 분석한 연구들이 대다수이다. 터널의 붕괴사고는 지상 구조물의 붕괴사고 보다 막대한 인적, 물적 손실을 가져오기 때문에 터널 굴착 및 주변지반의 거동을 관측하고 분석하는 작업은 매우 중요하며, 단일 형상이 아닌 다양한 터널 형상에 대한 연구가 필요할 것으로 판단된다. 따라서, 본 연구는 trapdoor장치를 이용한 실내 모형시험을 통해 군말뚝 하부에 터널 정거장 굴착 시 주변지반의 거동을 측정하였다. 이때 터널 정거장 형상의 단면을 arch와 box 형태로 제작하였으며, 각 터널 정거장 형상 별 0.1B, 0.25B, 0.4B로 터널과 군말뚝 간 이격거리를 다르게 하여 다양한 조건에서의 지반거동을 분석하였다. 또한, 근거리 사진계측 및 이미지프로세싱 기법을 통해 지반의 거동을 관측하였으며, 유한요소 수치해석을 통해 실내 모형시험, 근거리 사진계측의 결과와 비교 분석하였다.

• The Journal of Korean Physical Therapy
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• 제1권1호
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• pp.83-102
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• 1989

The purpose of this study is to analyse the factors affecting rehabilitation of physically disabled persons . Data were collected from 118 physically disabled persons who were registered at facilities for disabled persons by an interview surevey Conducted from October 17 to October 26, 1988. The three facilities for the survey were selected by stratified random sampling. The results were as follows : 1. Using factor analysis, 10 variables were-grouped into 4 factors : physical need, need for social problem-solving, need for social interaction and educational need. The proportion of variance explained by these factors was $58.3\%$. 2. Age, religion and job were significantly related to the functional life scale score, but other variables were not. 3. Family APGAR score and severity of disability were significantly rotated to the functional life scale score. 4. From the multiple regression analysis on rehabilitation of the physically disabled person, the following: three variables were statistically significant : age, severity of disability and family functioning. These results suggest that age, severity of disability and family functioning variables are important factors for rehabilitation of physically disabled persons. Since the family functioning variable can be controlled by care, rehabilitation team should monitor the variable closely to improve the efficiency of rehabilitation. Because of their implication for further study, some variables, other than those considered here, are needed for studying rehabilitation of physically disabled persons.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.115.1-115
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• 2003

Post-harvest decay, caused by Penicillium spp. is a serious problem of fruits worldwide. Morphological characteristics and molecular markers were used to characterize 22 Penicillium isolates from apples, 18 isolates from pears, 60 from oranges and 18 from grapes and 23reference isolates representing related Penicillium spp. to assess their diversity and resolve their taxonomy. Based on morphological and physiological characteristics, the isolates were grouped as identical or very similar to P. digitatum, P. italicum, P. ulaiense or very similar to P. crustosum, P. expansum, P. solitum and unidentified Penicillium spp. Based on sequence comparisons of ITS region, variable site were presented within and among the species, but there variation were not correlated with the species. Cluster analyses of AP-PCR fragment patterns using UP and L45 primer and the -tubulin gene sequence, the Penicillium species were segregated into distinct groups. Particularly. the -tubulin partial sequence data provided support for species concepts based on morphological and physiological characteristics.

• 한국주거학회:학술대회논문집
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• 한국주거학회 1995년도 학술발표대회논문집 하
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• pp.77-83
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• 1995

This study explores the patterns of housing-related attitudes and the kind of needs for shared community spaces among small-sized apartment housing dwellers. The major findings are as follows. The majority of the dwellers are in strong need of common spaces, especially for children's activities, Social gathering and physical exercises. Housing-related attitudes are found and grouped into 4categories the propensity to making up common society, the propensity to pursuing the quality of neighborhood, the propensity to orienting natural environment, and the propensity to participating in community. The intensity of the needs depends on family lifecycle, employment status of housewives, and the size of floor space. The propensity to making up common society and pursing the quality of neighborhood have stronger impact on needs of shared community space. This study reveals that the sense of community orientation is the most powerful predictor variable for shared community space needs .

• 한국주거학회논문집
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• 제8권3호
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• pp.91-98
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• 1997

This study explores the patterns of housing-related attitudes and the kind of needs for shared community spaces among small-sized apartment housing dwellers. The major findings are as follows. The majority of the dwellers are in a strong need of common spaces. especially for children's activities. social gathering and physical exercises. Housing consciousness can be grouped into 4 categories the propensity to making up common society. the propensity to pursuing the quality of neighborhood. the propensity to orienting natural environment. and the propensity to participating in community. Families with children in primary school are more likely to get involved in the community and the common society than those with children in high school or those in the stage of launching a family. The propensity to making up common society and pursing the quality of neighborhood have stronger impact on needs for shared community space. This study reveals that the sense of community orientation is the most powerful predictor variable for shared community space needs.

• Journal of Welding and Joining
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• 제20권1호
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• pp.83-90
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• 2002

Metal Transfer in gas metal arc (GMA) welding is a complex phenomenon affected by many parameters of the welding conditions and material properties. In this research, the correlation equation between the welding condition and detaching droplet size and detaching velocity in GMA welding was studied via recession analysis on the results of numerical analysis using the volume-of-fluid (VOF) method. Welding parameters and material properties were grouped into three dimensionless numbers and detaching droplet size was expressed as the function of them. Second order and exponential multi-variable correlation forms were assumed, and the coefficients of these equations were calculated for globular and spray modes as well as entire transfer modes. Applying correlation equation into available experimental data, it shows good agreement.

• The Journal of Asian Finance, Economics and Business
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• 제8권11호
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• pp.31-39
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• 2021

This study empirically examines the proposition that the domestic fundamentals of a nation can emerge as absorptive capacity factors to reap the benefits of inward FDI. The study is contextualized in Asia, set from1982 to 2017, and data is grouped into low-income and lower-middle-income economies, in comparison to high-income and upper-middle-income economies, catering to different geographical regions within Asia. The investigation is based on a series of absorptive capacity factors such as infrastructure, human capital, domestic credit, and health indicator. The methodological analysis is premised on dynamic panel structure and employs the Generalized Method of Moments (GMM) estimation technique. The empirical findings suggest that that the infrastructure variable appears to be the major absorptive capacity factor for both groups of countries. The health indicator, on the other hand, can help reap the benefits of inward FDI, but only if the threshold level is met. The selected economies must achieve this threshold level to reap the benefits of FDI. To absorb the benefits of inward FDI, countries must be proactive in providing sound infrastructure and implementing proper healthcare measures.

• Educational Technology International
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• 제24권1호
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• pp.1-27
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• 2023

This study aimed to examine an augmented reality-based teaching simulation in a mobile application. We examined how AR-enabled interactions affect users' perceived scenario usefulness and avatar realism. The participants were forty-six undergraduate students. We randomly grouped them into two conditions: AR and Non-interactive video groups with equal sample sizes. This study employed an experimental design approach with a one-way multivariate analysis of variance with repeated measures. The independent variable is the presence/absence of AR interaction with a mobile application. The dependent variables were avatar realism and scenario usefulness. The measures explored how the student avatar's emotional intensity in a scenario influences user perception. The results showed that participants in the AR-interaction group perceived avatar realism significantly higher than those in the non-interactive video group. Also, participants perceived the high emotional intensity scenario (aggression toward peers) to be significantly higher usefulness than the low emotional intensity scenario (classroom disruption).

• 한국터널지하공간학회 논문집
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• 제19권3호
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• pp.355-373
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• 2017

도심지에서의 터널굴착은 상부구조물과의 상호거동에 대한 이해가 필수적이다. 도심지에 사용중인 대부분의 구조물은 말뚝기초로 상부의 하중을 지지하고 있어, 터널 굴착 시 반드시 영향을 받는다. 따라서 본 연구에서는 실내모형시험을 통해 기존의 군말뚝 기초 하부 터널굴착에 따른 축력 분포와 지반의 거동을 분석하였다. 말뚝 기초는 2, 3 열 말뚝으로 가정되었으며, 말뚝 선단부와 터널 천단부의 이격거리는 터널직경에 대한 일반화를 위해 터널 직경(D) 대비 0.5D, 1.0D 그리고 1.5D로 고려되었다. 지반은 약 30%의 상대밀도(Dr)를 가지는 느슨한 사질토로 형성되었으며, 말뚝의 축력 분포를 측정하기 위해 말뚝에 변형률게이지(strain gauge)를 부착하였다. 또한, 이격거리에 따른 군말뚝의 침하와 인접지반의 침하를 변위센서(linear variable differential transformer; LVDT)와 다이얼게이지(dial gauge)를 통해 측정였으며, 터널굴착에 따른 지중의 변형을 근거리사진계측기법(close range photogrammetric technique)을 통해 측정하였다. 수치 해석을 통해 실내모형시험 및 근거리사진계측 결과와 비교 분석하였다. 본 연구에서는 체적손실율(volume loss; $V_L$) 개념을 이용하여 터널굴착을 모사하였으며, 1.5%로 적용되었다. 연구결과, 이격거리가 멀어질수록 말뚝의 축력감소는 작게 나타났으며, 침하량은 모두 유사한 경향을 나타내었다. 특히, 말뚝 선단부와 터널 천단부의 이격거리가 0.5D에서 1.0D로 증가할 때 축력과 침하량의 가장 큰 감소율이 가장 큰 것으로 나타났다.