• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.317-326
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• 2014

Slips and falls are associated with many public injuries in Korea. It is also estimated that slipping are major contributors to slip, trip and fall injury burden. The primary purpose of the present study is to determine if, and to what extent, the standard could be improved in present environment. In order to fulfill our objective, the regulations in Korea and foreign countries were investigated and reviewed. Many kind of standard, mandatory documents and guideline were also reviewed. And then, regulations, standard, guideline etc. reviewed were compared with each others. Also, some criteria was developed in this study. Standard and criteria developed in this study will help to prevent slip, trip, and fall injuries.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.81-88
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• 2014

A number of screening tools have been developed to evaluate the human balance capability. Many of them were designed to identify the elderly with falling risk. Three different screening tools, which have been well used many clinical fields, were used in this study. The purpose of this study was to evaluate balance capability in facilities maintenance workers in korea. There were no statistical significance between male and female when evaluated with three different screening tools. However, significant differences were found among the age groups irrespective of gender when evaluated with three different screening tools. The results of three different screening tools in korea showed poor values compared with previous results. These results revealed that facilities maintenance workers faced more critical falling risk in korea.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.697-705
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• 2009

The Pearson chi-squared statistic or the deviance statistic is widely used in assessing the goodness-of-fit of the generalized linear models. But these statistics are not proper in the situation of continuous explanatory variables which results in the sparseness of cell frequencies. We propose a goodness-of-fit test statistic for the cumulative logit models with ordinal responses. We consider the grouping of a dataset based on the ordinal scores obtained by fitting the assumed model. We propose the Pearson chi-squared type test statistic, which is obtained from the cross-classified table formed by the subgroups of ordinal scores and the response categories. Because the limiting distribution of the chi-squared type statistic is intractable we suggest the parametric bootstrap testing procedure to approximate the distribution of the proposed test statistic.

• JSTS:Journal of Semiconductor Technology and Science
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• v.16 no.6
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• pp.817-824
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• 2016

A simultaneous bidirectional transceiver over a single wire has been developed in a 65 nm CMOS technology for a command and control bus. The echo signals of the simultaneous bidirectional link are cancelled by controlling the decision level of receiver comparators without power-hungry operational amplifier (op-amp) based circuits. With the clock information embedded in the rising edges of the signals sent from the source side to the sink side, the data is recovered by an open-loop digital circuit with 20 times blind oversampling. The data rate of the simultaneous bidirectional transceiver in each direction is 75 Mbps and therefore the overall signaling bandwidth is 150 Mbps. The measured energy efficiency of the transceiver is 56.7 pJ/b and the bit-error-rate (BER) is less than $10^{-12}$ with $2^7-1$ pseudo-random binary sequence (PRBS) pattern for both signaling directions.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.4
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• pp.1307-1313
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• 2015

Colangiocarcinoma (CCA) is a progressively fatal disease which generally occurs due to malignant transformation of hepatic biliary cholangiocytes. The incidence of CCA has been increasing worldwide and there is an urgent requirement for effective diagnosis and treatment strategies against this devastating disease. Different factors including liver-fluke infestation, viral hepatitis, exogenous nitrosamine-mediated DNA damage, and chronic inflammation have been linked to CCA genesis. However, the risk factors and underlying complex mechanisms leading to development of CCA are not sufficiently understood to devise an effective targeted treatment therapy. In this review, we summarize currently known epidemiological and pathological aspects of the disease and briefly describe various potential biomarkers and experimental anticancer phytochemicals related to CCA research. In addition, we also sum up recent findings that link chronic inflammation of hepatic biliary cholangiocytes with CCA. The collective information concisely presented in this article would provide useful insights into the current understanding of this cancer.

• Proceedings of the Korea Contents Association Conference
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• 2005.11a
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• pp.596-600
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• 2005

In High-speed Portable Internet system to improve performance of whole system, adaptive modulation and coding technology is used, this technology changes modulation and encoding techniques depending on wireless channel environment. Modulation technology that is used in High-speed Portable Internet system is BPSK, QPSK, 16QAMs and 64QAMs. If terminal is distant from base station transceiver system, BPSK or QPSK technology Is used and 16QAMs or 64QAM technology is used if is near in the base station transceiver system. In this paper, number of sub-channel in each modulation technology minimized total transmitting number of PDU is analyzed for efficient radio resources usage. For this, simulation is conducted and the results are presented at High-speed Portable Internet system environments.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.460-469
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• 2012

The WiMedia Alliance has specified a Distributed Medium Access Control (D-MAC) protocol based on UWB for high speed wireless home networks and WPANs. In this paper, we propose a novel cooperative communication protocol adaptive to current UWB link transmission rate. The proposed cooperative communication protocol has compatibility with current WiMedia D-MAC and Wireless USB standard and is executed at each device according to a Relay Node Selection (RNS) criterion.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.4
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• pp.45-52
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• 2011

In the real-field of control cases for robot manipulators, there always exists a modeling error, which results the model has the uncertainties in its parameters and/or structure. In many modem applications, digital computers are extensively used to implement control algorithms to control such systems. The discretization of the nonlinear dynamic equations of such systems results in a complicated discrete dynamic equations. Therefore, it will be difficult to design a discrete-time controller to give good tracking performances in the presence of certain uncertainties. In this paper, a discrete-time sliding mode control algorithm for nonlinear and time varying robot manipulators with uncertainties is presented. Sufficient conditions for guaranteeing the convergence of the discrete-time SMC system are derived. As example simulations, the proposed SMC algorithm is applied to a two-link robotic manipulator with unknown dynamics. The results of the simulation indicate that the developed control scheme is effective in manipulators and electro-mechanical system control.

• Computers and Concrete
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• v.16 no.3
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• pp.415-428
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• 2015

Study on flexural retrofitting of RC beams using external bars with additional intermediate anchorages at soffit is reported in this paper. Effects of varying number of anchorages in the external bars at soffit were studied by finite element analysis using ANSYS 12.0 software. The results were also compared with available experimental results for beam with only two end anchorages. Two sets of reference and retrofitted beam specimens with two, three, four and five anchorages were analysed and the results are reported. FE modeling and non-linear analysis was carried out by discrete reinforcement modeling using Solid65, Solid45 and Link8 elements. Combin39 spring elements were used for modeling the frictional contact between the soffit and the external bars. The beam specimens were subjected to four-point bending and incremental loading was applied till failure. The entire process of modeling, application of incremental loading and generation of output in text and graphical format were carried out using ANSYS Parametric Design Language.

• International Journal of Contents
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• v.16 no.4
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• pp.39-49
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• 2020

The goal of this research was to understand the patterns of multidimensional engagement in MOOCs. An email with an online survey link was sent to enrollees in an MOOC course. The survey included 35 questions asking about engagement, teaching presence, and learning persistence. The items were validated in the literature, revised for the MOOC setting, reviewed by four professionals in the field of educational technology, and used in the study. A heterogeneous group of 170 individuals gathered through convenience sampling participated in the study. With cluster analysis of the engagement data, three groups were identified: Cluster1, 2, and 3. Cluster 1 scored high on behavioral, emotional, and cognitive engagement. Cluster 2 scored high on behavioral aspects but low on emotional and cognitive engagement. Cluster 3 scored low on behavioral and cognitive engagement but high on emotional aspects. The study addressed cluster-specific learner characteristics and differences in perceived teaching presence and learning persistence. Design strategies pertaining to each cluster were further discussed. These strategies may guide instructors and practitioners in the design and management of MOOCs and should be further validated through future studies.