• Survey Research
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• v.12 no.3
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• pp.25-48
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• 2011

In this paper, we overview the sample design, sampling error, non-response rate and prediction errors of the exit poll conducted for 2010 local elections and discusses how to detect a prediction bias in exit poll. To investigate the bias problem in exit poll in regional(Si-Do) level, we analyze exit poll data for 2007 presidential election and 2006 local elections as well as 2010 local elections in Korea. The measure of predictive accuracy A proposed by Martin et al.(2005) is used to assess the exit poll bias. The empirical studies based on three exit polls clearly show that there exits systematic bias in exit poll and the predictive bias of candidates affiliated to conservative party (such as Hannara-Dang) is serious in the specific regions. The result of this study on systematic bias will be very useful to improving the exit poll methodology in Korea.

• Nuclear Engineering and Technology
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• v.41 no.3
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• pp.247-270
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• 2009

This paper reviews studies on information searching behavior in process control systems and discusses some implications learned from previous studies for use in human factors studies on nuclear power plants (NPPs) main control rooms (MCRs). Information searching behavior in NPPs depends on expectancy, value, salience, and effort. The first quantitative scanning model developed by Senders for instrument panel monitoring considered bandwidth (change rate) of instruments as a determining factor in scanning behavior. Senders' model was subsequently elaborated by other researchers to account for value in addition to bandwidth. There is also another type of model based on the operator's situation awareness (SA) which has been developed for NPP application. In these SA-based models, situation-event relations or rules on system dynamics are considered the most significant factor forming expectancy. From the review of previous studies it is recommended that, for NPP application, (1) a set of symptomatic information sources including both changed and unchanged symptoms should be considered along with bandwidth as determining factors governing information searching (or visual sampling) behavior; (2) both data-driven monitoring and knowledge-driven monitoring should be considered and balanced in a systematic way; (3) sound models describing mechanisms of cognitive activities during information searching tasks should be developed so as to bridge studies on information searching behavior and design improvement in HMI; (4) the attention-situation awareness (A-SA) modeling approach should be recognized as a promising approach to be examined further; and (5) information displays should be expected to have totally different characteristics in advanced control rooms. Hence much attention should be devoted to information searching behavior including human-machine interface (HMI) design and human cognitive processes.

• Korean Institute of Interior Design Journal
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• no.26
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• pp.112-120
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• 2001

This study investigated the extend to which the facilities satisfactorily accommodate people with different disabilities and their specific needs for improving the facilities. Systematic interviews were conducted with 90 disabled people using the non-propertionate stratified cluster random sampling method. Frequency analysis, Chi-square tests, Duncan tests, and analysis of variance(ANOVA) were employed for data analysis. The findings indicated that the respondents' assessment of accommodations and needs for improving accommodations differed by the type of disabilities. People with physical disabilities were the least satisfied with stairs, followed by seating in stadiums and/or theaters. For people with visual disabilities, the lack of guidance and information facilities was the most difficult problem. People with hearing disabilities often pointed out difficulties in using public telephones. meanwhile, people with physical disabilities asked for easy access to assistive devices and improved mobility-related circumstances. yet people with visual disabilities expected to improve way-finding relevant issues, such as detectable warnings on walking surfaces and guidance and information facilities, whereas people with hearing disabilities desired to develop hearing-aid equipments, such as TDD and assistive listening systems.

• Journal of the Korean Home Economics Association
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• v.44 no.2 s.216
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• pp.71-81
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• 2006

The purpose of this study was to analyze the preferences for the physical features of senior congregate housing. The survey was conducted among middle-aged people in their fifties, who lived in Seoul, using the systematic random sampling method. The data were collected from November 3, 2003 to November 14, 2003 and the final subjects consisted of 498 respondents. Various statistical methods such as frequency, mean, cross tabulation, t-test, factor analysis, and multiple regression were used in this study. The results of this study were as follows. Firstly, most of the respondents preferred 55 to $70m^2$ sized individual units and they rarely wanted smaller units of less than $35m^2$. Individual units of one or two bedrooms were also preferred by future users. Small towns were preferred to large complex. For housing type, they preferred row houses or single detached houses to high-rise apartments. Secondly, there were no significant statistical differences between income and the preference of the physical features. From the results, we concluded that senior congregate housing should be developed not only in accordance with the users' preferences but also over a certain minimum physical quality level, regardless of the users' income.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.8
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• pp.123-134
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• 2022

In 2021 One Tambon One Product (OTOP) food products reached $3,447 billion domestically and $200 million internationally. Mirroring Japan's highly successful OVOP (One Village One Product) poverty reduction and rural employment program, Thailand's OTOP program has since become a global model of success as well. From May through June 2022, OTOP snack food vendor entrepreneurs were contacted and asked to contribute their opinions about what factors affected their enterprise's food product quality. Using systematic random sampling across six Thai regions, 311 export entrepreneurs, production managers, and marketing managers participated. The results revealed that product innovation (PDTI), process innovation (PCSI), packaging design (PKD), and the 4P marketing mix (4PMM) all positively influenced OTOP snack food product quality (PDQ), which, when combined, had a total effect R² value of 27%. Also, the latent variable TE values for PDTI, PKD, 4PMM, and PCSI, were 0.38, 0.29, 0.22 and 0.11, respectively. Seven of the nine hypotheses examined were supported, with packaging design (PKD) determined to have the greatest influence on the 4P marketing mix (4PMM).

• Design & Manufacturing
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• v.15 no.1
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• pp.48-56
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• 2021

The quality of products produced by injection molding process is greatly influenced by the process variables set on the injection molding machine during manufacturing. It is very difficult to predict the quality of injection molded product considering the stochastic nature of manufacturing process, because the process variables complexly affect the quality of the injection molded product. In the present study we predicted the quality of injection molded product using Artificial Neural Network (ANN) method specifically from Multiple Input Single Output (MISO) and Multiple Input Multiple Output (MIMO) perspectives. In order to train the ANN model a systematic plan was prepared based on a combination of orthogonal sampling and random sampling methods to represent various and robust patterns with small number of experiments. According to the plan the injection molding experiments were conducted to generate data that was separated into training, validation and test data groups to optimize the parameters of the ANN model and evaluate predicting performance of 4 structures (MISO1-2, MIMO1-2). Based on the predicting performance test, it was confirmed that as the number of output variables were decreased, the predicting performance was improved. The results indicated that it is effective to use single output model when we need to predict the quality of injection molded product with high accuracy.

• Journal of Forest and Environmental Science
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• v.38 no.3
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• pp.141-151
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• 2022

Soil seed banks as natural storage of plant seeds play an important role in the maintenance and regeneration of watershed. Natural regeneration potential of the soil seed bank of Land use types (LUTs) in Ogun River watershed (ORW) was investigated. ORW was stratified using proportionate sampling technique into Guinea Savannah (GS), Rainforest (RF) and Swamp Forest (SF) Ecological Zones (EZs). Three LUTs: Natural Forest (NF), Disturbed Forest (DF) and Farmland (FL) were purposively selected in GS: GSNF, GSDF, GSFL; RF: RFNF, RFDF, RFFL and SF: SFNF, SFDF, SFFL, respectively. Systematic line transects was used in the laying of the sample plots. Sample plots of 25 m×25 m were established in alternate positions. Ten 1 m×1 m quadrats were randomly laid for soil core sampling from previously randomly selected ten plots. The core samples (10) were pooled per plot in each LUT and placed in individual trays. Ten trays with sterilized soil were used as control. The trays were watered regularly and checked for seedlings emergence fortnightly for 18 months. The experimental design used was 3×3 factorial experiments. ANOVA, Diversity index (H') and Similarity index (SI) were used to analyze the data. There was significant difference in seedling emergence among ecological zones and land use types (p<0.05). A total of 4,400 seedlings emerged from the soil samples. All species were distributed among 32 families. FL in the RF had the highest number of germinated seeds (705±37.33 seedlings) followed by DF in the RF (701±49.6 seedlings). The lowest emergence was in NF of the SF (199±28.41 seedlings). DF in the RF had highest number of species (34) distributed among 22 families. Emergence from soil seed bank of NF in ORW was generally with more of tree species than herbs that were predominant in FL and DF.

• Smart Structures and Systems
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• v.14 no.6
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• pp.1221-1245
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• 2014

Real-time hybrid simulation (RTHS) is a promising cyber-physical technique used in the experimental evaluation of civil infrastructure systems subject to dynamic loading. In RTHS, the response of a structural system is simulated by partitioning it into physical and numerical substructures, and coupling at the interface is achieved by enforcing equilibrium and compatibility in real-time. The choice of partitioning parameters will influence the overall success of the experiment. In addition, due to the dynamics of the transfer system, communication and computation delays, the feedback force signals are dependent on the system state subject to delay. Thus, the transfer system dynamics must be accommodated by appropriate actuator controllers. In light of this, guidelines should be established to facilitate successful RTHS and clearly specify: (i) the minimum requirements of the transfer system control, (ii) the minimum required sampling frequency, and (iii) the most effective ways to stabilize an unstable simulation due to the limitations of the available transfer system. The objective of this paper is to establish a stability switch criterion due to systematic experimental errors. The RTHS stability switch criterion will provide a basis for the partitioning and design of successful RTHS.

• Journal of Computing Science and Engineering
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• v.2 no.2
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• pp.200-219
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• 2008

The effective management of uncertainty is one of the most fundamental problems in medical decision making. According to the literatures review, most medical decision models rely on point estimates for input parameters. However, it is natural that they should be interested in the relationship between changes in those values and subsequent changes in model output. Therefore, the purpose of this study is to identify the ranges of numerical values for which each option will be most efficient with respect to the input parameters. The Nonhomogeneous Poisson Process(NHPP) was used for describing the behavior of aging chronic diseases. Three kind of failure models (linear, exponential, and power law) were considered, and each of these failure models was studied under the assumptions of unknown scale factor and known aging rate, known scale factor and unknown aging rate, and unknown scale factor and unknown aging rate, respectively. In addition, this study illustrated developed method with an analysis of data from a trial of immunotherapy in the treatment of chronic Granulomatous disease. Finally, the proposed design of Bayesian value of information analysis facilitates the effective use of the computing capability of computers and provides a systematic way to integrate the expert's opinions and the sampling information which will furnish decision makers with valuable support for quality medical decision making.

• The KIPS Transactions:PartD
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• v.13D no.4 s.107
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• pp.619-624
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• 2006

Currently domestic game market rapidity is developmental but the game production process does not become systematization. Also it is bringing the failure of game that problem point of conversation between game planner and game developer.. The research which to conversation between game planner and game developer it sees does extracting a game element to expressed game characteristics from the product for game planning and it change extracted element into class and In order to express the relationship of element for it presents a relationship of class. Instance research it leads. It grasps a relationship among extracted classes and it supports systematic game planning.