• The Journal of the Acoustical Society of Korea
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• v.23 no.2
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• pp.180-186
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• 2004

The presence of noise in speech signals degrades the performance of recognition systems in which there are mismatches between the training and test environments. To make a speech recognizer robust, it is necessary to compensate these mismatches. In this paper, we studied about an improvement of stochastic feature extraction based on band-SNR for robust speech recognition. At first, we proposed a modified version of the multi-band spectral subtraction (MSS) method which adjusts the subtraction level of noise spectrum according to band-SNR. In the proposed method referred as M-MSS, a noise normalization factor was newly introduced to finely control the over-estimation factor depending on the band-SNR. Also, we modified the architecture of the stochastic feature extraction (SFE) method. We could get a better performance when the spectral subtraction was applied in the power spectrum domain than in the mel-scale domain. This method is denoted as M-SFE. Last, we applied the M-MSS method to the modified stochastic feature extraction structure, which is denoted as the MMSS-MSFE method. The proposed methods were evaluated on isolated word recognition under various noise environments. The average error rates of the M-MSS, M-SFE, and MMSS-MSFE methods over the ordinary spectral subtraction (SS) method were reduced by 18.6%, 15.1%, and 33.9%, respectively. From these results, we can conclude that the proposed methods provide good candidates for robust feature extraction in the noisy speech recognition.

• Journal of Korean Academy of Nursing
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• v.41 no.4
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• pp.528-538
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• 2011

Purpose: The purpose of the study was to examine the effects of multisensory stimulation (MSS) using familiarity on persons with dementia (PWDs) residing in nursing homes in Korea. Methods: A nonequivalent control group with pre and posttests was used. Fifty one PWDs were included if they: 1) were over 65 yr old, 2) were diagnosed with dementia, 3) had no visual or speech impairments, 4) were able to communicate, and 5) had spent more than one month in a nursing home. The experimental group (n=25) received a 55 min MSS program twice a week for 10 weeks. The outcome variables included were cognition, activities of daily living, grip strength, depression, wandering, and aggressive behaviors. Repeated ANOVA was used for data analysis. Results: There were no significant differences in demographics or the main variables at pretest. Cognition, depression, wandering, and aggressive behaviors were significant over time between the two groups. Grip strength was only significant when accounting for interaction between group and time. Conclusion: An intervention of MSS using familiarity was marginally effective in improving cognition, depression, wandering, and aggression. Future study is suggested with a larger sample and longer treatment to retest the effects of MSS.

• Journal of Communications and Networks
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• v.14 no.2
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• pp.179-187
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• 2012

Power saving is one of the most important features that extends the lifetime of portable devices in mobile wireless networks. The IEEE 802.16e mobile broadband wireless access system adopts a power saving mechanism with a binary truncated exponent algorithm for determining sleep intervals. When using this standard power saving scheme, there is often a delay before data packets are received at the mobile subscriber station (MSS). In order to extend the lifetime of a MSS, the battery energy must be used efficiently. This paper presents a dynamically alternating sleep interval scheduling algorithm as a solution to deal with the power consumption problem. We take into account different traffic classes and schedule a proper sequence of power saving classes. The window size of the sleep interval is calculated dynamically according to the packet arrival rate. We make a tradeoff between the power consumption and packet delay. The method achieves the goal of efficiently reducing the listening window size, which leads to increased power saving. The performance of our proposed scheme is compared to that of the standard power saving scheme. Simulation results demonstrate the superior performance of our power saving scheme and its ability to strike the appropriate performance balance between power saving and packet delay for a MSS in an IEEE 802.16e mobile broadband wireless access system.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.3
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• pp.317-327
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• 2001

In this paper, a relation to calculate design moments for reinforced concrete(RC) bridges constructed by movable scaffolding system(MSS) is introduced. Through the time-dependent analysis of RC bridges considering the construction sequence, the structural responses related to the member forces and deflections are reviewed, and a governing equation for determination of the design moment, which includes the creep deformation, is derived on the basis of the displacement-force condition at every constructuion stage. By using the relation, the design moment and its variation over time can easily be obtained only with the elastic analysis results without additional time-dependent analysis. In addition, correlation studies with the results by rigorous numerical analyses are conducts to verify the applicability of the introduced relation, and a more reasonable guideline for the determination of design moments is proposed on the basis of the obtained moment envelop.

• Journal of the Korean Society of Systems Engineering
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• v.14 no.2
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• pp.33-40
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• 2018

This paper is based on the interim result of ongoing research and development project to develop a software system which support procurement activities, namely PeMSS (Procurement Engineering Management Support System). PeMSS is a system that enables development requirements for each equipment and help designing equipment meeting the purchase requirements. Procurement at EPC (Engineering Procurement and Construction) and operational stage of a plant is an important area that determines the integrity and profitability of the plant. Procurement of unsuitable equipment due to selection of suppliers that do not meet or omit critical requirements in purchase specification can result in enormous cost increase due to such as delay in EPC project, unsatisfactory performance and reduced plant operation time. In spite of the importance of the procurement engineering, there is a lack of support system for systematic preparation of purchase specification, so development of the procurement specification is basically relying on the experience of the engineers in charge. Accordingly, it is needed to develop the PeMSS to help procurement engineers develop procurement specification based on systems engineering approach. This paper introduces the design of the PeMSS.

• Journal of Distribution Science
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• v.22 no.8
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• pp.99-107
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• 2024

Purpose: The aim of this study is to explore the psychological characteristics of users in mobile distribution channels (MDC) during mobile shopping. Research design, data and methodology: A conceptual framework based on shopping satisfaction theory was developed, leading to the proposal of a research model to examine the relationships between emotional control (EC), emotional practice (EP), prudential buying tendency (PBT), prudential buying urge (PBU), prudential buying behavior (PBB), and mobile shopping satisfaction (MSS) in MDC. To validate the research model, 125 survey responses were collected from mobile shoppers, and the relationships among EC, EP, PBT, PBU, PBB, and MSS were analyzed using the PLS structural equation model. Results: The empirical analysis revealed that EC did not have a significant impact on PBT, while EP had a significant effect on PBT. Moreover, PBT was found to influence both PBU and PBB, with PBU significantly affecting PBB. Finally, the study found that PBB significantly influences MSS. Conclusions: This study elucidates the relationships among EC, EP, PBT, PBU, PBB, and MSS, providing valuable insights for enhancing consumer shopping satisfaction in MDC. Practically, the study suggests various strategies for personalized and differentiated mobile customer management. Theoretically, it contributes to the field by stimulating further research on prudent purchasing behavior in mobile commerce.

• Journal of Advanced Navigation Technology
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• v.11 no.4
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• pp.415-422
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• 2007

In this paper, we proposed a new dynamic channel allocation algorithm for TD-SCDMA with cross time slots. In order to reduce the interference in cross time slot, the mobile stations (MSs) are divided into two groups: the Near Group consisting of MSs near by the base station(BS) and the Far Group including the MSs far from the BS. The reverse link for MSs in the Near Group and forward link for MSs in the Far Group are allocated to the cross time slot. In cellular systems, a BS has multiple neighbor BSs. Some of neighbor BSs can operate in the same direction link while the others have cross time slot. Thus, it is required to determine which BS has the most significant impact in terms of interference. We divide each cell into 6 areas based on the direction of arrival of smart antenna and the most significant neighbor sector is determined with this division. The proposed allocation method and area division method can avoid the severe interference in cross time slots and increase the system capacity about 2%~9% compared to FCA, and 0.5%~1.3% compared to RCA.

• Safety and Health at Work
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• v.7 no.4
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• pp.347-353
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• 2016

Background: This study aimed to investigate the relation between key strike forces and musculoskeletal symptoms (MSS). Moreover, this study presents a key strike force measurement method to be used in a workplace setting. The correlation between key strike force characteristics and MSS was previously studied, but the measurement methods used either a single-key switch or force platforms applied under the keyboard. Most of the studies were conducted in a laboratory setting. The uniqueness of measurement methods in the current study is their ability to measure forces applied to a specific key in a workplace setting and to provide more information about specific key strike forces during typing. Methods: Twenty-four healthy computer workers were recruited for the study. The demographic questionnaire, and self-reported questionnaires for psychosocial status (General Nordic Questionnaire for Psychological and Social Factors at Work) and for detecting MSS were filled up, which later helped in dividing the participants into two groups (12 participants with pain and 12 without pain). Participants typed a predetermined text that utilized the instrumented keys multiple times. The dynamic forces applied to the keys were recorded and collected, using four thin and flexible force sensors attached to the preselected keys according to their location. Results: The results demonstrated that participants with high levels of MSS, specifically in the back and neck, in the last year exerted significantly higher key strike forces than those with lower levels of symptoms (p < 0.005). Conclusion: The key strike force exerted while typing on a keyboard may be a risk factor for MSS, and should therefore be considered in ergonomic evaluations and interventional programs.

• Journal of Korea Multimedia Society
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• v.14 no.3
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• pp.433-439
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• 2011

The positioning system based on wireless AP collects AP information distributed in the real world, stores it into database, and measures the position objects by comparing with searched AP information. The existing fingerprinting method is a probabilistic modeling method that acquires much of the data collected from one location upon database composition, and stores the average of the data for the sake of use it in positioning objects. Using the average value, however, may cause the probability of errors Such errors are fatal weaknesses for services based on the accurate position. This paper described the characteristics and problems of the previously used wireless AP positioning system, and proposed a method of using the AP DB and an MSS mechanism for outdoor positioning in order to solve the aforementioned problems. And the results obtained from experimental tests showed that the proposed method achieved very low error rate(27%) compared with the existing method.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.9 no.4
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• pp.113-124
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• 1989

In this study, we tried to extract the land-use change information of Seoul city using the multiple date images of the same geographic area. Multiple date image set is MSS('72, '79, '81, '93) and TM('85), and we carried out geometric correction, digitizing(due to the administrative boundary) in pre-processing process. In addition, we performed land-use classification with MLC(Maximum Likelihood Classifier) after improving the predictive accuracy of classification by filtering technique. At the stage of classification, ground truth data, topographic maps, aerial photographs were used to select the training field and statistical data of that time were compared with the classification result to prove the accuracy. As a result, urban area in Seoul has been increased('72 : 25.8 %${\rightarrow}$'81 : 43.0 %${\rightarrow}$'85 : 51.9 %) and Forest area decreased ('72 : 39.0 %${\rightarrow}$'85 : 28.4 %) as we estimated. Finally, it is concluded that the utilzation of satellite imagery is very effective, economical and helpful in the urban land-use/land-cover monitoring.