• Journal of Digital Convergence
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• v.8 no.3
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• pp.95-113
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• 2010

The mobile commerce (m-commerce) has very high market value unlike other technology innovation areas in IT industries and also changing rapidly. Therefore, it is fact that the development of the effective business strategy is challenging in a digital convergence era of m-commerce context. In most of the researches, m-commerce has dealt with conceptual study such as establishment of definition. There are not many studies of influence of information valuation evaluation on users' satisfaction have done so far. In this paper, we have reported a theoretical study as well as empirical analysis and examined an influence of information valuation evaluation have on users' satisfaction. A questionnaire was constructed and data were collected from 192 users of m-commerce system. The results indicated that users' satisfaction was affected by information valuation evaluation and difference between cost satisfaction and service quality satisfaction according to users' specialty.

• Journal of Broadcast Engineering
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• v.18 no.3
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• pp.435-444
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• 2013

ATSC terrestrial DTV system can support high data rates for HDTV(High Definition Television) service, but it suffers from significant performance degradation caused by multipath fading. Thus, it is necessary to analyze multipath fading effects in order to enhance the DTV reception performance. Generally, DTV channel profile can be obtained by auto-correlation between reference pseudo random signal and received DTV signal. However, in the ATSC terrestrial DTV system, the estimation performance of DTV channel profile may be decreased due to the VSB modulation features. In this paper, improved DTV channel profile measurement technique is analyzed and proposed.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1537-1540
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• 2009

홍수통제소는 수문조사, 하천유량관리, 홍수예보 등 다양한 업무를 수행하고 있다. 수문조사는 물 관리를 위한 기본 자료 확보와 수자원이라는 국가의 귀중한 자산을 정량화하는 중요한 업무이다. 하천유량 관리는 하천의 물을 합리적으로 관리하여 공익을 증진하고 모든 사람들이 혜택을 고루 향유할 수 있도록 배분하는 업무이다. 홍수예보는 큰 비에 의해 유역에서 발생할 수 있는 홍수의 규모를 예측하고 그 수치를 유관기관에 제공하여 홍수를 사전에 대비토록 함으로써 홍수피해를 최소화 할 수 있도록 하는 업무이다. 상기 언급된 홍수통제소의 주요 업무들을 효율적으로 수행하기 위하여 낙동강홍수통제소에서는 전년도 시험연구과제로서 "홍수통제소 발전방안"이라는 주제로 낙동강 홍수통제소의 발전을 위한 기본적인 개선항목 중 홍수통제소 홍보동영상 제작을 통한 통제소 홍보 및 이미지 제고, 수자원 자료실의 전산화와 관측소 이력 및 기본제원 시스템화 등을 통한 업무의 효율성 증대를 위하여 연구를 수행하였다. 금년은 지난해 개선된 업무들을 토대로 업무 효율성 증대를 도모하고자 한다. 현재 낙동강홍수 통제소에서 관리되고 있는 수문관측소는 239개소(수위 및 우량, 10분 단위)으로, 이들 관측소에 대한 효율적인 관리와 정확한 자료 생성을 위해서는 해당 내용에 대한 체계적이고 합리적인 관리가 필요하다. 이를 위하여 관측소 이력관리 프로그램을 시험적으로 운영을 하여 매년 실시되는 분기별 관측소 정기점검 결과를 업로드 시켜 관련 직원들이 내용을 공유할 수 있도록 추진하고 있다. 이는 수문자료의 정확한 검보정에도 활용될 수 있을 뿐만 아니라 다양한 정보를 체계적으로 관리하여 향후 추가적인 업무 효율화를 위하여도 이용될 수 있을 것이다.

• Journal of Korea Society of Industrial Information Systems
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• v.19 no.1
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• pp.77-85
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• 2014

Medicine-bottle classification algorithm to avoid medicine accidents must be robust to a geometric change such as rotation, size variation, location movement of the medicine bottles. In this paper, we propose an algorithm to classify the medicine bottles exactly in real-time by using SIFT(Scale Invariant Feature Transform) which is robust to the geometric change. In first, we classify medicine bottles by size using minimum boundary rectangle(MBR) of medicine bottles as a striking feature in order to classify the medicine bottles. We extract label region in the MBR and the region of interest(ROI) considering rotation. Then, we classify medicine bottles using SIFT for the extracted ROI. We also simplify the number of octave of SIFT in order to improve a process speed of SIFT. We confirm to classify all the medicine bottles exactly as a result of performance evaluation of the proposed algorithm about images of 250 medicine bottles. We also confirm to improve the process time more than twice the processing time by simplifying the number of octave of SIFT.

• Journal of Advanced Navigation Technology
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• v.13 no.4
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• pp.482-489
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• 2009

This paper proposes a CW(Continuous-Wave) bio-radar applying a new adaptive noise canceller based on ALE(Adaptive Line Enhancer) which can remove the Gaussian noise and system noise. Recently the research works on this CW bio-radar which can be used to detect heartbeat and respiration are advanced by the university and research facility. Although the researches describe CW bio-radar not only is vulnerable for the Gaussian noise but also has a disadvantage of decreasing the heart-rate accuracy due to the noise, the researches do not demonstrate the effective method for removing the noise component in a baseband signal. In this paper, a CW bio-radar applying the new adaptive noise canceller based on ALE which can remove the noise component is proposed. This paper compares and analyzes the performance for increasing the heart-rate accuracy according to removing the Gaussian noise and system noise in the baseband signal through the quadrature receiver which can alleviate the demodulation sensitivity to target position.

• Journal of the Korean Data and Information Science Society
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• v.28 no.3
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• pp.533-545
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• 2017

Quantile regression models provide a variety of useful statistical information by estimating the conditional quantile function of the response variable. However, the traditional linear quantile regression model can lead to the distorted and incorrect results when analysing real data having a nonlinear relationship between the explanatory variables and the response variables. Furthermore, as the complexity of the data increases, it is required to analyse multiple response variables simultaneously with more sophisticated interpretations. For such reasons, we propose a multivariate quantile regression tree model. In this paper, a new split variable selection algorithm is suggested for a multivariate regression tree model. This algorithm can select the split variable more accurately than the previous method without significant selection bias. We investigate the performance of our proposed method with both simulation and real data studies.

• Geophysics and Geophysical Exploration
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• v.5 no.3
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• pp.169-177
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• 2002

We develop the weighted-averaging finite-element method which uses four kinds of element sets. By constructing global stiffness and mass matrices for four kinds of element sets and then averaging them with weighting coefficients, we obtain a new global stiffness and mass matrix. With the optimal weighting coefficients minimizing grid dispersion and grid anisotropy, we can reduce the number of grid points required per wavelength to 4 for a $1\%$ upper limit of error. We confirm the accuracy of our weighted-averaging finite-element method through accuracy analyses for a homogeneous and a horizontal-layer model. By synthetic data example, we reconfirm that our method is more efficient for simulating a geological model than previous finite-element methods.

• Clinics in Shoulder and Elbow
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• v.11 no.1
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• pp.13-18
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• 2008

Successful treatment of any pathological condition of the shoulder requires an accurate diagnosis. Physical examination represents an integral part of the assessment of shoulder disorders. Pain, loss of strength, decreased range of motion, and instability are the most common symptoms caused by a great variety of different shoulder pathologies. Therefore, a sophisticated clinical approach to the patient with shoulder pathology is essential. A standardized evaluation including a variety of diagnostic tests and clinical assessments improves the diagnostic accuracy by specifically examining one component of the shoulder complex. In most cases a careful physical examination will establish or suggest a diagnosis and special investigative techniques such as imaging procedures can be applied more selectively for confirmation or further evaluation of the pathological entity.

• Journal of Korea Water Resources Association
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• v.35 no.5
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• pp.485-500
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• 2002

Hydraulic model was developed to analyze the complex flow due to channel structures, tide, and tributaries in the lower Han river and Imjin river. DWOPER-2K model which can automatically process the data transformation in the model was developed as the 1-D hydraulic routing model. Observed data in tidal zone and the recent channel geometry data were collected for hydraulic model. And the flow over the Jamsil and Singok submerged weir was analyzed properly and roughness coefficient was optimized to each regions and each discharges. By the results of verification of the model, the model developed in this study may contribute to improvement of the accuracy of flood forecasting and channel management because this model can efficiently and properly analyze the various kind of flow occurred in the region of the lower Han river and Imjin river.

• Journal of the Korean Institute of Intelligent Systems
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• v.21 no.2
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• pp.224-229
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• 2011

Collaborative filtering is used the most for recommendation systems because it can recommend potential items. However, when there are not many items to be evaluated, collaborative filtering can be subject to the influence of similarity or preference depending on the situation or the whim of the evaluator. In addition, by recommending items only on the basis of similarity with items that have been evaluated previously without relation to the present situation of the user, the recommendations become less accurate. In this paper, in order to solve the above problems, before starting the collaborative filtering procedure, we calculated similarity not by comparing all the values evaluated by users but rather by comparing only those users who were above the average in order to improve the accuracy of the recommendations. In addition, in the ceaselessly changing ubiquitous computing environment, it is not proper to recommend service information based only on the items evaluated by users. Therefore, we used methods of calculating similarity wherein the users' real time context information was used and a high weight was assigned to similar users. Such methods improved the recommendation accuracy by 16.2% on average.