• Korean Journal of Ichthyology
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• v.24 no.2
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• pp.84-93
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• 2012

Fish species composition and abundance in the waters of nearby Nakdong River estuary were investigated non-continuously and seasonally by shrimp beam trawl in summer 2007, winter 2009, and from spring 2010 to autumn 2010. During the study period, total fish species were collected 92 species, 36 families in study area. Shannon index was 1.893~2.962, and evenness was 0.050~0.231. Fish species composition was shown interannually and seasonally variations in the waters of nearby Nakdong River estuary. We carryed out cluster analysis to contain the data in previous and current study. Fish species composition was divided 3 groups which were 1987~1988 and 1998, 2001~2002, and 2007~2008 and 2009~2010. Average and minimum length in this study was longer than its in previous studies, and length range in this study was wider than its in previous studies, too. Dominant fish increased individuals and weight per unit area in this study. Especially Lophius litulon, Raja kenojei, Eopsetta grigorjewi, and Zeus faber were much better than past 2002. Liparis tanakai, Repomucenus valenciennei and Leiognathus nuchalis were dominant fish in previous study, but those decreased individuals and weight per unit area in this study.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1705-1711
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• 1991

On-line fault detection and diagnosis has an increasing interest in a chemical process industry, especially for a process control and automation. The chemical process needs an intelligent operation-aided workstation which can do such tasks as process monitoring, fault detection, fault diagnosis and action guidance in semiautomatic mode. These tasks can increase the performance of a process operation and give merits in economics, safety and reliability. Aiming these tasks, series of researches have been done in our lab. Main results from these researches are building appropriate knowledge representation models and a diagnosis mechanism for fault detection and diagnosis in a chemical process. The knowledge representation schemes developed in our previous research, the symptom tree model and the fault-consequence digraph, showed the effectiveness and the usefulness in a real-time application, of the process diagnosis, especially in large and complex plants. However in our previous approach, the diagnosis speed is its demerit in spite of its merits of high resolution, mainly due to using two knowledge models complementarily. In our current study, new knowledge representation scheme is developed which integrates the previous two knowledge models, the symptom tree and the fault-consequence digraph, into one. This new model is constructed using a material balance, energy balance, momentum balance and equipment constraints. Controller related constraints are included in this new model, which possesses merits of the two previous models. This new integrated model will be tested and verified by the real-time application in a BTX process or a crude unit process. The reliability and flexibility will be greatly enhanced compared to the previous model in spite of the low diagnosis speed. Nexpert Object for the expert system shell and SUN4 workstation for the hardware platform are used. TCP/IP for a communication protocol and interfacing to a dynamic simulator, SPEEDUP, for a dynamic data generation are being studied.

• Journal of Information Technology Applications and Management
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• v.21 no.4
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• pp.203-223
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• 2014

This study proposes a novel context-aware recommender system, which is designed to recommend the items according to the customer's responses to the previously recommended item. In specific, our proposed system predicts the user's emotional state from his or her responses (such as facial expressions and movements) to the previous recommended item, and then it recommends the items that are similar to the previous one when his or her emotional state is estimated as positive. If the customer's emotional state on the previously recommended item is regarded as negative, the system recommends the items that have characteristics opposite to the previous item. Our proposed system consists of two sub modules-(1) emotion prediction module, and (2) responsive recommendation module. Emotion prediction module contains the emotion prediction model that predicts a customer's arousal level-a physiological and psychological state of being awake or reactive to stimuli-using the customer's reaction data including facial expressions and body movements, which can be measured using Microsoft's Kinect Sensor. Responsive recommendation module generates a recommendation list by using the results from the first module-emotion prediction module. If a customer shows a high level of arousal on the previously recommended item, the module recommends the items that are most similar to the previous item. Otherwise, it recommends the items that are most dissimilar to the previous one. In order to validate the performance and usefulness of the proposed recommender system, we conducted empirical validation. In total, 30 undergraduate students participated in the experiment. We used 100 trailers of Korean movies that had been released from 2009 to 2012 as the items for recommendation. For the experiment, we manually constructed Korean movie trailer DB which contains the fields such as release date, genre, director, writer, and actors. In order to check if the recommendation using customers' responses outperforms the recommendation using their demographic information, we compared them. The performance of the recommendation was measured using two metrics-satisfaction and arousal levels. Experimental results showed that the recommendation using customers' responses (i.e. our proposed system) outperformed the recommendation using their demographic information with statistical significance.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1421-1428
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• 2013

In this paper, we would like to test whether the hit at a particular bat has a dependency with the hitting results at the previous bats in professional baseball games. For this purpose, we used the 2011 Korean Baseball League data. We find out that the hitting percentage at a particular bat has no dependency with the hit at the previous bat, after reviewing the conditional probability of hit at each bat and the lift. From the independence test of hits at consecutive bats, and hit at a particular bat with no hits at previous bats, we can conclude that hits at particular bats are not dependent on the hits at previous bats in most cases. Hence, we can safely conclude that a hit at a particular bat is statistically independent from the hits at the previous bats.

• Journal of Korean Foot and Ankle Society
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• v.10 no.2
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• pp.163-167
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• 2006

Purpose: To evaluate the results of extracorporeal shock wave therapy (ESWT) for patients with chronic proximal plantar fascitis. Materials and Methods: Between April 2005 and April 2006, 35 cases (24 patients) who were followed more than 6 months were evaluated. By $EvoTron^{(R)}$, 2 sessions of ESWT (Group 1: 1200 and Group 2: 1500 shock waves / session of $0.12\;mJ/mm^2$) were performed at 2 weeks interval. The mean age was 40.0 (range, 15-59) years. 13 patients were male and 11 patients were female. Visual analogue scale (VAS) on daily activity and a 100-point scoring system including 70 points for pain and 30 points for function were used. The clinical outcomes were rated as follows: excellent, no pain on daily activity; good, less than 50% of previous VAS; fair, 50-75% of previous VAS; or poor, more than 75% of previous VAS. Excellent and good were graded as satisfactory results. We compare clinical results between groups and evaluate the relationships between clinical results and duration of symptom, fascial thickening and previous steroid injection were evaluated. Results: Overall satisfactory rate were 71.4%. There was no significant difference of clinical results between groups. And there were no significant difference between clinical results and duration of symtom, preoperative fascial thickening and previous steroid injection. Conclusions: ESWT for recalcitrant chronic proximal plantar fascitis is useful treatment method with high patient satisfaction and pain relief, but more long-term study must be needed.

• Journal of Gastric Cancer
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• v.21 no.2
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• pp.203-212
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• 2021

Purpose: The impact of the interval between previous endoscopy and diagnosis on the treatment modality or mortality of undifferentiated (UD)-type gastric cancer is unclear. This study aimed to investigate the effect of endoscopic screening interval on the stage, cancer-related mortality, and treatment methods of UD-type gastric cancer. Materials and Methods: We reviewed the medical records of newly diagnosed patients with UD gastric cancer in 2013, in whom the interval between previous endoscopy and diagnosis could be determined. The patients were classified into different groups according to the period from the previous endoscopy to diagnosis (<12 months, 12-23 months, 24-35 months, ≥36 months, and no history of endoscopy), and the outcomes were compared between the groups. In addition, patients who underwent endoscopic and surgical treatment were reclassified based on the final treatment results. Results: The number of enrolled patients was 440, with males representing 64.1% of the study population; 11.8% of the participants reported that they had undergone endoscopy for the first time in their cancer diagnosis. The percentage of stage I cancer at diagnosis significantly decreased as the interval from the previous endoscopy to diagnosis increased (65.4%, 63.2%, 64.2%, 45.9%, and 35.2% for intervals of <12 months, 12-23 months, 24-35 months, ≥36 months, and no previous endoscopy, respectively, P<0.01). Cancer-related mortality was significantly lower for a 3-year interval of endoscopy (P<0.001). Conclusions: A 3-year interval of endoscopic screening reduces gastric-cancer-related mortality, particularly in cases of UD histology.

• Knowledge Management Research
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• v.18 no.2
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• pp.103-127
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• 2017

This study examines the effects of failed airline services on the consumers' psychological process and their behavioral responses. Having different classifications from the previous studies, this study focuses on dividing important factors of airline services into search attributes(e.g. sale and procedure services, services concerning flight attendant, in-flight services) and experience attributes(e.g. flight services, collateral services). Using structural equation modeling, this study shows that the failure of service factors of the experience attributes provokes the feeling of disappointment with mediation effect of external attribution while the failure of service factors of search attributes provokes the feeling of regret with mediation effect of internal attribution. Finally, disappointment leads to consumers' complaint behavior while regret leads to consumers' switching behavior. Unlike previous studies, we show that when a service failure occurs, depending on each attribute, consumers feel negative emotions of disappointment or regret through different attribution processes and finally show different behavioral responses with an empirical analysis.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.5
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• pp.352-359
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• 2016

The soft keyboard with touch interaction is universally available on mobile phone, a variety of previous studies with respect to the soft keyboard on smart devices had been conducted. However, previous studies of cursor control for text entry on smart devices such as smartphone did not performed. In this study, we compared three types of cursor controls (Default, 3D touch, Slide) in smartphone using Fitts' law and C-D ratio. Then we performed a laboratory experiment with three cursor control types and evaluated using cursor movement time as a quantitative evaluation and 8 subjective metrics for usability as a qualitative evaluation. Then, we discussed what types of cursor control showed better performance and subjective satisfaction through their results. From these results, this study recommended the design guidelines for cursor control on smartphones and developed its study methods as our contributions.

• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.111-116
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• 2006

The purpose of this study is to investigate the relations between unbonded tendon stress and its influential parameters, i.e. bonded reinforcement ratio, span/depth ratio, and loading type. To this end, the influence of such parameters was examined with twenty eight test results of previous studies. Afterwards, an experimental study was carried out with twenty one test specimens. The investigation of previous and current experiments revealed the followings; (1) The bonded reinforcement ratio and prestressing ratio were proved to be important variables on the unbonded tendon stress. (2) The ratio of span to depth and the type of loading affected the unbonded tendon stress partially although their effects varied with bonded reinforcement ratio. (3) AASHTO LRFD Code and Moon/Lim's design equations predicted the experimental results well with the safety margin.

• Journal of Information Technology Services
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• v.12 no.1
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• pp.99-113
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• 2013

In spite of IT performance can be achieved through the interaction of IT and organization, many previous study has been treated the introduction of the information system itself as a final outcome. But if it doesn't clear about understanding on IT performance, performance management is difficult and also it is impossible to produce the intended outcomes. This study investigates the improvement of the business performance of SMEs through IT investment, whether the investment process on business performance. Analytical methods that were used in previous studies were maintained and new model IO(Information Orientation) analysis was applied. Therefore, this study is meaningful to establish a new methodology, that is not attempted until now, for evaluating the performance of IT investment, and analysis relationship between IT investment and business performance.