• Journal for History of Mathematics
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• v.27 no.1
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• pp.59-66
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• 2014

This interdisciplinary study explores G$\ddot{o}$del's hermeneutics of the relationship between relativity theory and idealistic philosophy in terms of time. For G$\ddot{o}$del, Einstein's contribution to the physical realization of idealistic philosophy would be remarkable. We start with a historical background around G$\ddot{o}$del's paper for Einstein(1949a). From the perspective of G$\ddot{o}$del's cosmology, the second part addresses the relative nature of time, and the next then investigates the rotating model of universes. G$\ddot{o}$del's own results show that the temporal conditions of relativity and idealistic philosophy are satisfiable in the mathematical model of rotating universes. Thus, it could be asserted to travel into any region of the past, present or future, and back again.

• Knowledge Management Research
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• v.11 no.2
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• pp.17-35
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• 2010

As the internet has been used widely, many online communities have been appeared. Initially, many users used online communities for communication and information sharing. Recently, users start using online communities for building, maintaining, and extending social networks which they did in offline environments previously. The importance of online community is considered by many scholars and also companies to use it strategically. Therefore many studies have focused on exploring characteristics of online communities. Most of them have emphasized the importance of online community. Few study focuses on dynamics within online community. By using social network analysis (SNA), this study tries to explore dynamics of online community. Specially, By measuring the centrality of online community and tracing its changes, this study investigates how the relationships among participants in online communities have been changed over the time. Findings of this study indicate that, as participants has joined in an online community over the time, an opinion leader is appeared, and her/his power is changed.

• ETRI Journal
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• v.35 no.6
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• pp.1029-1037
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• 2013

This paper introduces a novel and fast synthesizing method for 3D motions of quadrupedal animals that uses only a small set of motion capture data. Unlike human motions, animal motions are relatively difficult to capture. Also, it is a challenge to synthesize continuously changing animal motions in real time because animals have various gait types according to their speed. The algorithm proposed herein, however, is able to synthesize continuously varying motions with proper limb configuration by using only one single cyclic animal motion per gait type based on the biologically driven Froude number. During the synthesis process, each gait type is automatically determined by its speed parameter, and the transition motions, which have not been entered as input, are synthesized accordingly by the optimized asynchronous motion blending technique. At the start time, given the user's control input, the motion path and spinal joints for turning are adjusted first and then the motion is stitched at any speed with proper transition motions to synthesize a long stream of motions.

• The Journal of the Korean dental association
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• v.22 no.12 s.187
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• pp.1067-1073
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• 1984

In the treatment of functional orthodontic problems, timing is not an issue. All orthodontists start as soon as the condition is recognized. However, there is an active dialogue concerning treatment timing for structure problems. The major points in contention center around the operator's ability is to control the growth of the facial bones and to maintain post-treatment tooth position through the maturation period (especially when this position was gained by techniques involving arch expansion or distal driving of posterior segments). Factors taken into account to determine the best time of orthodontic treatment include diagnosis, interception, growth rate, patient cooperation, eruptive state and treatment period. With those exceptions of all functional problems, mild dental discrepancies and skeletal deficiencies with a predictably excellent growth potential (early treatment), the period immediately following the eruption of the permanent second molars is the period during which most orthodontic treatment should be initiated. At this time the full volume of tooth substances is present, the individual growth pattern in well established, there are sufficient teeth to receive nearly any type of appliances and the patient can easily tolerate the wearing of appliances.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.96.6-96
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• 2001

A high peak power demand at substations will result under Moving Block Signalling (MBS) when a dense queue of trains begins to start from a complete stop at the same time in an electrified railway system. This may cause the power supply interruption and in turn affect the train service substantially. In a recent study, measures of Starting Time Delay (STD) and Acceleration Rate Limit (ARL) are the possible approaches to reduce the peak power demand on the supply system under MBS. Nevertheless, there is no well-defined relationship between the two measures and peak power demand reduction (PDR). In order to attain a lower peak demand at substations on different traffic conditions and system requirements, an expert system is one of the possible approaches to procure the appropriate use of peak demand reduction measures ...

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.3
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• pp.76-82
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• 1999

This study was carried out to verify finding performance of dental diamond bur and investigate the possibility of AE application in density field. Work pieces were made of acryl and bovine respectively for the experiments in this study. Grinding test was conducted to get the data of grinding resistance and specific finding energy of low different types of diamond bur by using tool dynamometer. AE signal was acquired to verify grinding process in the AE measuring system. AErms value was increased as the grinding velocity and depth were increasing, but it decreased as the feed rate was increasing. The case of the small value of AE signal is due to abnormal grinding in D type diamond bur. By analyzing AErms start and finish time of grinding working, abnormal grinding state can be confined. Abnormal state can be found through the behavior of AE signal in the finding working. As a result, it is expected that forecast of abnormal state is possible using AE equipments under real time process.

• Elastomers and Composites
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• v.50 no.1
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• pp.13-17
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• 2015

A study of the effects of MWCNT as a nucleating agent on the formation reactions of the rigid polyurethane foams (RPUFs) was carried out. Sample PUFs, formulated with grease-type master batch of MWCNT/surfactant, were fabricated by free-rising method. Temperature changes with time during foaming process were measured using a digital thermometer. RPUF foaming process was observed to undergo 2-step processes with temperature inflection around 60 sec after the start of reaction, and then reached slowly the max. temperature. While the max. temperature of neat PUF was measured as ca. $120^{\circ}C$, that of the samples with MWCNT were as higher value as ca. $130^{\circ}C$, and, even the time to reach that temperature was reduced by about 15 sec. Average cell size of PUF samples decreased from 185.1 for the neat PUF to $162.9{\mu}m$ for the sample of 0.01 phr of MWCNT. As the result, it was considered that MWCNT in RPUF foaming process could play a roll both as a nucleating agent and as a catalyst.

• Proceedings of the KSPS conference
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• 2006.05a
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• pp.89-93
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• 2006

This paper presents ETRI broadcast news speech recognition system. There are two major issues on the broadcast news speech recognition: 1) real-time processing and 2) out-of-vocabulary handling. For real-time processing, we devised the dual decoder architecture. The input speech signal is segmented based on the long-pause between utterances, and each decoder processes the speech segment alternatively. One decoder can start to recognize the current speech segment without waiting for the other decoder to recognize the previous speech segment completely. Thus, the processing delay is not accumulated. For out-of-vocabulary handling, we updated both the vocabulary and the language model, based on the recent news articles on the internet. By updating the language model as well as the vocabulary, we can improve the performance up to 17.2% ERR.

• Korean Management Science Review
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• v.32 no.3
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• pp.91-103
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• 2015

This study recognizes that there is a correlation between the movement of the financial market and the sentimental changes of the public participating directly or indirectly in the market, and applies the relationship to investment strategies for stock market. The concerns that market participants have about the economy can be transformed to the search terms that internet users query on search engines, and search volume of a specific term over time can be understood as the economic trend of big data. Under the hypothesis that the time when the economic concerns start increasing precedes the decline in the stock market price and vice versa, this study proposes three investment strategies using casuality between price of domestic stock market and search volume from Naver trends, and verifies the hypothesis. The computational results illustrate the potential that combining extensive behavioral data sets offers for a better understanding of collective human behavior in domestic stock market.

• Journal of the Korean Operations Research and Management Science Society
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• v.27 no.2
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• pp.97-109
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• 2002

Manufacturing environments in the real world are subject to many sources of change and uncertainty, such as new job releases, job cancellations, a chance in the processing time or start time of some operation. Thus, the realistic scheduling method should Properly reflect these dynamic environment. Based on the release times of jobs, JSSP (Job Shoe Scheduling Problem) can be classified as static and dynamic scheduling problem. In this research, we mainly consider the dynamic JSSP with continually arriving jobs. The goal of this research is to develop an efficient scheduling method based on GA (Genetic Algorithm) to address dynamic JSSP. we designed scheduling method based on SGA (Sing1e Genetic Algorithm) and PGA (Parallel Genetic Algorithm) The scheduling method based on GA is extended to address dynamic JSSP. Then, This algorithms are tested for scheduling and rescheduling in dynamic JSSP. The results is compared with dispatching rule. In comparison to dispatching rule, the GA approach produces better scheduling performance.