• Journal of Information Technology Services
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• v.7 no.2
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• pp.59-75
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• 2008

Despite our extensive understanding on the Internet business and widely understood first-mover advantage. it is not clearly answered yet whether an internet firm can enjoy the first-mover advantage in the new environment of the Internet. This is mainly because the Internet marketplace itself has a complex combination of various business models, ranging from a simple channel-extension to a whole new business model. Based on new theoretical development on the first-mover advantage, we empirically test whether being an early mover in the Internet environment materially affects firm performance, using clickstream data from Korea where broadband Internet installation is ranked as top among OECD countries. Our results show the effectiveness of first-mover advantage on the web does not exist, regardless of its business model and competitive environment. This result expands our understandings on the e-business, not to mention of the real feature of first-mover advantage.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.529-531
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• 2005

이 논문에서는 용어 클러스터링의 성능에 직접적인 영향을 주는 자질 확장에 따른 시스템의 성능 변화를 보았다. 객관적인 성능 비교를 위하여 용어 클러스터링 결과와 한국어 의미 계층망에서 추출한 클러스터를 비교하였다. 실험 결과, 용어의 뜻 풀이말을 자질로 사용한 경우보다 자질을 확장한 방법(Bigram, Case)이 성능이 좋게 나왔으며, 자질확장 시에 사용되는 말뭉치의 추출방법에 따라 다른 성능을 보였는데, 단순히 Bigram 정보를 사용하여 확장한 것 보다는 동사의 격 관계(Case)정보를 이용한 것이 성능이 좋게 나왔다.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.575-581
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• 1999

Yielding is an important feature of the stress-strain behavior of clays. This study was performed to estabilish the yielding curves and properties for a marine caly from Jangheung. Chonnam Province . A series of tests was done by means of the various stress path tests. Results of the tests are as follows ; 1) The laboratory -determined Ko is very similar to that applied to the Jaky equation. 2) The shape of yielding curve is nealry symmetrical about the p' axis like other natural clays. 3) The critical state parameters, Mc and Me are the same for compression and extension tests which contrasts with the results of the isotropically consolidated soils. 4) The state boundary suface using the critical state paratmers can resresent the normalized yielding curve obtained by various stress path experiments.

• Proceedings of the IEEK Conference
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• summer
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• pp.376-381
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• 2004

The Semantic Web is an extension of the current Web in which information is given formal and explicit meaning. The Semantic Web enables computer programs to understand information contents and thus facilitates more efficient discovery, automation, integration and sharing of data. To create Semantic Web contents one needs appropriate tools. In this paper, we describe such a toolkit we have constructed. The most important feature of the toolkit is that it makes use of information extraction techniques for automatically annotating web page contents. Experiments with a real life application show promising results and demonstrate the usefulness of the toolkit.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.781-784
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• 2014

Face recognition under controlled settings, such as limited viewpoint and illumination change, can achieve good performance nowadays. However, real world application for face recognition is still challenging. In this paper, we use Affine SIFT to detect affine invariant local descriptors for face recognition under large viewpoint change. Affine SIFT is an extension of SIFT algorithm. SIFT algorithm is scale and rotation invariant, which is powerful for small viewpoint changes in face recognition, but it fails when large viewpoint change exists. In our scheme, Affine SIFT is used for both gallery face and probe face, which generates a series of different viewpoints using affine transformation. Therefore, Affine SIFT allows viewpoint difference between gallery face and probe face. Experiment results show our framework achieves better recognition accuracy than SIFT algorithm on FERET database.

• Journal of the Semiconductor & Display Technology
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• v.8 no.3
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• pp.39-44
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• 2009

Local Binary Pattern (LBP) is becoming a popular tool for various machine vision applications such as face recognition, classification and background subtraction. In this paper, we propose a new extension of LBP, called the Diagonal LBP (DLBP), to handle the image-based gender classification problem arise in interactive display systems. Instead of comparing neighbor pixels with the center pixel, DLBP generates codes by comparing a neighbor pixel with the diagonal pixel (the neighbor pixel in the opposite side). It can reduce by half the code length of LBP and consequently, can improve the computation complexity. The Support Vector Machine is utilized as the gender classifier, and the texture profile based on DLBP is adopted as the feature vector. Experimental results revealed that our approach based on the diagonal LPB is very efficient and can be utilized in various real-time pattern classification applications.

• Journal of Agricultural Extension & Community Development
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• v.21 no.4
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• pp.1029-1060
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• 2014

The purpose of this study are to figure out whether there are the meaningful differences between learner's learning achievements and contents preference in accordance with the delivery strategies (instructor-focused model, learner-focused model) of learning materials suggested by Bloom in web-based instruction, and to suggest the various options on the contents delivery strategies to improve the learner's learning achievements of each learning domains. Learning domains were divided by the cognitive domain, the affective domain, and the psychomotor domain. The result of research with 182 learners showed that learner-focused model in the cognitive domain caused higher learning achievements and preference than instructor-focused model. And instructor-focused model in the psychomotor domain compared with learner-focused model caused higher learning achievements and preference. However, there were less meaningful differences in the affective domain. In other words, learner-focused model is appropriate to the feature of the cognitive domain while instructor-focused model is appropriate to the feature of the psychomotor domain. The results suggest that delivery strategies should be chosen by domains of learning contents in order to improve learner's learning achievements in web-based instruction. Learner-focused delivery strategies in the cognitive domain and instructor-focused delivery strategies in the psychomotor domain need to be considered positively. Delivery strategies should be studied and developed in order to lead higher learning achievements and preference.

• The Journal of Korean Academy of Prosthodontics
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• v.17 no.1
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• pp.35-46
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• 1979

A number of experimental studies have been carried out in order to clarify the question as to how temporomandibular joint adapt to the changes of mandibular movement and occlusal equilibration. Recently, the studies on the interrelations between anatomical structure of temporomandibular joint and the state of occlusion have been actively performed in dentistry particularly in prosthodontic field. Author performed extraction of unilateral mandibular molars in 30 mature male rats, and observed histological changes of temporomandibular joint through the light microscope. Following results were obtained. 1. The loss of unilateral teeth gave rise to the changes in the location of condylar head, that is, interior displacement of condylar head in the extraction side and upper displacement in the non-extraction side. 2. Articular disk was compressed by the interior surface of condylar head, resulting in its extension below the condylar neck in the extraction side, and the histological arrangement of the compressed area showed irregular feature. 3. The extension of articular disk below the condylar neck was accompanied with the contraction of muscle fibers which were originated from the articular disk. 4. The cartilage layer of articular fossa to the exterior of the extraction side showed hypertropy. 5. Early in the experiment, the inernal extremity of condylar head of extract ion side showed bone resorption, and cartilage layer of condylar head showed hypertropy. At 12 weeks after experiment, the condylar surface showed flattened, and the cartilage layer of condylar head was replaced by the compact bone. 6. The articular disk showed the formation of pannus in the extraction side as well as in the non-extraction side. 7. The occlusal disturbance due to unilateral missing teeth has brought about the non-inflammatory retrogressive change and osteoarthrotic change late in the experiment.

• Journal of Agricultural Extension & Community Development
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• v.24 no.4
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• pp.249-264
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• 2017

Modeling the consumer demand of fresh meat requires its distinct feature which other types of food product does not have. Most of the fresh meat products are likely to be unbranded, bought on a weight basis and affected by macro shocks such as seasonality, holiday effect and the disease incidence. Furthermore, consumers tend to purchase multiple categories of fresh meat in a week. Therefore, we apply a multiple discrete/continuous model on fresh meat consumption data to study the effect of macro shocks on fresh meat sales as well as of price change. As a result shows, Each fresh meat is relatively more likely to be bought in peak season of each fresh meat compared with imported pork which is set as a 'reference category' in this analysis. For clarity of the effect of disease incidence, we perform further analysis regarding the effect of livestock disease on fresh meat purchase probability. It shows that the avian flu in 2014 has strong negative impact on the purchase probability of chicken and the foot-and-mouth disease has negative impact on the purchase probability of pork and beef for part of outbreak periods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.7
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• pp.105-112
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• 2002

An experimental study of the vortical flow characteristics around a yawed delta wing with the leading edge extension at high incidence angle is undertaken by upper surface pressure measurements. A special emphasis has been put on analyzing the basic physics of vortical flows, concerning the effects of incidence and sideslip angle on the aerodynamic characteristics of the wing, especially under high angle of attack. The experimental data has been dearly demonstrated the beneficial effect of the LEX vortex on the wing vortex. It leads to an essential stabilization of the wing vortex against its breakdown until at much higher incidence angle under small sideslip. An interesting flow feature is occurrence of the rolling moment reversal at a certain range of angle of attack and sideslip angle.