• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.4
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• pp.295-307
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• 2006

Styela clava, called non-native tunicate or sea squirt, is habitat which include bays and harbors in Korea and several sites in the sea faced world. We fabricate cellulose membrane nerve conduit (CMNC) from this native sea squirt skin, and evaluate the capacity of promoting peripheral nerve regeneration in the rat sciatic nerve defect model. After processing the pure cellulose membrane from the sea squirt skin as we already published before, CMNC was designed as a non-tubular sheet with 14 mm length and 4 mm width. Total eleven male Spraque-Dawley rats (12 weeks, weighing 250 to 300g) were divided into sham group (n=2), silicone tube grafted control group (n=3) and experimental group (n=6). Each CMNC grafted nerve was evaluated after 4, 8 and 12 weeks in the experimental group, and after 12 weeks, sciatic function was evaluated with sciatic function index (SFI) and gait analysis, and histomorphology of nerve conduit and the innervated tissues of sciatic nerve were all examined using image analyzer and electromicroscopic methods in the all groups. The regenerated axon and nerve sheath were found only in the inner surface of the CMNC after 4 weeks and became more thicker after 8 and 12 weeks. In the TEM study, CMNC grafted group showed more abundant organized myelinated nerve fibers with thickened extracellular matrix than silicone conduit grafted group after 12 weeks. The sciatic function index (SFI) and ankle stance angle (ASA) in the functional evaluation were $-47.2{\pm}3.9$, $35.5^{\circ}{\pm}4.9^{\circ}$ in CMNC grafted group (n=2) and $-80.4{\pm}7.4$, $29.2^{\circ}{\pm}5.3^{\circ}$ in silicone conduit grafted group (n=3), respectively. And the myelinated axon was 41.59% in CMNC group and 9.51% in silicone conduit group to the sham group. The development of a bioactive CMNC to replace autogenous nerve grafts offers a potential and available approach to improved peripheral nerve regeneration. As we already published before, small peptide fragment derived from the basement membrane matrix proteins of squirt skin, which is a kind of anchoring protein composed of glycocalyx, induced the effective axonal regeneration with rapid growth of Schwann cells beneath the inner surface of CMNC. So the possibilities of clinical application as a peripheral nerve regeneration will be able to be suggested.

• (The)Study of the Eastern Classic
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• no.41
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• pp.477-516
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• 2010

The Korean art history academia has lately been carrying out active research on the Korean art market and art collectors. This area of research is significant in that it attempts to overcome the limitations of previous research trends focused on tracing back and analyzing preeminent masters, their schools and their influence, and approach new subject matters such as art and society, circulation and consumption of art works, which were unapproachable with previous research methods. This paper examines the life, artwork and art collection activities of Songeun(松隱) Yi Byeong-jik(李秉直: 1896-1973), an outstanding painter, calligrapher and art collector during the Japanese colonial period. The primary purpose of this paper is to advance the research project the author has recently initiated on modern Korean art collectors by reconstructing parts of this major art collector's individual lifestyle and to generally identify the art collection activities and the art works that he kept. Yi Byeong-jik, one of the preeminent art collectors during the colonial period, disposed his voluminous collection through two auctions in 1937 and 1941, and then held another auction two weeks before the onset of the Korean War on June 25, 1950 to sell off the remaining works. It seems that the reason why Yi had auctioned off his collections was for the purpose of investing in education. The tale that Yi safely kept 'Sam-guk-yu-sa(三國遺事),' which is considered a national treasure, even through the time of turbulence is evidence of his exemplary behavior as a model art collector. He may be one of the best examples of what an art collector should be in terms of giving back to the society and preserving things of beauty and value. However, one factor that limited and defined Yi's life was that he was a eunuch. This aspect of his life could be pointed out as the biggest factor that stopped him from becoming a mainstream participant in the art world despite his influence as a great painter, calligrapher, significant art collector, and discerning connoisseur.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1069-1080
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• 2022

The tropospheric ozone is a pollutant that causes a great deal of damage to humans and ecosystems worldwide. In the event that ozone moves downwind from its source, a localized problem becomes a regional and global problem. To enhance ozone monitoring efficiency, geostationary satellites with continuous diurnal observations have been developed. The objective of this study is to derive the Tropospheric Ozone Movement Vector (TOMV) by employing continuous observations of tropospheric ozone from geostationary satellites for the first time in the world. In the absence of Geostationary Environmental Monitoring Satellite (GEMS) tropospheric ozone observation data, the GEOS-Chem model calculated values were used as synthetic data. Comparing TOMV with GEOS-Chem, the TOMV algorithm overestimated wind speed, but it correctly calculated wind direction represented by pollution movement. The ozone influx can also be calculated using the calculated ozone movement speed and direction multiplied by the observed ozone concentration. As an alternative to a backward trajectory method, this approach will provide better forecasting and analysis by monitoring tropospheric ozone inflow characteristics on a continuous basis. However, if the boundary of the ozone distribution is unclear, motion detection may not be accurate. In spite of this, the TOMV method may prove useful for monitoring and forecasting pollution based on geostationary environmental satellites in the future.

• Information Systems Review
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• v.25 no.1
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• pp.129-143
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• 2023

In the era of big data, the field of artificial intelligence is showing remarkable growth, and in particular, the image classification learning methods by deep learning are becoming an important area. Various studies have been actively conducted to further improve the performance of CNNs, which have been widely used in image classification, among which a representative method is the Convolutional Recurrent Neural Network (CRNN) algorithm. The CRNN algorithm consists of a combination of CNN for image classification and RNNs for recognizing time series elements. However, since the inputs used in the RNN area of CRNN are the flatten values extracted by applying the convolution and pooling technique to the image, pixel values in the same phase in the image appear in different order. And this makes it difficult to properly learn the sequence of arrangements in the image intended by the RNN. Therefore, this study aims to improve image classification performance by proposing a novel hybrid method of CNN and RNN applying the concepts of encoder and decoder. In this study, the effectiveness of the new hybrid method was verified through various experiments. This study has academic implications in that it broadens the applicability of encoder and decoder concepts, and the proposed method has advantages in terms of model learning time and infrastructure construction costs as it does not significantly increase complexity compared to conventional hybrid methods. In addition, this study has practical implications in that it presents the possibility of improving the quality of services provided in various fields that require accurate image classification.

• Steel and Composite Structures
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• v.50 no.6
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• pp.705-720
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• 2024

Analyzing the collapse behavior of thin-walled steel structures holds significant importance in ensuring their safety and longevity. Geometric imperfections present on the surface of metal materials can diminish both the durability and mechanical integrity of steel shells. These imperfections, encompassing local geometric irregularities and deformations such as holes, cavities, notches, and cracks localized in specific regions of the shell surface, play a pivotal role in the assessment. They can induce stress concentration within the structure, thereby influencing its susceptibility to buckling. The intricate relationship between the buckling behavior of these structures and such imperfections is multifaceted, contingent upon a variety of factors. The buckling analysis of thin-walled steel shell structures, similar to other steel structures, commonly involves the determination of crucial material properties, including elastic modulus, shear modulus, tensile strength, and fracture toughness. An established method involves the emulation of distributed geometric imperfections, utilizing real test specimen data as a basis. This approach allows for the accurate representation and assessment of the diversity and distribution of imperfections encountered in real-world scenarios. Utilizing defect data obtained from actual test samples enhances the model's realism and applicability. The sizes and configurations of these defects are employed as inputs in the modeling process, aiding in the prediction of structural behavior. It's worth noting that there is a dearth of experimental studies addressing the influence of geometric defects on the buckling behavior of cylindrical steel shells. In this particular study, samples featuring geometric imperfections were subjected to experimental buckling tests. These same samples were also modeled using Finite Element Analysis (FEM), with results corroborating the experimental findings. Furthermore, the initial geometrical imperfections were measured using digital image correlation (DIC) techniques. In this way, the response of the test specimens can be estimated accurately by applying the initial imperfections to FE models. After validation of the test results with FEA, a numerical parametric study was conducted to develop more generalized design recommendations for the stainless-steel shell structures with the initial geometric imperfection. While the load-carrying capacity of samples with perfect surfaces was up to 140 kN, the load-carrying capacity of samples with 4 mm defects was around 130 kN. Likewise, while the load carrying capacity of samples with 10 mm defects was around 125 kN, the load carrying capacity of samples with 14 mm defects was measured around 120 kN.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1463-1478
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• 2022

Maritime transport accounts for 99.7% of the exports and imports of the Republic of Korea; therefore, developing a vessel monitoring system for efficient operation is of significant interest. Several studies have focused on tracking and monitoring vessel movements based on automatic identification system (AIS) data; however, ships without AIS have limited monitoring and tracking ability. High-resolution optical satellite images can provide the missing layer of information in AIS-based monitoring systems because they can identify non-AIS vessels and small ships over a wide range. Therefore, it is necessary to investigate vessel monitoring and small vessel classification systems using high-resolution optical satellite images. This study examined the possibility of developing ship monitoring systems using Compact Advanced Satellite 500-1 (CAS500-1) satellite images by first training a deep learning model using satellite image data and then performing detection in other images. To determine the effectiveness of the proposed method, the learning data was acquired from ships in the Yellow Sea and its major ports, and the detection model was established using the You Only Look Once (YOLO) algorithm. The ship detection performance was evaluated for a domestic and an international port. The results obtained using the detection model in ships in the anchorage and berth areas were compared with the ship classification information obtained using AIS, and an accuracy of 85.5% and 70% was achieved using domestic and international classification models, respectively. The results indicate that high-resolution satellite images can be used in mooring ships for vessel monitoring. The developed approach can potentially be used in vessel tracking and monitoring systems at major ports around the world if the accuracy of the detection model is improved through continuous learning data construction.

• International Commerce and Information Review
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• v.13 no.3
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• pp.3-29
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• 2011

The Internet has become a medium through which people engage in increasingly sophisticated transactions. Businesses and consumers now use the Internet to communicate and engage in commercial transactions creating a virtual worldwide marketplace. They fear that the determination of Internet jurisdiction could be uncertain because electronic commerce is not executed in one particular place. Until now, there are no specific rules in the model laws and conventions dealing with international jurisdiction in electronic commerce. Due to the fact that U.S. companies are at the forefront of Internet technology, litigation regarding electronic commerce in the U.S. is more advanced than anywhere else in the world This paper analysis the basic framework for personal jurisdiction and approach for determining international jurisdiction in electronic commerce cases and explain the differences of several approaches involving interactions over the Internet. According to jurisdiction approach test, the U.S. employs sliding scale, effects and targeting test in electronic commerce. In recent many research views the targeting test as a global standard for determining international electronic commerce jurisdiction. However, there is still no clear indication of conclusive test of jurisdiction determination for electronic commerce. Therefore, it is a changing and process of jurisdiction test in the U.S. cases. In Korea, there is jurisdiction related clause in Private International Law, but it may be asked whether applicable in electronic commerce. Accordingly, analysis of the precedents changing related to electronic commerce jurisdiction of U.s. is full of suggestions in Korean companies, consumers and helps an enactment of code of civil procedure that containing many group's demands.

• Sim-seong Yeon-gu
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• v.28 no.2
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• pp.107-138
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• 2013

The purpose of this article is to awaken our colleagues to the culture and mind issues that have been forgotten or neglected by contemporary psychiatry under the prevalence of materialistic orientation. Cultural psychiatry too, though it has been contributed a great deal to widen the mental vision of psychiatry, has revealed several limitations in its approach. In the course of one sided search for culture specific factors in relation to mental health, conventional cultural psychiatry has neglected an effort to explore the common root underlying the different cultures and the common foundation of human mind. Cross sectional comparisons of the cultures alone have inevitably prevented the global considerations to culutre and mind in historical aspects and the dynamic interactions between mind and culture more in depth. The author suggested that the total view of mind and total approach of analytical psychology of C.G. Jung might be capable to replenish those limitations. Author explained the ways of C.G. Jung's observations and experiences of non-western culture and his concepts of culture and mind. The author demonstrated Jung's view of culture with the example of Filial Piety, Hyo, the Confucian moral norm which can be regarded as components of the collective consciousness though connected with archetypal patterns of behavior of intimacy between parent and child. In regard to the coexistence of multi-religious cultures in Korea the author made a proposal of 'culture spectrum' model for understanding value orientations of person in religious cultures. He identified in case of the Korean 4 types of cultural spectrums: Person with predominantly the Buddhist culture; with the Confucian; with the Shamanist; and with the Christian culture. The author also made an attempt to depict the dynamic interactions of different religious cultures in historical perspectives of Korea. Concepts of mind from the Eastern thoughts were reviewed in comparison with Jung's view of mind. The Dao of Lao Zi, One Mind by Wonhyo, the Korean Zen master from the 7th century, the Diagram of the Heaven's Decree by Toegye, a renowned Neo-Confucianist of Korea from the 16th century and his theory of Li-Ki, were explored and came to conclusion that they represent certainly the symbol of the Self in term of C.G. Jung. The goal of healing is 'the becoming whole person'. Becoming whole person means bringing the person as an individual to live not only within the specific culture but also to live in the world beyond the culture which is deeply rooted in the primordial foundation of human mind.

• Journal of Intelligence and Information Systems
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• v.23 no.2
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• pp.19-38
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• 2017

Collaborative filtering (CF) algorithm has been popularly used for implementing recommender systems. Until now, there have been many prior studies to improve the accuracy of CF. Among them, some recent studies adopt 'hybrid recommendation approach', which enhances the performance of conventional CF by using additional information. In this research, we propose a new hybrid recommender system which fuses CF and the results from the social network analysis on trust and distrust relationship networks among users to enhance prediction accuracy. The proposed algorithm of our study is based on memory-based CF. But, when calculating the similarity between users in CF, our proposed algorithm considers not only the correlation of the users' numeric rating patterns, but also the users' in-degree centrality values derived from trust and distrust relationship networks. In specific, it is designed to amplify the similarity between a target user and his or her neighbor when the neighbor has higher in-degree centrality in the trust relationship network. Also, it attenuates the similarity between a target user and his or her neighbor when the neighbor has higher in-degree centrality in the distrust relationship network. Our proposed algorithm considers four (4) types of user relationships - direct trust, indirect trust, direct distrust, and indirect distrust - in total. And, it uses four adjusting coefficients, which adjusts the level of amplification / attenuation for in-degree centrality values derived from direct / indirect trust and distrust relationship networks. To determine optimal adjusting coefficients, genetic algorithms (GA) has been adopted. Under this background, we named our proposed algorithm as SNACF-GA (Social Network Analysis - based CF using GA). To validate the performance of the SNACF-GA, we used a real-world data set which is called 'Extended Epinions dataset' provided by 'trustlet.org'. It is the data set contains user responses (rating scores and reviews) after purchasing specific items (e.g. car, movie, music, book) as well as trust / distrust relationship information indicating whom to trust or distrust between users. The experimental system was basically developed using Microsoft Visual Basic for Applications (VBA), but we also used UCINET 6 for calculating the in-degree centrality of trust / distrust relationship networks. In addition, we used Palisade Software's Evolver, which is a commercial software implements genetic algorithm. To examine the effectiveness of our proposed system more precisely, we adopted two comparison models. The first comparison model is conventional CF. It only uses users' explicit numeric ratings when calculating the similarities between users. That is, it does not consider trust / distrust relationship between users at all. The second comparison model is SNACF (Social Network Analysis - based CF). SNACF differs from the proposed algorithm SNACF-GA in that it considers only direct trust / distrust relationships. It also does not use GA optimization. The performances of the proposed algorithm and comparison models were evaluated by using average MAE (mean absolute error). Experimental result showed that the optimal adjusting coefficients for direct trust, indirect trust, direct distrust, indirect distrust were 0, 1.4287, 1.5, 0.4615 each. This implies that distrust relationships between users are more important than trust ones in recommender systems. From the perspective of recommendation accuracy, SNACF-GA (Avg. MAE = 0.111943), the proposed algorithm which reflects both direct and indirect trust / distrust relationships information, was found to greatly outperform a conventional CF (Avg. MAE = 0.112638). Also, the algorithm showed better recommendation accuracy than the SNACF (Avg. MAE = 0.112209). To confirm whether these differences are statistically significant or not, we applied paired samples t-test. The results from the paired samples t-test presented that the difference between SNACF-GA and conventional CF was statistical significant at the 1% significance level, and the difference between SNACF-GA and SNACF was statistical significant at the 5%. Our study found that the trust/distrust relationship can be important information for improving performance of recommendation algorithms. Especially, distrust relationship information was found to have a greater impact on the performance improvement of CF. This implies that we need to have more attention on distrust (negative) relationships rather than trust (positive) ones when tracking and managing social relationships between users.

• Journal of Oral Medicine and Pain
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• v.30 no.3
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• pp.301-317
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• 2005

The number of patients with tongue carcinoma is increasing rapidly among young individuals in many parts of the world. Oral carcinoma progresses from hyperplastic lesion through dysplasia to invasive carcinoma and the concept of "field cancerization" with molecular alteration has been suggested for oral cavity carcinogenesis. Significant improvement in treatment and prognosis will depend on more detailed understanding of the multi-step process leading to cancer development. To induce tongue carcinoma in rat by 4-NQO, each drinking water was made to 10 ppm, 25 ppm, 50 ppm and control (only D.W. without 4-NQO). Specimens were classified into 4 groups such as control, I (mild & moderate dysplasia), II (severe dysplasia and carcinoma in situ), III (carcinoma). The mRNA expressions of Bcl-2 family were evaluated by RT-PCR technique. For anti-apoptotic Bcl-2 family, mRNA expression of Bcl-w was down-regulated in all stages of tongue carcinogenesis model. However, mRNA expression of Bcl-2 was up-regulated. For pro-apoptotic Bcl-2 family, all members were down-regulated in all stages of tongue carcinogenesis model except for Bad mRNA in group III. In terms of BH3 only protein, mRNA expressions of Bok and Mcl-1 were down regulated in all stages of specimen, but Bmf in group II and BBC3 in group III were up-regulated. Our current findings demonstrated the involvements of mRNA expression of Bcl-2 family in multi-step tongue carcinogensis. This highlights the necessity for continued efforts to discover suitable biomakers (Bcl-2 family) for early diagnosis of the disease, and to understand its pathogenesis as a first step in improving methods of treatment. The discovery of these potential biomarkers and molecular targets for cancer diagnostics and therapeutics has the potential to significantly change the clinical approach and outcome of the disease.