• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.5A
• /
• pp.407-415
• /
• 2010

In Korea, more than 90% of the total number of steel bridges built for 40~70 m span length is a steel box-girder bridge type. A steel box-girder bridge is suitable for long span or curved bridges with outstanding flexural and torsional rigidity as well as good constructability and safety. However, a steel box-girder bridge is uneconomical, requiring many secondary members and workmanship such as stiffeners and ribs requiring welding attachments to flanges or webs. Therefore, in US and Japan, a plate girder bridge, which is relatively cheap and easy to construct is generally used. One type of the plate girder bridge is the two- or three-main girder plate bridge, which is a composite plate girder bridge that minimizes the number of required main girders by increasing the distance between the adjacent girders. Also, for the simplification of girder section, the stiffener which requires attachment to the web is not required. The two-main steel girder plate bridge is a representative type of plate girder bridges, which is suitable for bridges with 10 m effective width and has been developed in the early 1960s in France. To ensure greater safety of two- or three-main girder plate bridges, a larger steel section is used in the bridge domestically than in Europe or Japan. Also, the total number of two- or three-main girder plate bridge constructed in Korea is significantly less than the steel box girder bridge due to a lack of designers' familiarity with more complex design detailing of the bridge compare to that of a steel box girder bridge design. In this study, a new construction method called Turn Over method is proposed to minimize the steel section size used in a two- or three-main girder plate bridge by applying prestressing force to the member using confining concrete section's weight to reduce construction cost. Also, a full scale 20 m Turn Over girder specimen and a Turn Over girder bridge specimen were tested to evaluate constructability and structural safety of the members constructed using Turn Over process.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.22 no.1
• /
• pp.5-10
• /
• 2012

In general, the fabrications of the LEDs with mesa structure are performed grown by MOCVD method. In order to etch and separate each chips, the LEDs are passed the RIE and scribing processes. The RIE process using plasma dry etching occur some problems such as defects, dislocations and the formation of dangling bond in surface result in decline of device characteristic. The SAG method has attracted considerable interest for the growth of high quality GaN epi layer on the sapphire substrate. In this paper, the SAG method was introduced for simplification and fabrication of the high quality epi layer. And we report that the size of selective area do not affect the characteristics of original LED. The diameter of SAG circle patterns were choose as 2500, 1000, 350, and 200 ${\mu}m$. The SAG-LEDs were measured to obtain the device characteristics using by SEM, EL and I-V. The main emission peaks of 2500, 1000, 350, and 200 ${\mu}m$ were 485, 480, 450, and 445 nm respectively. The chips of 350, 200 ${\mu}m$ diameter were observed non-uniform surface and resistance was higher than original LED, however, the chips of 2500, 1000 ${\mu}m$ diameter had uniform surface and current-voltage characteristics were better than small sizes. Therefore, we suggest that the suitable diameter which do not affect the characteristic of original LED is more than 1000 ${\mu}m$.

• Journal of the Korean Society of Costume
• /
• v.24
• /
• pp.15-28
• /
• 1995

This thesis focuses on the study of costume and ornaments of Shilla which had been severely affected by Uighur, and those of Uighur in Uighur self-governing district located in Shin Kang. East Turkestan, in Centrals Asia. This study aims to identifty the way of intergration of Uighur's costume and ornaments into Shilla, and orgins of Shill's costume and ornaments which had amix of internationl elelemnts thoursh cross exchanges, by comparing the differences between the two, and at the same time to clarify the pedigree of Korean costume and ornaments which are said to be udner a severe Chinese influence, by highlingting its uniqueness and originality . The result of the study demonstrates and originality of SHilla by melting foreign cultures into its own style in the process of accepting them. This means that the Shilla has recreated them in t도 form of simplification, and added naturalistic abstratness which is an element of Norther culture. The costume and ornaments are divided into coronets men's costuem, women's costume, and accessories 1. Coroncts A horse-riding man, and the costume type of 유고제 착유지체형 tell the Northern culture's influence on 백화수피기마인물채화담립 and patterns of a lotus flowr and arabesque show the 백화수피기마인물채색답립 has an influence of Buddhism with cluture of bordering countries of Western China , The origin of 뱍회수피제안형건(원정형, 방정형) lies in Northern cultures which can be found in ancient tombs of the Huns in noin-Ila , and stone caves of Jizil in Kochang. The wall paintings in Alexandropol, Murutuk and 돈황 No. 409 cave show that 초화형입식계금관 is under the influence of Northern culture, and Bezerkrick No, 25 cave and 회 번 in Kocho also show 수목녹각형입식관 is under the influence of Northern culture, with its origin in Novecherkaask. In this regard, the transformed coroncts of Shilla has shows a blended culture of Shilla with Nothern, Chinese, and Western cultures. 2. Men's Costume 반령포 derives from cultures of bordering countries of Western China centering around Uighur and Turkey. 연주문 in Uighur prince's costume and in Uighur paintings of Central Asia were reflected into the arts of Shilla in a direct way, and the motive of Uighur was deviatelly expressed at Shilla's arts in the form of simplicity , and naturalistic abstract paintings as in shown at 입수쌍조문 in tiles and brick. Along with this , 고착지체형 costume originates from Eurasia's Northern horseriding costumes as was shown in a golden man in B.C.4-5C which is now possessed by Kazakstan Republic Academy Archelogy Center Museum, and a golden figure from Skitai ancient caves, an the origin is carried away into wall paintings of Kizil No.14. cave in 8c and Astana's early period ancient tomb. No.6. 3. Women's Costume The hair styles of Shilla people are either 변발 or up -style with a lot of hair around it whose origin can be seen in Astana No.216 and No.187 caves of Kochang and Uighur's wall paintings of royal princess's hair style. Astana's middle period No. 206 and No.230 tombs reveal the its origin of 고착장군 while Astana early period No. 6 tomb shows that of 광유풍만형. 4. Accessories The earrings with small golden beads is seen at earring of figure holding a sword in wall painting of figure holding a sword in wall painting of Kizil in about 5 C. and those of a offering people in Sorchuk wall paintings. The earrings with small golden beads originates from a golden pendant of Shivargan, Afganistan, and golden pendants and other golden and metal accessories from Chrioba ancient tombs in Skiti Critia peninsula. Shilla's costume derives from the costume style of horse-ridding man, which proves the fact that Shilla people are horse-ridding peoplewith excellent horse-ridding techniques, and traditions. The people of Shilla are from horse-ridding people of local mounted momads in Northern part of Siberia steppe and this origin of Northern culture had been carried into Uighur in East Turkestan. At the same time , Shilla has a wealth and power since it was rich in gold and iron , thus producing lots of materials made of them. The results of this study emphasizes Shilla's identity and self-control by creating an independent an innovative heterogeneous culture since Shill's active exchanges with East Asia allowed it to accept the most civilized Uighur culture in East Turkestan among Altai languate which had frequent cross contacts with India and Europe.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.36 no.6
• /
• pp.1-11
• /
• 2009

This study focuses on Abstract Types in Contemporary Landscape Design. The formation and artistry of contemporary landscape design reveals many areas which Previously have not been able to be expressed in scenic landscape thanks to the deviation of the genre in contemporary landscape and the hybridization that has occurred among architecture, landscape and art genres. The focus of this study is basic research concerning "the abstract", which is used as a creative artistic theory in a variety of art fields such as landscape, architecture and painting. Through a theoretical establishment of "the abstract", its process of change, and the discovery of its contemporary principles, the relationship between each art field in landscapes and the formation of the abstract, abstract language, and abstract properties have been studied. The use of the abstract in contemporary landscape design can be classified in three ways: Inductive abstract representing conceptual transcendental symbols not logically but rather through intuition and transcendental cognition to display the inner expressions, ideas and minds of the artists. Second, a deductive abstract represents an expansive, logical model for the simplification of objects, distortion, exaggeration based on knowledge and logical reasoning about objective fact based on traditional realism. The complexity of the abstract is a concept that is bound to both the deductive & inductive abstract. As a major trend, the concept of "The abstract" in contemporary landscape has been putting forth ever-deeper roots. New trends like abstract works and landscape architecture reflecting the artist's inner expression, in particular, will provide fertile soil for landscape in the future. Further research about the concept of "the abstract" will also be necessary in the time to come.

• Journal of Hospice and Palliative Care
• /
• v.16 no.1
• /
• pp.10-19
• /
• 2013

Purpose: Home-based care providers were surveyed to assess the effect of collaborative service between Gyeongnam Regional Cancer Center (GRCC) and public health centers (PHCs) in Gyeongnam province. Methods: Twenty home-based care providers who had previously participated in the GRCC-PHC care project were recruited from nine PHCs and were surveyed using a questionnaire developed by specialists. Questions were rated using the 5-point Likert scale ranging from "strongly disagree (-2)" to "strongly agree (+2)" and each score was multiplied by the corresponding number of respondents (n=20) with the maximum score of 40. Results: Between January 2008 and December 2011, 73 patients were registered to the collaborative service: 72 by GRCC and one by PHC. Home-based care providers marked the highest score (23 points) to "The collaborative service contributed to patients and their family's psychological stability" and the lowest score (11 points) to "The collaborative service was generally helpful for home-based cancer management." For possible suggestions to improve the service, the highest score (35 points) was given to "Simplification of the hospitalization process" followed by "Substantial benefits for patients at their visit to the hospital" (34 points). Conclusion: The results revealed several limitations of the GRCC-PHC collaborative care service for terminal cancer patients. The service could be further improved by developing measures to address the limitations and a service model tailored to region-specific needs.

• Korean Journal of Heritage: History & Science
• /
• v.54 no.4
• /
• pp.60-77
• /
• 2021

From 2007 to 2011, four Goryeo Dynasty vessels, namely the Taean treasure ship, Taean Mado Shipwreck No.1, No.2, No.3 were discovered in Taean area, Chungcheongnam-do province. From the shipwrecks, 175 pieces of mokkan (wooden tablet) were excavated. These mokkans are the only case of Goryeo Dynasty and represent the unique usage of mokkan as cargo tags, after the paper replaced the wooden tablets as writing materials. The Taean mokkans provide details, such as the year, recipient, port of origin, types of the cargo, quantity and unit, the name of the responsible person for shipment. Thus, they enable us to speculate about the characteristics of the cargo. Furthermore, through studying the writing style, form, material and manufacturing method, researchers can extract which form and characteristics were favored at that time. The Taean mokkans have no preset style for writing. Therefore, they can be written selectively and freely. And since the mokkan were attached to cargos, mokkans with furrows on upper side were favored, and efficiency and simplification of the manufacturing process were priorities in making mokkans. The Taean mokkans can be compared to those from the Shinan ship and the Quanzhou ship because those are of the same era and use. On the writing styles and information, Chinese mokkans are focused on the cargo owners, while The Taean mokkan includes more detailed information, such as the recipients. In forms, Chinese mokkans have maximum thickness of 1.0 centimeter and have pointed edges in lower parts, while mokkans from Taean do not have fixed thickness or edges. Furthermore, Chinese mokkans and Korean mokkans have different styles from manufacturing methods and material selections. These differences between Chinese and Goryeo mokkan are related to the differences between littoral-transport Goryeo ships and ocean-transport Chinese ships, such as shipping distances, types of cargo, shipping systems, packing methods, and transport operators. At the moment, because there are only small amount of data and materials of Chinese mokkan, comparative studies regarding Goryeo and Chinese mokkan can only be fragmentary. However, this article can be a base from which to expand the scope of Goryeo mokkan studies.

• Journal of Intelligence and Information Systems
• /
• v.27 no.3
• /
• pp.157-173
• /
• 2021

With the development of information technology, the amount of available information increases daily. However, having access to so much information makes it difficult for users to easily find the information they seek. Users want a visualized system that reduces information retrieval and learning time, saving them from personally reading and judging all available information. As a result, recommendation systems are an increasingly important technologies that are essential to the business. Collaborative filtering is used in various fields with excellent performance because recommendations are made based on similar user interests and preferences. However, limitations do exist. Sparsity occurs when user-item preference information is insufficient, and is the main limitation of collaborative filtering. The evaluation value of the user item matrix may be distorted by the data depending on the popularity of the product, or there may be new users who have not yet evaluated the value. The lack of historical data to identify consumer preferences is referred to as data sparsity, and various methods have been studied to address these problems. However, most attempts to solve the sparsity problem are not optimal because they can only be applied when additional data such as users' personal information, social networks, or characteristics of items are included. Another problem is that real-world score data are mostly biased to high scores, resulting in severe imbalances. One cause of this imbalance distribution is the purchasing bias, in which only users with high product ratings purchase products, so those with low ratings are less likely to purchase products and thus do not leave negative product reviews. Due to these characteristics, unlike most users' actual preferences, reviews by users who purchase products are more likely to be positive. Therefore, the actual rating data is over-learned in many classes with high incidence due to its biased characteristics, distorting the market. Applying collaborative filtering to these imbalanced data leads to poor recommendation performance due to excessive learning of biased classes. Traditional oversampling techniques to address this problem are likely to cause overfitting because they repeat the same data, which acts as noise in learning, reducing recommendation performance. In addition, pre-processing methods for most existing data imbalance problems are designed and used for binary classes. Binary class imbalance techniques are difficult to apply to multi-class problems because they cannot model multi-class problems, such as objects at cross-class boundaries or objects overlapping multiple classes. To solve this problem, research has been conducted to convert and apply multi-class problems to binary class problems. However, simplification of multi-class problems can cause potential classification errors when combined with the results of classifiers learned from other sub-problems, resulting in loss of important information about relationships beyond the selected items. Therefore, it is necessary to develop more effective methods to address multi-class imbalance problems. We propose a collaborative filtering model using CGAN to generate realistic virtual data to populate the empty user-item matrix. Conditional vector y identify distributions for minority classes and generate data reflecting their characteristics. Collaborative filtering then maximizes the performance of the recommendation system via hyperparameter tuning. This process should improve the accuracy of the model by addressing the sparsity problem of collaborative filtering implementations while mitigating data imbalances arising from real data. Our model has superior recommendation performance over existing oversampling techniques and existing real-world data with data sparsity. SMOTE, Borderline SMOTE, SVM-SMOTE, ADASYN, and GAN were used as comparative models and we demonstrate the highest prediction accuracy on the RMSE and MAE evaluation scales. Through this study, oversampling based on deep learning will be able to further refine the performance of recommendation systems using actual data and be used to build business recommendation systems.

• Economic and Environmental Geology
• /
• v.56 no.4
• /
• pp.435-445
• /
• 2023

A delta is a depositional landform that is formed when sediment transported by a river is deposited in a relatively low-energy environment, such as a lake, sea, or a main channel. Among these, a delta formed at the confluence of rivers has a great importance in river management and research because it has a significant impact on the hydraulic and sedimentological characteristics of the river. Recently, the equilibrium state of the confluence area has been disrupted by large-scale dredging and construction of levees in the Nakdong River. However, due to the natural recovery of the river, the confluence area is returning to its pre-dredging natural state through ongoing sedimentation. The time-series data show that the confluence delta has been steadily growing since the dredging, but once it reaches a certain size, it repeats growth and retreat, and the overall size does not change significantly. In this study, we developed a model to explain the sedimentation-erosion processes in the confluence area based on the assumption that the confluence delta reaches a dynamic equilibrium. The model is based on two fundamental principles: sedimentation due to supply from the tributary and erosion due to the main channel. The erosion coefficient that represents the Nakdong River confluence areas, was obtained using data from the tributaries of the Nakdong River. Sensitivity analyses were conducted using the developed model to understand how the confluence delta responds to changes in the sediment and water discharges of the tributary and the main channel, respectively. We then used annual average discharge of the Nakdong River's tributaries to predict the dynamic equilibrium positions of the confluence deltas. Finally, we conducted a simulation experiment on the development of the Gamcheon-Nakdong River delta using recorded daily discharge. The results showed that even though it is a simple model, it accurately predicted the dynamic equilibrium positions of the confluence deltas in the Nakdong River, including the areas where the delta had not formed, and those where the delta had already formed and predicted the trend of the response of the Gamcheon-Nakdong River delta. However, the actual retreat in the Gamcheon-Nakdong River delta was not captured fully due to errors and limitations in the simplification process. The insights through this study provide basic information on the sediment supply of the Nakdong River through the confluence areas, which can be implemented as a basic model for river maintenance and management.