• Journal of the HCI Society of Korea
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• v.5 no.1
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• pp.37-43
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• 2010

Twitter has been continuously growing since October, 2006. Especially, not only the users and the number of messages have been increasing but also a new concept in social networking called 'micro blogging' has diffused. Within Korea, service such as 'me2day' has already been introduced and the improvement of internet accessibility within mobile devices is expected to expand the 'micro blogs'. In this point, this research is executed to study the new medium, 'micro blog'. To do so, we collected and analyzed Twitter logs of Korean users. Especially, we were curious about the extreme heavy users using Twitter, despite of the linguistic and cultural barrier of the foreign service. Who they are, why and how they use the 'micro blog'. First, we reviewed the general aspect of followers and messages by collecting a certain number of random samples. Using the Lorenz curve we found out that there was the imbalance within the users and based on this phenomenon we deducted an extreme heavy user group. In order to perform further analysis, log analysis was performed on the extreme heavy users. As the result, the users used multiple mobile and desktop 'Twitter' clients. The usage pattern was similar to that of internet usage time but was used during their "micro" time. The users using 'Twitter' not only to spread messages about important information, special events and emotions, but also as a habitual 'chatting tool' to express ordinary personal chats similar to SMS and IM services. In this research, it is proved that 68% of the total messages were ordinary personal chats. Also, with 24% of the total messages were retweets, we were able to find out that virtually connected 'people' and 'relationships' acted as the dominant trigger of their articulation.

• Journal of the HCI Society of Korea
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• v.13 no.3
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• pp.43-53
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• 2018

Facebook, which has the largest number of users worldwide, has both positive and negative effects on our lives and society. The positive effects include social support from others, relationship building, entertainment, etc. In contrast, Facebook users also experience negative emotions such as tiredness and irritation, resulting in dissatisfaction as well as withdrawal from Facebook. The current study investigates both positive and negative effects of the use of by different demographic characteristics (i.e., age and gender), Facebook usage pattern (i.e., posters vs. lurkers), and Facebook usage time and frequency. The results show that (1) female users (vs. male users) feel higher level of fatigue and display stronger intention to discontinue Facebook. Moreover, (2) posters (vs. lurkers) feel higher level of positive emotions and social support, and stronger intention to continue Facebook. Lastly, (3) heavy users (vs. light users) exhibit higher level of positive emotions and stronger intentions to continue Facebook. This research sheds light on the fact that the characteristics of users affect individuals' intention to discontinue SNS and offers practical implications on the ever-expanding SNS market.

• International Area Studies Review
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• v.14 no.3
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• pp.454-476
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• 2010

In this paper is two-step trade model introduced. It is assumed that countries have 3 basic factors- capital(K), land (Z)and population(N)-as national factor endowments. As the first step, education 'produces' 'educated labor(EL)' which embodies new knowledge or new technology by using the population and capital as inputs. As the second step, manufacturing goods is produced with EL and uneducated labor(UL), and agriculture goods with land and UL. According to this model, the higher the increase rate of capital in a country is, the lower the usage rate of land is, the lower the increase rate of discount is, the country tends to export the manufacturing goods and import the agriculture goods. Trade widens the discrepancy of increase rate of EL in both countries but reduces the gap of increase rate of relative wage of EL as far as the gap of usage rate is not so big. Trade also affect real income rather than nominal income. This model can be extended to explain the migration from rural areas to urban areas when the manufacturing sector and education organization exist in urban area while the agricultural sector exist in rural area.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.3
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• pp.133-140
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• 2023

The performance of lithium ion batteries depends on the usage environment and the combination ratio of cathode materials. In order to develop a high-performance lithium-ion battery, it is necessary to manufacture the battery and measure its performance while varying the cathode material ratio. However, it takes a lot of time and money to directly develop batteries and measure their performance for all combinations of variables. Therefore, research to predict the performance of a battery using an artificial intelligence model has been actively conducted. However, since measurement experiments were conducted with the same battery in the existing published battery data, the cathode material combination ratio was fixed and was not included as a data attribute. In this paper, we define a training data model required to develop an artificial intelligence model that can predict battery performance according to the combination ratio of cathode materials. We analyzed the factors that can affect the performance of lithium-ion batteries and defined the mass of each cathode material and battery usage environment (cycle, current, temperature, time) as input data and the battery power and capacity as target data. In the battery data in different experimental environments, each battery data maintained a unique pattern, and the battery classification model showed that each battery was classified with an error of about 2%.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.723-734
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• 2008

In this paper, the problems and betterment plan in operating district units plan are studied by selecting typal case locations based on the types of district units plan of the city of Busan. According to the types, 4 locations of 'type of maintaining preexisting district' and 3 of 'type of managing preexisting district' are selected as case locations, based on a scale and characteristics of each location.In systematical aspects of the case locations, indiscreet upward adjustment of the locations, insignificant participation of the citizens and patternization were recognized as problems. And setting accurate standards for target and range of alteration in line with usage plan of the locations would be necessarily urgent. So through the analysing process of the problems arisen from the case locations I would suggests necessary solutions to improve the effectiveness of the district units plan. And In planning aspects, the similarity between the basic directions and the object, batch-application of the density plan, inadequacy of the usage plan, allocations and patterns of structures, and color planning were recognized to have problematic points. Consequently distinguished specific operating-guidelines would be necessary to achieve the basic directions and the object of district units plan. Furthermore, the building-to-land ratio and floor space index are needed to be exactly calculated through providing accurate and logical standards for appropriate development density of structures.

• Journal of Sasang Constitutional Medicine
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• v.23 no.3
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• pp.275-284
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• 2011

1. Objective: This literary review investigates Lee Jema's clinical experiences with Soyang-type patients and their influence on his conceptualization of the Soyang physiology and pathology. 2. Methods: 1) The case reports in "Soyang constitutional type: Spleen Cold-based Exterior-Cold disease" were compared before and after the Sinchuk revision to explore the temporal change in the Sasang medical concepts. 2) The texts in Donguisusebowon (Gabo edition) and Donguisusebowon (Sasangchobongwon) were analyzed to investigate the pathological concepts appearing before the completion of the Donguisusebowon (Gabo edition). 3) The texts in Donguisusebowon (Sinchuk edition) was analyzed to investigate the pathological concepts formed between the Gabo and Sinchuk editions of Donguisusebowon. 3. Results and Conclusions: 1) Gabo edition : The Gabo edition divided the External-origin Exterior disease into Cold-dominant (Heat-moderate) and Heat-dominant (Cold-moderate) patterns and differentiated the severity of Exterior-based Exterior disease and Interior-based Interior disease into mild, moderate, severe, and critical conditions. Cold-damage Delirium disease pattern was categorized as an Interior-based Interior disease, and the treatment protocol using Baekho-tang (Baihu-tang) was established. The stool condition and bowel movement reflecting the patient's defecation habits, the prime indicator of health in the Soyang constitutional type, were emphasized on their importance. 2) Sinchuk edition: The Delirium disease pattern was moved into the Exterior-cold disease, and the treatment protocol applying Jihwangbaekho-tang (Dihuangbaihu-tang) and Hyeongbangsabaek-san (Jingfangxiebai-san), with variational usage of Gypsum, was newly established. The Seong-Jeong and basal disease patterns were suggested as important factors in treating the patients. Also, it was proposed that the symptoms and signs reflecting the condition of the life-preserving energy be assessed to understand the patient's current condition. The importance of post-acute rehabilitation and aftercare as well as the most appropriate acute-stage treatment were emphasized.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.1-15
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• 1998

Purpose : The study for changes in components and acitvities of Artemisiae Herba at various processing temperature is generally regarded as a foundation in setting the optimum heat-processing temperature and for getting the maximum activities for medical usage of this herb. Methods: Therefore some experiments were performed either in vitro or in vivo and various changes were observed - the changes in the weitht of Artemisiae Herba, the changes in the relative amount of three kinds of extracts from Artemisiae Herba ( diluted ethanol extract, water extract, ether extract ), the TLC pattern of essential oil at various processing temperature, the existance of inhibitory effects both on ${\beta}$-Glucuronidase activities, and on heat-induced hemolysis, the effects on increased vascular permeability. The valid results derived from the experiments are as follows. Results: 1. The weight of Artemisiae Herba prominently decreased at 240^{\circ}C$. 2. The contents of diluted ether extract were maximum in the unprocessing condition. Those of water extract were maximum at 180^{\circ}C$ and at 210^{\circ}C$. and the changes of diluted ethanol extract at 150^{\circ}C$. 3. The TLC pattern of essential oil in Artemisiae Herba at various processing temperature showed that a component began to increase at Rf 0.56 and another component began to decrease at Rf 0.86. 4. The contents of Eupatilin in Artemisiae Herba at various processing temperature continued to decreased in proportion to the temperature rise, the extent of which was prominent at 210^{\circ}C$, and was unnoticeable at 270^{\circ}C$. 5. Inhibitory effects on ${\beta}$-Glucuronidase activities, trypsin activities and heat-induced hemolysis increased in proportion to the density of Artemisiae Herba. Inhibitory effects on ${\beta}$-Glucuronidase activities and trypsin activities were relatively high at 180^{\circ}C$ while on the writhing syndrome and inhibitory effects on increased vascular permeability induced by acetic acid were maximum at 240^{\circ}C$. those on heat-induced hemolysis were relatively high at 240^{\circ}C$. 6. In vivo, both analgesic effects Conclusions: To maximize of the effectiveness of Artemmisiae Herba, the ideal heating temperature is in the range of 180^{\circ}C{\sim}240^{\circ}C$.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.413-413
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• 2014

In this paper, we present a fabrication method of functionalized gold nanostructures on flexible substrate that can be implemented for plasmonic sensing application. For biomolecular sensing, many researchers exploit unconventional lithography method like nanoimprint lithography (NIP), contact transfer lithography, soft lithography, colloidal transfer printing due to its usability and easy to functionalization. In particular, nanoimprint and contact transfer lithography need to have anti-adhesion layer for distinctive metallic properties on the flexible substrates. However, when metallic thin film was deposited on the anti-adhesion layer coated substrates, we discover much aggravation of the mold by repetitive use. Thus it would be impossible to get a high quality of metal nanostructure on the transferred substrate for developing flexible electronics based transfer printing. Here we demonstrate a method for nano-pillar mold and transfer the controllable nanoparticle array on the flexible substrates without an anti-adhesion layer. Also functionalization of gold was investigated by the different length of thiol applied for effectively localized surface plasmonic resonance sensing. First, a focused ion beam (FIB) and ICP-RIE are used to fabricate the nanoscale pillar array. Then gold metal layer is deposited onto the patterned nanostructure. The metallic 130 nm and 250 nm nanodisk pattern are transferred onto flexible polymer substrate by bi-layer functionalized contact imprinting which can be tunable surface energy interfaces. Different thiol reagents such as Thioglycolic acid (98%), 3-Mercaptopropionic acid (99%), 11-Mercaptoundecanoic acid (95%) and 16-Mercaptohexadecanoic acid (90%) are used. Overcoming the repeatedly usage of the anti-adhesion layer mold which has less uniformity and not washable interface, contact printing method using bi-layer gold array are not only expedient access to fabrication but also have distinctive properties including anti-adhesion layer free, functionalized bottom of the gold nano disk, repeatedly replicate the pattern on the flexible substrate. As a result we demonstrate the feasibility of flexible plasmonic sensing interface and anticipate that the method can be extended to variable application including the portable bio sensor via mass production of stable nanostructure array and other nanophotonic application.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.4
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• pp.647-661
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• 1997

The resin modified glass ionomer cements(RMGICs) have been used for years since 1989. Recently it has been developed for luting of fixed restorations. To evaluate the bond strength and marginal leakage of RMGICs for luting usage, the 80 extracted human molars which had uniform area of exposed dentin were cemented with 3 types of RMGICs(Fuji Duet, Advance, Vitremer), a conventional Glass Ionomer Cement(GIC-Fuji I), and a resin cement (Panavia 21) to base metal alloy(Ni-Cr-Be). After thermocycling the specimens were immersed in basic fuschin dye for measuring marginal leakage. The shear bond strength was measured with Instron and the maximum dye penetration was measured to 0.1mm. The types of fractured patterns were determined with stereoscope(${\times}7.5$). The results are as follows. 1. The difference between 3 RMGICs and a conventional GIC in shear bond strength was not statistically significant. It seemed that RMGICs had lower shear bond strength than resin cement. (p<0.01) 2. The mean scores of marginal leakage had no significant difference between the resin cement and 3 RMGICs but it was much higher in conventional GIC than the RMGICs (p<0.05) 3. It was determined that the manufacturer and the methods of dentin pretreatment determined the pattern of fracture surfaces and the frequency of adhesive failure between teeth and 3 RMGICs standed as in following order - Vitremer, Advance, Fuji Duet. (p<0. 01) When the fracture pattern was analyzed, it could be said that the materials and the method of dentin pretreatment have much effect on bonding states. This means that the dentin bonding agents should be improved. But the limited products in this experiment can not evaluate the physical properties of the entire RMGICs. Therefore a further study which can evaluate various RMGICs should be in progress to develope better cements.

• The Korean Journal of Pesticide Science
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• v.10 no.3
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• pp.183-188
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• 2006

A nation-wide monitoring survey was performed to look into pesticide use pattern and amount on farmers' field after the national registration of pesticides from 2003 to 2004. Tow hundred ninety two leading farmers involved in the survey were chosen from main cultivating regions of targeted crops in consideration with area. Most farmers involved in the survey follow the safe use guideline of pesticides, while their information to select and making-decision for purchasing pesticides were done according to the recommendation of mainly pesticide market dealers or agricultural cooperative dealers. Used amount of pesticide per unit cropping area was surveyed as 5.51 on paddy, 3.91 on field cabbage, 2.93 on greenhouse cabbage, 0.76 on lettuce, 0.55 on spinach, 1.34 on perilla leaf, 4.89 on leek and 0.42 kg $ha^{-1}$ on young radish. As compound with those surveyed from 1999 to 2000, the pesticide amounts used for rice, lettuce and perilla leaf were reduced while that for cabbage was increased.