• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.1
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• pp.90-102
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• 2012

Sansuyucheop by Heojoobugun(虛舟府君) as the subject of this study is a 십이-width picture album by the eldest grandson of 11 generations for Goseong Lee family, Lee Jong Ak(李宗岳: 1726-1773), a figure having five habits(五癖) for ancient documents(古書癖), playing the gayageum(彈琴癖), flowering plant(花卉癖), paintings and calligraphic works(書畵癖) and boating(舟遊癖) etc., who boated with 18 relatives, and those by marriage from old home, home of mother's side, wife's home, and his home for 5 days Apr. 4 through 8, 1763, starting from Imcheonggak, through Yangjeong(羊汀), Chiltan(七灘), Sabin Auditorium(泗濱書院), Seonchang(船倉), Nakyeon(落淵), Seonchal(仙刹), Seonyujeong(仙遊亭), Mongseongak(夢仙閣), Baekwoonjeong(白雲亭) and Naeap Village(川前里), Iho(伊湖), Seoeodae(鮮魚帶) to the returning point, Bangujeong(伴鷗亭), cruised magnificent views around Banbyeoncheon called 'Andong 8 Gyeong' or 'Imhagugok', and whenever the boat anchored, appreciated the scenery at each point, and enjoyed and loved arts playing the geomungo. This study reached following findings through grasping physical, ecological, visual and aesthetic changes about the places, sceneries, plant elements and past and current scenery of the width pictures expressed at this Sansuyucheop. The refinement on the boat seeing the clear river water, white sand beach, fantastically-shaped cliffs expressed at this Sansuyucheop, exchanging poems and calligraphies, and enjoying the geomungo is a good example displaying the play culture of high-class in Joseon Dynasty. Also construction of Imha Dam and Andong Dam has caused serious visual and ecological changes, making us not enable to feel the original mood of the background spots such as Yangjeonggwabeom(羊汀過帆), Chiltanhuseon(七灘候船), Sasubeomjoo(泗水泛舟), Seonchanggyeram(船倉繫纜), Nakyeonmosaek(落淵莫色), Mangcheonguido(輞川歸棹), Ihojeongdo(伊湖停棹), but only discern then landscape or sentiment through the landscape described at the canvas. The 1st picture(Donghohaeram, 東湖解纜), and the 11th picture(Seoeobanjo, 鮮魚返照) of Heojoobugun's Sansuyucheop expressed trees thought to be fallen, brad-leaf tall trees, and the 9th picture(Unjeongpungbeom, 雲亭風帆) formed a pine forest called 'Gaeho(開湖)' by Uncheongong planting 1,000 pine trees with the village people in 1617. In addition, Seunggyeongdo expressed ever-green needle leaf trees at the natural topography, and fallen-leaf tall trees around the pavilion and building. Comparative consideration of Heojoobugun's Sansuyucheop and Shinam's Dongyusipsogi(東遊十小記) showed that the location of Samgok is assumed to be Macheon and Chiltan, so Imhagugok is assumed to start from Baekunjeong of Ilgok, Igok from Imcheon and Imcheon auditorium, Samgok from Mangcheon and Chiltan, Sagok from Sabin Auditorium of Sasoo, Ogok from Songseok, Yukgok from Sooseok of Seonchang, Chilgok from Nakyeonhyeonryu, Palgok from Seonchalsa and Seonyoojeong, and Gugok from Pyong Yuheo. This study can be significant in that it could clarify that Heojoobugun's Sansuyucheop is judged to be valuable in exquisitively expressing the coast of Banbyeon River, the biggest branch stream in the Nakdong River at the latter half of Joseon Dynasty, and as a vital diagrammatical historical data to make a comparative analysis of currently rarely-seen ancestors' life traces and landscape factors with present ones.

• Journal of radiological science and technology
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• v.35 no.2
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• pp.165-172
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• 2012

We investigated the vascular characteristics of tumors and normal tissue using perfusion CT in the rabbit brain tumor model. The VX2 carcinoma concentration of $1{\times}10^7$ cells/ml(0.1ml) was implanted in the brain of nine New Zealand white rabbits (weight: 2.4kg-3.0kg, mean: 2.6kg). The perfusion CT was scanned when the tumors were grown up to 5mm. The tumor volume and perfusion value were quantitatively analyzed by using commercial workstation (advantage windows workstation, AW, version 4.2, GE, USA). The mean volume of implanted tumors was $316{\pm}181mm^3$, and the biggest and smallest volumes of tumor were 497 $mm^3$ and 195 $mm^3$, respectively. All the implanted tumors in rabbits are single-nodular tumors, and intracranial metastasis was not observed. In the perfusion CT, cerebral blood volume (CBV) were $74.40{\pm}9.63$, $16.08{\pm}0.64$, $15.24{\pm}3.23$ ml/100g in the tumor core, ipsilateral normal brain, and contralateral normal brain, respectively ($p{\leqq}0.05$). In the cerebral blood flow (CBF), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($962.91{\pm}75.96$ vs. $357.82{\pm}12.82$ vs. $323.19{\pm}83.24$ ml/100g/min). In the mean transit time (MTT), there were significant differences between the tumor core and both normal brains ($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($4.37{\pm}0.19$ vs. $3.02{\pm}0.41$ vs. $2.86{\pm}0.22$ sec). In the permeability surface (PS), there were significant differences among the tumor core, ipsilateral and contralateral normal brains ($47.23{\pm}25.45$ vs. $14.54{\pm}1.60$ vs. $6.81{\pm}4.20$ ml/100g/min)($p{\leqq}0.05$). In the time to peak (TTP) were no significant differences among the tumor core, ipsilateral and contralateral normal brains. In the positive enhancement integral (PEI), there were significant differences among the tumor core, ipsilateral and contralateral brains ($61.56{\pm}16.07$ vs. $12.58{\pm}2.61$ vs. $8.26{\pm}5.55$ ml/100g). ($p{\leqq}0.05$). In the maximum slope of increase (MSI), there were significant differences between the tumor core and both normal brain($p{\leqq}0.05$), but no significant differences between ipsilateral and contralateral normal brains ($13.18{\pm}2.81$ vs. $6.99{\pm}1.73$ vs. $6.41{\pm}1.39$ HU/sec). Additionally, in the maximum slope of decrease (MSD), there were significant differences between the tumor core and contralateral normal brain($p{\leqq}0.05$), but no significant differences between the tumor core and ipsilateral normal brain($4.02{\pm}1.37$ vs. $4.66{\pm}0.83$ vs. $6.47{\pm}1.53$ HU/sec). In conclusion, the VX2 tumors were implanted in the rabbit brain successfully, and stereotactic inoculation method make single-nodular type of tumor that was no metastasis in intracranial, suitable for comparative study between tumors and normal tissues. Therefore, perfusion CT would be a useful diagnostic tool capable of reflecting the vascularity of the tumors.

• Journal of the Korean Vacuum Society
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• v.15 no.6
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• pp.563-575
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• 2006

Ti(C,N) films are synthesized by pulsed DC plasma enhanced chemical vapor deposition (PEMOCVD) using metal-organic compounds of tetrakis diethylamide titanium at $200-300^{\circ}C$. To compare plasma parameter, in this study, $H_2$ and $He/H_2$ gases are used as carrier gas. The effect of $N_2\;and\;NH_3$ gases as reactive gas is also evaluated in reduction of C content of the films. Radical formation and ionization behaviors in plasma are analyzed in-situ by optical emission spectroscopy (OES) at various pulsed bias voltages and gas species. He and $H_2$ mixture is very effective in enhancing ionization of radicals, especially for the $N_2$. Ammonia $(NH_3)$ gas also highly reduces the formation of CN radical, thereby decreasing C content of Ti(C, N) films in a great deal. The microhardness of film is obtained to be $1,250\;Hk_{0.01}\;to\;1,760\;Hk_{0.01}$ depending on gas species and bias voltage. Higher hardness can be obtained under the conditions of $H_2\;and\;N_2$ gases as well as bias voltage of 600 V. Hf(C, N) films were also obtained by pulsed DC PEMOCYB from tetrakis diethyl-amide hafnium and $N_2/He-H_2$ mixture. The depositions were carried out at temperature of below $300^{\circ}C$, total chamber pressure of 1 Torr and varying the deposition parameters. Influences of the nitrogen contents in the plasma decreased the growth rate and attributed to amorphous components, to the high carbon content of the film. In XRD analysis the domain lattice plain was (111) direction and the maximum microhardness was observed to be $2,460\;Hk_{0.025}$ for a Hf(C,N) film grown under -600 V and 0.1 flow rate of nitrogen. The optical emission spectra measured during PEMOCVD processes of Hf(C, N) film growth were also discussed. $N_2,\;N_2^+$, H, He, CH, CN radicals and metal species(Hf) were detected and CH, CN radicals that make an important role of total PEMOCVD process increased carbon content.

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.5
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• pp.321-327
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• 2006

In Korea, there is a growing competitive for water resources between industrial, domestic and agricultural consumer, and the environment as many other OECD countries. The demand on water use is also affecting aquatic ecosystems particularly where withdrawals are in excess of minimum environmental needs for rivers, lakes and wetland habits. OECD developed three indicators related to water use by the agriculture in above contexts : the first is a water use intensity indicator, which is expressed as the quantity or share of agricultural water use in total national water utilization; the second is a water stress indicator, which is expressed as the proportion of rivers (in length) subject to diversion or regulation for irrigation without reserving a minimum of limiting reference flow; and the third is a water use efficiency indicator designated as the technical and the economic efficiency. These indicators have different meanings in the aspect of water resource conservation and sustainable water use. So, it will be more significant that the indicators should reflect the intrinsic meanings of them. The problem is that the aspect of an overall water flow in the agro-ecosystem and recycling of water use not considered in the assessment of agricultural water use needed for calculation of these water use indicators. Namely, regional or meteorological characteristics and site-specific farming practices were not considered in the calculation of these indicators. In this paper, we tried to calculate water use indicators suggested in OECD and to modify some other indicators considering our situation because water use pattern and water cycling in Korea where paddy rice farming is dominant in the monsoon region are quite different from those of semi-arid regions. In the calculation of water use intensity, we excluded the amount of water restored through the ground from the total agricultural water use because a large amount of water supplied to the farm was discharged into the stream or the ground water. The resultant water use intensity was 22.9% in 2001. As for water stress indicator, Korea has not defined nor monitored reference levels of minimum flow rate for rivers subject to diversion of water for irrigation. So, we calculated the water stress indicator in a different way from OECD method. The water stress indicator was calculated using data on the degree of water storage in agricultural water reservoirs because 87% of water for irrigation was taken from the agricultural water reservoirs. Water use technical efficiency was calculated as the reverse of the ratio of irrigation water to a standard water requirement of the paddy rice. The efficiency in 2001 was better than in 1990 and 1998. As for the economic efficiency for water use, we think that there are a lot of things to be taken into considerations to make a useful indicator to reflect socio-economic values of agricultural products resulted from the water use. Conclusively, site-specific, regional or meteorogical characteristics as in Korea were not considered in the calculation of water use indicators by methods suggested in OECD(Volume 3, 2001). So, it is needed to develop a new indicators for the indicators to be more widely applicable in the world.

• Journal of Preventive Medicine and Public Health
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• v.22 no.4 s.28
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• pp.506-517
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• 1989

Two hundred and fifty teachers of special school (for the disabled) and 414 elementary school teachers were selected for the targets in order to compare their degrees of fatigue symptoms and to find what kind of ralationship is between subjective symptoms of fatigue and pH is the saliva. It was 30 minutes before their closing hours on April 21th, 1989 that their physical, mental and neuro-sensory symptoms and salivary pH were examined. The test results are summarized as fallows : It is observed that an interrelation between subjective fatigue and pH in their saliva shows a significant relationship between physical and neuro-sensory symptoms in a sense of statistics. The rate of subjective fatigue complained by the special teachers is higher than that by the elementary teachers. In the case of salivary pH, the special teachers' is as a whole lower than the elementary teachers'. The complain rates in each item, checked, of special teachers are generally higher than those of the elementary teachers. It is in the mental symptom related item that there are many sub-items which show significant difference. According to the average of salivary pH based on the degrees of complained symptoms shown in the pH related items, the salivary pH of the group with complained symptoms is lower than that of the group without complained symptoms. In the rate of complaints, by sex, both sexes of the special teachers show high ones, but salivary pH is low. The complain rate of mental symptoms shown by female group from the special teacher Is significantly higher(p<0.05). By age, the group in their thirties from the special teachers show the higher complain rate of mental symptoms (29.3%) and the lower salivary pH (p<0.05) than that (15.1%) of the elementary teachers belonging to the same age catagory. However, the special teachers in their forties show the lower complain rate of physical symptoms that of the elementary teachers (p<0.05). From the viewpoint of their working years, the special teachers below 14 years and elementary teachers above 15 years in their career show high complain rates. Among those who belong to the catagory of 10-14 working years, the special teachers show the higher complain rate of mental symptoms than that of their counterparts. In the case of the salivary pH, the special teachers of all working-year catagories show the higher pH than that of the elementary teachers. But there is not significantly difference. From the viewpoint of sleeping hours in the previous night of the questionaire surveyed, among those who slept for over 7 hours, the special teachers show the higher complain rate of mental symptoms with a significant difference, but the lower salivary pH than that of their counterparts. From the viewpoint of their marital status, existence of disease history, the special teachers show the higher complain rate of subjective fatigue, but the lower salivary pH than that of the elementary teachers respectively. According to the above results, the special teachers generally show the higher complain rate of subjective fatigue, the lower salivary pH, and the higher complain rate of mental symptoms. To prevent the possible accumulation of mental fatigue of the special teachers, ways and means to make use of leisure time, recreational facilities are necessarily provided. Since the degree of fatigue and salivary pH have a correlation to some extent, it is necessary that further continuous studies on the correlation between the degrees of fatigue and salivary pH should be pursued.

• Journal of Animal Environmental Science
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• v.18 no.2
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• pp.99-110
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• 2012

The purpose of the study is to collect basis data for to establish standard administrative processes of liquid fertilizer treatment. From this survey we could make out the key point of each step through a case of effective liquid manure treatment system in pig house. It is divided into six step; 1. piggery slurry management step, 2. Solid-liquid separation step, 3. liquid fertilizer treatment (aeration) step, 4. liquid fertilizer treatment (microorganism, recirculation and internal return) step, 5. liquid fertilizer treatment (completion) step, 6. land application step. From now on, standardization process of liquid manure treatment technologies need to be develop based on the six steps process.

• Journal of Korean Medical classics
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• v.20 no.3
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• pp.121-141
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• 2007

The outline and characteristics of the important doctors of the 'Zhe Zhong Pai'(折衷派) are as follows. Part 1. In the late Edo(江戶) period The 'Zhe Zhong Pai', which tried to take the theory and clinical treatment of the 'Hou Shi Pai (後世派)' and the 'Gu Fang Pai (古方派)' and get their strong points to make treatments perfect, appeared. Their point was 'The main part is the art of the ancients, The latter prescriptions are to be used'(以古法爲主, 後世方爲用) and the "Shang Han Lun(傷寒論)" was revered for its treatments but in actual use it was not kept at that. As mentioned above The 'Zhe Zhong Pai ' viewed treatments as the base, which was the view of most doctors in the Edo period, However, the reason the 'Zhe Zhong Pai' is not valued as much as the 'Gu Fang Pai' by medical history books in Japan is because the 'Zhe Zhong Pai' does not have the substantiation or uniqueness of the 'Gu Fang Pai', and also because the view of 'gather as well as store up' was the same as the 'Kao Zheng Pai', Moreover, the 'compromise'(折衷) point of view was from taking in both Chinese and western medical knowledge systems(漢蘭折衷), Generally the pioneer of the 'Zhe Zhong Pai' is seen as Mochizuki Rokumon(望月鹿門) and after that was Fukui Futei(福井楓亭), Wadato Kaku(和田東郭), Yamada Seichin(山田正珍) and Taki Motohiro(多紀元簡), Part 2. The lives of Wada Tokaku(和田東郭), Nakagame Kinkei(中神琴溪), Nei Teng Xi Zhe(內藤希哲), the important doctors of the 'Zhe Zhong Pai', are as follows First. Wada Tokaku(和田東郭, 1743-1803) was born when the 'Hou Shi Pai' was already declining and the 'Gu Fang Pai' was flourishing and learned medicine from a 'Hou Shi Pai' doctor, Hu Tian Xu Shan(戶田旭山) and a 'Gu Fang Pai' doctor, Yoshimasu Todo(吉益東洞). He was not hindered by 'the old ways(古方), and did not lean towards 'the new ways(後世方)' and formed a way of compromise that 'looked at hardness and softness as the same'(剛柔相摩) by setting 'the cure of the disease' as the base, and said that to cure diseases 'the old way' must be used, but 'the new way' was necessary to supplement its shortcomings. His works include "Dao Shui Suo Yan", "Jiao Chiang Fang Yi Je" and "Yi Xue Sho(醫學說)" Second. Nakagame Kinkei(中神琴溪, 1744-1833) was famous for leaving Yoshirnasu Todo(吉益東洞) and changing to the 'Zhe Zhong Pai', and in his early years used qing fen(輕粉) to cure geisha(妓女) of syphilis. His argument was "the "Shang Han Lun" must be revered but needs to be adapted", "Zhong jing can be made into a follower but I cannot become his follower", "the later medical texts such as "Ru Men Shi Qin(儒門事親)" should only be used for its prescriptions and not its theories". His works include "Shang Han Lun Yue Yan(傷寒論約言) Third. Nei Teng Xi Zhe(內藤希哲, 1701-1735) learned medicine from Qing Shui Xian Sheng(淸水先生) and went out to Edo. In his book "Yi Jing Jie Huo Lun(醫經解惑論)" he tells of how he went from 'learning'(學) to 'skepticism'(惑) and how skepticism made him learn in 'the six skepticisms'(六惑). In the latter years Xi Zhe(希哲) combines the "Shen Nong Ben Cao jing(神農本草經)", the main text for herbal medicine, "Ming Tang jing(明堂經)" of accupuncture, basic theory texts "Huang Dui Nei jing(黃帝內徑)" and "Nan jing(難經)" with the "Shang Han Za Bing Lun", a book that the 'Gu Fang Pai' saw as opposing to the rest, and became 'an expert of five scriptures'(五經一貫). Part 3. Asada Showhaku(淺田宗伯, 1815-1894) started medicine at Zhong Cun Zhong(中村中倧) and learned 'the old way'(古方) from Yoshirnasu Todo and got experience through Chuan Yue(川越) and Fu jing(福井) and received teachings in texts, history and Wang Yangmin's principles(陽明學) from famous teachers. Showhaku(宗伯) meets a medical official of the makufu(幕府), Ben Kang Zong Yuan(本康宗圓), and recieves help from the 3 great doctors of the Edo period, Taki Motokato(多紀元堅), Xiao Dao Xue GU(小島學古) and Xi Duo Cun Kao Chuang and further develops his arts. At 47 he diagnoses the general Jia Mao(家茂) with 'heart failure from beriberi'(脚氣衝心) and becomes a Zheng Shi(徵I), at 51 he cures a minister from France and received a present from Napoleon, at 65 he becomes the court physician and saves Ming Gong(明宮) jia Ren Qn Wang(嘉仁親王, later the 大正犬皇) from bodily convulsions and becomes 'the vassal of merit who saved the national polity(國體)' At the 7th year of the Meiji(明治) he becomes the 2nd owner of Wen Zhi She(溫知社) and takes part in the 'kampo continuation movement'. In his latter years he saw 14000 patients a year, so we can estimate the quality and quantity of his clinical skills Showhaku(宗伯) wrote over 80 books including the "Ju Chuang Shu Ying(橘窓書影)", "WU Wu Yao Shi Fang Han(勿誤藥室方函)", "Shang Han Biang Shu(傷寒辨術)", "jing Qi Shen Lun(精氣神論)", "Hunag Guo Ming Yi Chuan(皇國名醫傳)" and the "Xian Jhe Yi Hua(先哲醫話)". Especially in the "Ju Chuang Shu Ying(橘窓書影)" he says "the old theories are the main, and the new prescriptions are to be used"(以古法爲主, 後世方爲用), stating the 'Zhe Zhong Pai' way of thinking. In the first volume of "Shung Han Biang Shu(傷寒辨術) and "Za Bing Lun Shi(雜病論識)", 'Zong Ping'(總評), He discerns the parts that are not Zhang Zhong Jing's writings and emphasizes his theories and practical uses.

• Journal of Intelligence and Information Systems
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• v.19 no.1
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• pp.95-110
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• 2013

Recently, the amount of unstructured data being generated through a variety of social media has been increasing rapidly, resulting in the increasing need to collect, store, search for, analyze, and visualize this data. This kind of data cannot be handled appropriately by using the traditional methodologies usually used for analyzing structured data because of its vast volume and unstructured nature. In this situation, many attempts are being made to analyze unstructured data such as text files and log files through various commercial or noncommercial analytical tools. Among the various contemporary issues dealt with in the literature of unstructured text data analysis, the concepts and techniques of opinion mining have been attracting much attention from pioneer researchers and business practitioners. Opinion mining or sentiment analysis refers to a series of processes that analyze participants' opinions, sentiments, evaluations, attitudes, and emotions about selected products, services, organizations, social issues, and so on. In other words, many attempts based on various opinion mining techniques are being made to resolve complicated issues that could not have otherwise been solved by existing traditional approaches. One of the most representative attempts using the opinion mining technique may be the recent research that proposed an intelligent model for predicting the direction of the stock index. This model works mainly on the basis of opinions extracted from an overwhelming number of economic news repots. News content published on various media is obviously a traditional example of unstructured text data. Every day, a large volume of new content is created, digitalized, and subsequently distributed to us via online or offline channels. Many studies have revealed that we make better decisions on political, economic, and social issues by analyzing news and other related information. In this sense, we expect to predict the fluctuation of stock markets partly by analyzing the relationship between economic news reports and the pattern of stock prices. So far, in the literature on opinion mining, most studies including ours have utilized a sentiment dictionary to elicit sentiment polarity or sentiment value from a large number of documents. A sentiment dictionary consists of pairs of selected words and their sentiment values. Sentiment classifiers refer to the dictionary to formulate the sentiment polarity of words, sentences in a document, and the whole document. However, most traditional approaches have common limitations in that they do not consider the flexibility of sentiment polarity, that is, the sentiment polarity or sentiment value of a word is fixed and cannot be changed in a traditional sentiment dictionary. In the real world, however, the sentiment polarity of a word can vary depending on the time, situation, and purpose of the analysis. It can also be contradictory in nature. The flexibility of sentiment polarity motivated us to conduct this study. In this paper, we have stated that sentiment polarity should be assigned, not merely on the basis of the inherent meaning of a word but on the basis of its ad hoc meaning within a particular context. To implement our idea, we presented an intelligent investment decision-support model based on opinion mining that performs the scrapping and parsing of massive volumes of economic news on the web, tags sentiment words, classifies sentiment polarity of the news, and finally predicts the direction of the next day's stock index. In addition, we applied a domain-specific sentiment dictionary instead of a general purpose one to classify each piece of news as either positive or negative. For the purpose of performance evaluation, we performed intensive experiments and investigated the prediction accuracy of our model. For the experiments to predict the direction of the stock index, we gathered and analyzed 1,072 articles about stock markets published by "M" and "E" media between July 2011 and September 2011.

• Journal of Intelligence and Information Systems
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• v.19 no.1
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• pp.35-55
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• 2013

Information technology is a critical resource necessary for any company hoping to support and realize its strategic goals, which contribute to growth promotion and sustainable development. The selection of information technology and its strategic use are imperative for the enhanced performance of every aspect of company management, leading a wide range of companies to have invested continuously in information technology. Despite researchers, managers, and policy makers' keen interest in how information technology contributes to organizational performance, there is uncertainty and debate about the result of information technology investment. In other words, researchers and managers cannot easily identify the independent factors that can impact the investment performance of information technology. This is mainly owing to the fact that many factors, ranging from the internal components of a company, strategies, and external customers, are interconnected with the investment performance of information technology. Using an agent-based simulation technique, this research extracts factors expected to affect investment performance on information technology, simplifies the analyses of their relationship with economic modeling, and examines the performance dependent on changes in the factors. In terms of economic modeling, I expand the model that highlights the way in which product quality moderates the relationship between information technology investments and economic performance (Thatcher and Pingry, 2004) by considering the cost of information technology investment and the demand creation resulting from product quality enhancement. For quality enhancement and its consequences for demand creation, I apply the concept of information quality and decision-maker quality (Raghunathan, 1999). This concept implies that the investment on information technology improves the quality of information, which, in turn, improves decision quality and performance, thus enhancing the level of product or service quality. Additionally, I consider the effect of word of mouth among consumers, which creates new demand for a product or service through the information diffusion effect. This demand creation is analyzed with an agent-based simulation model that is widely used for network analyses. Results show that the investment on information technology enhances the quality of a company's product or service, which indirectly affects the economic performance of that company, particularly with regard to factors such as consumer surplus, company profit, and company productivity. Specifically, when a company makes its initial investment in information technology, the resultant increase in the quality of a company's product or service immediately has a positive effect on consumer surplus, but the investment cost has a negative effect on company productivity and profit. As time goes by, the enhancement of the quality of that company's product or service creates new consumer demand through the information diffusion effect. Finally, the new demand positively affects the company's profit and productivity. In terms of the investment strategy for information technology, this study's results also reveal that the selection of information technology needs to be based on analysis of service and the network effect of customers, and demonstrate that information technology implementation should fit into the company's business strategy. Specifically, if a company seeks the short-term enhancement of company performance, it needs to have a one-shot strategy (making a large investment at one time). On the other hand, if a company seeks a long-term sustainable profit structure, it needs to have a split strategy (making several small investments at different times). The findings from this study make several contributions to the literature. In terms of methodology, the study integrates both economic modeling and simulation technique in order to overcome the limitations of each methodology. It also indicates the mediating effect of product quality on the relationship between information technology and the performance of a company. Finally, it analyzes the effect of information technology investment strategies and information diffusion among consumers on the investment performance of information technology.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.191-202
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• 1995

Purpose: Acute febrile illness in children frequently accompanies with abdominal symptoms such as vomiting, diarrhea, and abdominal pain, even if its etiology is not occured from the gastrointestinal tract. If the etiology of fever was unknown and the fever was accompanied with abdominal symptoms, we should be concerned about whether the etiology of fever was originated from the gastrointestinal tract or interpretated from the abnormality in the gastrointestinal tract. This study was performed to evaluate the diagnostic value of abdominal ultrasonography in patients with fever and abdominal symptoms. Methods: We reviewed retrospectively the medical records of abdominal ultrasonographic (US) findings of 60 cases of acute febrile illness with abdominal symptoms at department of Pediatrics, Ulsan Dongang General Hospital during the period from January 1994 to June 1995. Results: The abnormal abdominal US findings obtained were as follows. 1) The abnormal US findings were seen in 56 cases (93.3%). 2) The most common abnormal US finding was the enlarged mesenteric lymph nodes in 52 cases (86.7%) 3) The enlarged mesenteric lymph nodes with or without intra-abdominal fluid were seen in 30 cases (50.0%) of a wide variety of illnesses, so their diagnostic values were absent. 4) The enlarged mesenteric lymph nodes and splenomegaly with or without ileocecitis were seen in 7 cases. Among them, 4 cases (6.7%) were confirmed as typhoid fever. 5) The US findings in 6 cases of typhoid fever were the enlarged mesenteric lymph nodes in all cases (100%), splenomegaly in 4 cases (66.7%), ileocecitis in 1 case (16.7%), enlarged mesenteric lymph nodes and splenomegaly in 4 cases (66.7%), enlarged mesenteric lymph nodes, splenomegaly and ileocecitis in 1 cases (16.7%). 6) The enlarged mesenteric lymph nodes and the abnormalities around the appendix were seen in 7 cases (11.7%), which were confirmed as appendicitis all. 7) The thickening of wall in urinary bladder was seen in 2 cases (3.3%) of acute cystitis and acute hemorrhagic cystitis. 8) The subtle thickening of wall in colon was seen in 1 cases (1.7%) of shigellosis. Conclusions: The enlarged mesenteric lymph nodes, splenomegaly and ileocolitis on the abdominal ultrasonography in patients with fever and abdominal symptoms aree suggestive findings of typhoid fever. The enlarged mesenteric lymph nodes and the abnormalities around the appendix on abdominal ultrasonography make the rapid diagnosis of acute appendicitis and its complications, when physical examination is difficult in small children and diagnosis of their illnesses is obscure in patients with fever and abdominal pain.