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An Expert System for the Estimation of the Growth Curve Parameters of New Markets (신규시장 성장모형의 모수 추정을 위한 전문가 시스템)

  • Lee, Dongwon;Jung, Yeojin;Jung, Jaekwon;Park, Dohyung
    • Journal of Intelligence and Information Systems
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    • v.21 no.4
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    • pp.17-35
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    • 2015
  • Demand forecasting is the activity of estimating the quantity of a product or service that consumers will purchase for a certain period of time. Developing precise forecasting models are considered important since corporates can make strategic decisions on new markets based on future demand estimated by the models. Many studies have developed market growth curve models, such as Bass, Logistic, Gompertz models, which estimate future demand when a market is in its early stage. Among the models, Bass model, which explains the demand from two types of adopters, innovators and imitators, has been widely used in forecasting. Such models require sufficient demand observations to ensure qualified results. In the beginning of a new market, however, observations are not sufficient for the models to precisely estimate the market's future demand. For this reason, as an alternative, demands guessed from those of most adjacent markets are often used as references in such cases. Reference markets can be those whose products are developed with the same categorical technologies. A market's demand may be expected to have the similar pattern with that of a reference market in case the adoption pattern of a product in the market is determined mainly by the technology related to the product. However, such processes may not always ensure pleasing results because the similarity between markets depends on intuition and/or experience. There are two major drawbacks that human experts cannot effectively handle in this approach. One is the abundance of candidate reference markets to consider, and the other is the difficulty in calculating the similarity between markets. First, there can be too many markets to consider in selecting reference markets. Mostly, markets in the same category in an industrial hierarchy can be reference markets because they are usually based on the similar technologies. However, markets can be classified into different categories even if they are based on the same generic technologies. Therefore, markets in other categories also need to be considered as potential candidates. Next, even domain experts cannot consistently calculate the similarity between markets with their own qualitative standards. The inconsistency implies missing adjacent reference markets, which may lead to the imprecise estimation of future demand. Even though there are no missing reference markets, the new market's parameters can be hardly estimated from the reference markets without quantitative standards. For this reason, this study proposes a case-based expert system that helps experts overcome the drawbacks in discovering referential markets. First, this study proposes the use of Euclidean distance measure to calculate the similarity between markets. Based on their similarities, markets are grouped into clusters. Then, missing markets with the characteristics of the cluster are searched for. Potential candidate reference markets are extracted and recommended to users. After the iteration of these steps, definite reference markets are determined according to the user's selection among those candidates. Then, finally, the new market's parameters are estimated from the reference markets. For this procedure, two techniques are used in the model. One is clustering data mining technique, and the other content-based filtering of recommender systems. The proposed system implemented with those techniques can determine the most adjacent markets based on whether a user accepts candidate markets. Experiments were conducted to validate the usefulness of the system with five ICT experts involved. In the experiments, the experts were given the list of 16 ICT markets whose parameters to be estimated. For each of the markets, the experts estimated its parameters of growth curve models with intuition at first, and then with the system. The comparison of the experiments results show that the estimated parameters are closer when they use the system in comparison with the results when they guessed them without the system.

A Study on Effects of the vocal psychotherapy upon Self-Consciousness (성악심리치료활동을 통한 자기의식 변화에 관한 연구)

  • Lee, Hyun Joo
    • Journal of Music and Human Behavior
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    • v.4 no.2
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    • pp.66-83
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    • 2007
  • The purpose of this study is to learn both effects of the vocal psychotherapy on the self-consciousness and the variety of the self-consciousness on the vocal psychotherapy in return. The research for this study was performed to three subjects who were students of E university, Seoul, ten times for sixty minutes. The subjects were all volunteers for the advertisement on a music-therapy program searching for them on the web site of E university. The vocal psychotherapy program consists of four steps and each of them consists of two to four short terms again. Both before and after the experiment, examinations on self-consciousness were done to recognize the change of the subjects' self-consciousness which would be caused by the vocal psychotherapy activity. After every short term, the subjects were asked to write reports to closely analyze the change of self-consciousness according to the terms and the variety of the subjects. The effect of the vocal psychotherapy activity on the changes of scores in the self-consciousness examination is the first thing to point out on this study. There appeared some personal varieties on the total scores of the examination and scores of some sub-categories. Especially, there were different scores on the private self-consciousness, the public self-consciousness, and the social anxiety between before and after performing the vocal psychotherapy program. Subject A, who had got the best score of all on the scope of the private self-consciousness, showed the steepest decrease on the very scope. On the contrary, the subject showed decrease of scores of the public self-consciousness and the social anxiety in the relatively little rate. Subject B, who had got the highest score of the three on the public self-consciousness, showed the steepest decrease on that of all scopes and showed no difference on the social anxiety scope. In the case of the last one, subject C, who had relatively low scores on the private and public self-consciousness than the others, the private self-consciousness score increased but the public self-consciousness and the social anxiety scores decreased. The changes of the scores of each questions were examined in order to see possible other changes that had not been exposed on the changes of the total and sub-categories scores. As a result of that, of all twenty-eight questions, there were changes about one to two points. Subject A showed the difference with thirteen questions, subject B with sixteen and subject C with nineteen questions. The rate of change of subject C was relatively small but more questions changed and the change of score was wider than the others. Considering all those results, It can be possibly said that the vocal psychotherapy affects the changes of the scores of sub-categories in self-consciousness examination. The next thing to point out on this study is the change of recognition that was exposed on the subjects' report after every short term of the program. As a result of the close analyzing, according to the short terms and variety of self-consciousness, recognizing the way express subjects themselves by voice and recognizing their own voices appeared to be different. How much they cared about others and why they did so were also different. According to the self reports, subject A cared much about her inner thought and emotion and tended to concentrate herself as a social object. There appeared some positive emotional experiments such as emotional abundance and art curiosities on her reports but at the same time some negative emotions such as state-trait anxiety and neuroticism also appeared. Subject B, who showed high scores on the private and public self-consciousness like subject A, had a similar tendency that concentrates on herself as a social object but she showed more social anxiety than subject A. Subject C got relatively lower points in self-consciousness examination, tended to care about herself, and had less negative emotions such as state-trait anxiety than other subjects. Also, with terms going on, she showed changes in the way of caring about her own voice and others. This study has some unique significances in helping people who have problems caused by self-estimation activated with self-consciousness, using voices closely related to one's own self, performing the vocal skills discipline to solve the technical problems. Also, this study has a potentiality that the vocal psychotherapy activity can be effectively used as a way affects the mental health and developing personality.

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Categorizing Quality Features of Franchisees: In the case of Korean Food Service Industry (프랜차이즈 매장 품질요인의 속성분류: 국내 외식업을 중심으로)

  • Byun, Sook-Eun;Cho, Eun-Seong
    • Journal of Distribution Research
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    • v.16 no.1
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    • pp.95-115
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    • 2011
  • Food service is the major part of franchise business in Korea, accounting for 69.9% of the brands in the market. As the food service industry becomes mature, many franchisees have struggled to survive in the market. In general, consumers have higher levels of expectation toward service quality of franchised outlets compared that of (non-franchised) independent ones. They also tend to believe that franchisees deliver standardized service at the uniform food price, regardless of their locations. Such beliefs seem to be important reasons that consumers prefer franchised outlets to independent ones. Nevertheless, few studies examined the impact of qualify features of franchisees on customer satisfaction so far. To this end, this study examined the characteristics of various quality features of franchisees in the food service industry, regarding their relationship with customer satisfaction and dissatisfaction. The quality perception of heavy-users was also compared with that of light-users in order to find insights for developing differentiated marketing strategy for the two segments. Customer satisfaction has been understood as a one-dimensional construct while there are recent studies that insist two-dimensional nature of the construct. In this regard, Kano et al. (1984) suggested to categorize quality features of a product or service into five types, based on their relation to customer satisfaction and dissatisfaction: Must-be quality, Attractive quality, One-dimensional quality, Indifferent quality, and Reverse quality. According to the Kano model, customers are more dissatisfied when Must-be quality(M) are not fulfilled, but their satisfaction does not arise above neutral no matter how fully the quality fulfilled. In comparison, customers are more satisfied with a full provision of Attactive quality(A) but manage to accept its dysfunction. One-dimensional quality(O) results in satisfaction when fulfilled and dissatisfaction when not fulfilled. For Indifferent quality(I), its presence or absence influences neither customer satisfaction nor dissatisfaction. Lastly, Reverse quality(R) refers to the features whose high degree of achievement results in customer dissatisfaction rather than satisfaction. Meanwhile, the basic guidelines of the Kano model have a limitation in that the quality type of each feature is simply determined by calculating the mode statistics. In order to overcome such limitation, the relative importance of each feature on customer satisfaction (Better value; b) and dissatisfaction (Worse value; w) were calculated following the formulas below (Timko, 1993). The Better value indicates how much customer satisfaction is increased by providing the quality feature in question. In contrast, the Worse value indicates how much customer dissatisfaction is decreased by providing the quality feature. Better = (A + O)/(A+O+M+I) Worse = (O+M)/(A+O+M+I)(-1) An on-line survey was performed in order to understand the nature of quality features of franchisees in the food service industry by applying the Kano Model. A total of twenty quality features (refer to the Table 2) were identified as the result of literature review in franchise business and a pre-test with fifty college students in Seoul. The potential respondents of our main survey was limited to the customers who have visited more than two restaurants/stores of the same franchise brand. Survey invitation e-mails were sent out to the panels of a market research company and a total of 257 responses were used for analysis. Following the guidelines of Kano model, each of the twenty quality features was classified into one of the five types based on customers' responses to a set of questions: "(1) how do you feel if the following quality feature is fulfilled in the franchise restaurant that you visit," and "(2) how do you feel if the following quality feature is not fulfilled in the franchise restaurant that you visit." The analyses revealed that customers' dissatisfaction with franchisees is commonly associated with the poor level of cleanliness of the store (w=-0.872), kindness of the staffs(w=-0.890), conveniences such as parking lot and restroom(w=-0.669), and expertise of the staffs(w=-0.492). Such quality features were categorized as Must-be quality in this study. While standardization or uniformity across franchisees has been emphasized in franchise business, this study found that consumers are interested only in uniformity of price across franchisees(w=-0.608), but not interested in standardizations of menu items, interior designs, customer service procedures, and food tastes. Customers appeared to be more satisfied when the franchise brand has promotional events such as giveaways(b=0.767), good accessibility(b=0.699), customer loyalty programs(b=0.659), award winning history(b=0.641), and outlets in the overseas market(b=0.506). The results are summarized in a matrix form in Table 1. Better(b) and Worse(w) index indicate relative importance of each quality feature on customer satisfaction and dissatisfaction, respectively. Meanwhile, there were differences in perceiving the quality features between light users and heavy users of any specific franchise brand in the food service industry. Expertise of the staffs was labeled as Must-be quality for heavy users but Indifferent quality for light users. Light users seemed indifferent to overseas expansion of the brand and offering new menu items on a regular basis, while heavy users appeared to perceive them as Attractive quality. Such difference may come from their different levels of involvement when they eat out. The results are shown in Table 2. The findings of this study help practitioners understand the quality features they need to focus on to strengthen the competitive power in the food service market. Above all, removing the factors that cause customer dissatisfaction seems to be the most critical for franchisees. To retain loyal customers of the franchise brand, it is also recommended for franchisor to invest resources in the development of new menu items as well as training programs for the staffs. Lastly, if resources allow, promotional events, loyalty programs, overseas expansion, award-winning history can be considered as tools for attracting more customers to the business.

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Study the Analysis of Comparison with AROI and MROI Mode in Gated Cardiac Blood Pool Scan (게이트심장혈액풀 스캔에서 자동 관심영역 설정과 수동 관심영역 설정 모드의 비교 분석에 관한 고찰)

  • Kim, Jung-Yul;Kang, Chun-Koo;Kim, Yung-Jae;Park, Hoon-Hee;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.12 no.3
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    • pp.222-228
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    • 2008
  • Purpose: The objectives of this study were to compare the left ventricle ejection fraction (LVEF) from gated cardiac blood pool scan (GCBP) for analysis auto-drawing region of interest mode (AROI) and manual-drawing region of interest mode (MROI), respectively. To evaluation the relationships between values produced by both ROI modes. Materials and Methods: Gated cardiac blood pool scan using in vivo method Tc-99m Red Blood Cell were performed for 33 patients (mean age: $53.2{\pm}13.2\;y$) with objective of chemotherapy using single head gamma camera (ADAC Laboratories, Milpitas, CA). Left ventricular ejection fraction was automatically and manually measured, respectively. Results: There was significant difference statistically between AROI and MROI ($LVEF^{AROI}$: $71.4{\pm}12.4%$ vs. $LVEF^{MROI}$: $65.8{\pm}5.9%$, p=0.003). Intra-observer agreements in AROI was higher than MROI ($\gamma^{AROI}=0.964$, Cronbach's $\alpha^{AROI}=0.986$ vs. $\gamma^{MROI}=0.793$, Cronbach's $\alpha^{MROI}=0.911$), either. Additionally, there was no significant difference statistically at best septal view (${\Delta}LVEF^{BSV}=0.7{\pm}2.3%$, p=0.233), however statistically significant difference was found at badly separated septal view (${\Delta}LVEF=10.9{\pm}11.4%$, p=0.001). Moreover, Intra-observer agreements in best septal view was higher than badly separated septal view ($\gamma^{BSV}=0.939$, Cronbach's $\alpha^{BSV}=0.978$; $\gamma=0.948$, Cronbach's $\alpha=0.981$ at AROI, $\gamma^{BSV}=0.836$, Cronbach's $\alpha^{BSV}=0.936$; $\gamma=0.748$, Cronbach's $\alpha=0.888$ at MROI). Conclusion: When best septal view was acquired, LVEF by AROI and MROI indicated not different. Comparing Intra-observer agreements with AROI and MROI, the AROI tended to show higher. Therefore, it is considered that the AROI than MROI is valuable in reproducibility and objective when ROI analysis by acquire left ventricular of best septal view.

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A THREE-DIMENSIONAL FEM COMPARISON STUDY ABOUT THE FORCE, DISPLACEMENT AND INITIAL STRESS DISTRIBUTION ON THE MAXILLARY FIRST MOLARS BY THE APPLICATION OF VAR10US ASYMMETRIC HEAD-GEAR (비대칭 헤드기어의 적용시 상악제 1 대구치에 나타나는힘과 변위 및 초기 응력분포에 관한 3차원 유한요소법적 연구)

  • Kim, Jong-Soo;Cha, Dyung-Suk;Ju, Jin-Won;Lee, Jin-Woo
    • The korean journal of orthodontics
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    • v.31 no.1 s.84
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    • pp.25-38
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    • 2001
  • The purpose of this study was to compare the force, the displacement and the stress distribution on the maxillary first molars altered by the application of various asymmetric head-gear. For this study, the finite element models of unilateral Cl II maxillary dental arch was made. Also, the finite element models of asymmetric face-bow was made. Three types of asymmetric face-bow were made : each of the right side 15mm, 25mm and 35mm shorter than the left side. We compared the forces, the displacement and the distribution of stress that were generated by application of various asymmetric head-gear, The results were as follows. 1. The total forces that both maxillary first molars received were similar in all groups. But the forces that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow shortened. 2. In lateral force comparison, the buccal forces that normally positioned tooth received were increased as the length of the outer-bow shortened, and the buccal fortes that mesially positioned tooth received were decreased as the length of the outer-bow shortened. Though the net lateral force moved to the buccal side of normally positioned tooth as the length of the outer-bow shortened, both maxillary first molars received the buccal force. That showed 'Avchiai Expansion Effect' 3. The distal forces, the extrusion forces and the magnitudes of the crown distal tipping that mesially positioned tooth received were increased as the length of the outer-bow shortened, and the forces that normally positioned tooth received were decreased as the length of the outer-bow was shortened. 4. The magnitude of the distal-in rotation that normally positioned tooth received were increased as the length of the outer-bow was shortened. But, mesially positioned tooth show two different results. For the outer-bow 15mm shortened, mesially positioned tooth showed the distal-in rotation, hut for the outer-bow 25mm and 35mn shortened, mesially positioned tooth showed the distal-out rotation. Thus, the turning point exists between 15mm and 25mm. 5. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the compressive stress in the distobuccal root of the normally positioned tooth moved from the palatal side to the distal side and the buccal side successively as the length of the outer-bow shortened. 6. This study of the initial stress distribution of the periodontal ligament at slightly inferior of the furcation area revealed that the magnitudes of stress were altered but the total stress distributions were not altered in the mesiobuccal root and the palatal root of normally positioned tooth, and also three roots of mesially positioned tooth as the length of the outer-bow shortened.

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A STUDY ON THE RELATIONS OF VARIOUS PARTS OF THE PALATE FOR PRIMARY AND PERMANENT DENTITION (유치열과 영구치열의 구개 각부의 관계에 관한 연구)

  • Lee, Yong-Hoon;Yang, Yeon-Mi;Lee, Yong-Hee;Kim, Sang-Hoon;Kim, Jae-Gon;Baik, Byeong-Ju
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.4
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    • pp.569-578
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    • 2004
  • The purpose of this study was to clarify the palatal arch length, width and height in the primary and permanent dentition. Samples were consisted of normal occlusions both in the primary dentition(50 males and 50 females) and in the permanent dentition(50 males and 50 females). With their upper plaster casts were used and through 3-dimensional laser scanning(3D Scanner, DS4060, LDI, U.S.A.), cloud data, polygonization, section curve and loft surface, fit and horizontal plane were based to measure the palatal arch length, width and height(Surfacer 10.0, Imageware, U.S.A.). T-tests were applied for the statistical analyze of the data. The results were as follows : 1. In the measurement values, the values of the male were higher than those of the female except primary anterior palatal height. There were not only statistically significant differences in anterior palatal width(p<0.05) and posterior palatal width(p<0.01) in primary dentition but palatal width(p<0.05), anterior palatal length(p<0.01), middle and posterior palatal length(p<0.05) in permanent dentition between male and female. 2. In the indices of palate, there were statistically significant differences in height-length index(p<0.05) and width-length index(p<0.01) between male and female in primary dentition. In permanent dentition, there was statistically difference between male and female. 3. In the measurement values, posterior palatal width was increased most greatly. Posterior palatal height, anterior palatal width and anterior palatal length were followed by descending order. On the other hand, anterior palatal height and posterior palatal length were decreased. 4. In the indices of palate, the height-length index, the width-length index and posterior height-width index were increased, but the others were decreased.

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Testing for Measurement Invariance of Fashion Brand Equity (패션브랜드 자산 측정모델의 등치테스트에 관한 연구)

  • Kim Haejung;Lim Sook Ja;Crutsinger Christy;Knight Dee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.28 no.12 s.138
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    • pp.1583-1595
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    • 2004
  • Simon and Sullivan(l993) estimated that clothing and textile related brand equity had the highest magnitude comparing any other industry category. It reflects that fashion brands reinforce the symbolic, social values and emotional characteristics being different from generic brands. Recently, Kim and Lim(2002) developed a fashion brand equity scale to measure a brand's psychometric properties. However, they suggested that additional psychometric tests were needed to compare the relative magnitude of each brand's equity. The purpose of this study was to recognize the psychometric constructs of fashion brand equity and validate Kim and Lim's fashion brand equity scale using the measurement invariance test of cross-group comparison. First, we identified the constructs of fashion brand equity using confirmatory factor analysis through structural equation modeling. Second, we compared the relative magnitude of two brands' equity using the measurement invariance test of multi-group simultaneous factor analysis. Data were collected at six major universities in Seoul, Korea. There were 696 usable surveys for data analysis. The results showed that fashion brand equity was comprised of 16 items representing six dimensions: customer-brand resonance, customer feeling, customer judgment, brand imagery, brand performance and brand awareness. Also, we could support the measurement invariance of two brands' equities by configural and metric invariance tests. There were significant differences in five constructs' mean values. The greatest difference was in customer feeling; the smallest, in customer judgment.

Effects of Shoulder Muscle Strength on Terminal Range by Humeral Head Retroversion (상완골 후경각이 가동역에 따른 견관절 근력에 미치는 영향)

  • Park, Si-Young;Lee, Dong-Jun
    • Journal of Life Science
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    • v.20 no.4
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    • pp.549-554
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    • 2010
  • Increased external rotation and decreased internal rotation have been noted to occur progressively in the throwing shoulders of baseball pitchers. The purpose of this study was to provide descriptive data for terminal range eccentric antagonist/concentric agonist shoulder muscle strength in collegiate baseball pitchers with humeral head retroversion diagnosed through MRI. The dominant and non-dominant shoulders of 9 asymptomatic baseball pitchers were tested through a range of 20 degrees of external rotation to 90 degrees of internal rotation using the Biodex system 3 isokinetic dynamometer at speeds of $90^{\circ}/s$ and $180^{\circ}/s$. Differences between the dominant and non-dominant shoulders were assessed using the paired samples t-test. Total range of motion, measured at $90^{\circ}$ of glenohumeral abduction, was $180.1^{\circ}$ for dominant shoulders and $183.7^{\circ}$ for non-dominant shoulders. Humeral head retroversion measured $47.6{\pm}6.1^{\circ}$ in dominant and $37.8{\pm}5.3^{\circ}$ in non-dominant extremities. The mean internal rotator concentric contraction (IR-Con) showed a significant difference compared to $31.5{\pm}5.1$ (Nm) in dominant and $38.7{\pm}5.2$ (Nm) in non-dominant shoulders at $180^{\circ}/s$ (p<0.05). The mean external rotator eccentric contraction (ER-Ecc) showed a significant difference compared to $20.3{\pm}4.7$ (Nm) in dominant and $25.1{\pm}3.7$ (Nm) in non-dominant shoulders at $90^{\circ}/s$ (p<0.05). There is a pattern of increased external rotation and decreased internal rotation in the dominant extremity that significantly correlates with an increase in humeral retroversion.

Short-term Clinical Experience on Interferon gamma-1b Therapy for Idiopathic Pulmonary Fibrosis (특발성 폐섬유화증에서 Interferon gamma-1b 치료의 단기 임상경험)

  • Hwang, Jung Hye;Chung, Man Pyo;Kang, Eun Hae;Kim, Kyung Chan;Lee, Byoung-Hoon;Koh, Won-Jung;Suh, Gee Young;Kim, Hojoong;Lee, Kyung Soo;Han, Joungho;Kwon, O Jung
    • Tuberculosis and Respiratory Diseases
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    • v.56 no.6
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    • pp.619-627
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    • 2004
  • Background : Corticosteroids in combination with cytotoxic drugs are the mainstays of therapy for idiopathic pulmonary fibrosis (IPF). However, there has been no regimen showing any survival benefit. The aim of this study was to describe a short-term clinical experience on interferon gamma-1b (IFN-${\gamma}1b$) therapy for IPF, as an antifibrotic agent. Methods : Medical records of 27 patients who were treated with IFN-${\gamma}1b$ (2 million IU, 3 times a week, subcutaneous injection) were retrospectively reviewed. Treatment response was assessed using ATS/ERS criteria in 17 patients who received IFN-${\gamma}1b$ for more than 6 months. In addition, we compared the efficacy of IFN-${\gamma}1b$ therapy with that of cyclophosphamide${\pm}$prednisolone therapy (n=26). Results : The median age of IFN-${\gamma}$ treated group (M:F=19:8) was 59 years (44-74 years). Compared to the patients who showed a stable response at 6 months (n=12), the deteriorated group (n=5) had worse baseline lung function (FVC, $55.4{\pm}11.3%$ vs. $70.7{\pm}10.9%$, p=0.019; DLco, $50.3{\pm}7.3%$ vs. $76.9{\pm}19.6%$, p=0.014). Lower baseline $PaO_2$ on room air breathing was observed in the deteriorated group ($68.6{\pm}7.8mmHg$ vs. $91.4{\pm}6.6mmHg$ p=0.001). Subcutaneous IFN-${\gamma}1b$ did not show better efficacy than prednisolone. Five patients discontinued IFN-${\gamma}$ because of severe side effects. ARDS developed in one patient, who eventually died. Conclusion : The administration of IFN-${\gamma}1b$ is not desirable for patients diagnosed with IPF with poor lung function. Long-term and large-scaled clinical studies are needed for its efficacy in IPF.

Behavioural Analysis of Password Authentication and Countermeasure to Phishing Attacks - from User Experience and HCI Perspectives (사용자의 패스워드 인증 행위 분석 및 피싱 공격시 대응방안 - 사용자 경험 및 HCI의 관점에서)

  • Ryu, Hong Ryeol;Hong, Moses;Kwon, Taekyoung
    • Journal of Internet Computing and Services
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    • v.15 no.3
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    • pp.79-90
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    • 2014
  • User authentication based on ID and PW has been widely used. As the Internet has become a growing part of people' lives, input times of ID/PW have been increased for a variety of services. People have already learned enough to perform the authentication procedure and have entered ID/PW while ones are unconscious. This is referred to as the adaptive unconscious, a set of mental processes incoming information and producing judgements and behaviors without our conscious awareness and within a second. Most people have joined up for various websites with a small number of IDs/PWs, because they relied on their memory for managing IDs/PWs. Human memory decays with the passing of time and knowledges in human memory tend to interfere with each other. For that reason, there is the potential for people to enter an invalid ID/PW. Therefore, these characteristics above mentioned regarding of user authentication with ID/PW can lead to human vulnerabilities: people use a few PWs for various websites, manage IDs/PWs depending on their memory, and enter ID/PW unconsciously. Based on the vulnerability of human factors, a variety of information leakage attacks such as phishing and pharming attacks have been increasing exponentially. In the past, information leakage attacks exploited vulnerabilities of hardware, operating system, software and so on. However, most of current attacks tend to exploit the vulnerabilities of the human factors. These attacks based on the vulnerability of the human factor are called social-engineering attacks. Recently, malicious social-engineering technique such as phishing and pharming attacks is one of the biggest security problems. Phishing is an attack of attempting to obtain valuable information such as ID/PW and pharming is an attack intended to steal personal data by redirecting a website's traffic to a fraudulent copy of a legitimate website. Screens of fraudulent copies used for both phishing and pharming attacks are almost identical to those of legitimate websites, and even the pharming can include the deceptive URL address. Therefore, without the supports of prevention and detection techniques such as vaccines and reputation system, it is difficult for users to determine intuitively whether the site is the phishing and pharming sites or legitimate site. The previous researches in terms of phishing and pharming attacks have mainly studied on technical solutions. In this paper, we focus on human behaviour when users are confronted by phishing and pharming attacks without knowing them. We conducted an attack experiment in order to find out how many IDs/PWs are leaked from pharming and phishing attack. We firstly configured the experimental settings in the same condition of phishing and pharming attacks and build a phishing site for the experiment. We then recruited 64 voluntary participants and asked them to log in our experimental site. For each participant, we conducted a questionnaire survey with regard to the experiment. Through the attack experiment and survey, we observed whether their password are leaked out when logging in the experimental phishing site, and how many different passwords are leaked among the total number of passwords of each participant. Consequently, we found out that most participants unconsciously logged in the site and the ID/PW management dependent on human memory caused the leakage of multiple passwords. The user should actively utilize repudiation systems and the service provider with online site should support prevention techniques that the user can intuitively determined whether the site is phishing.