• Journal of Global Scholars of Marketing Science
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• v.18 no.2
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• pp.223-252
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• 2008

In this study, we attempt to propose a choice-based diffusion model with switching cost, which can be used to forecast the dynamic substitution and competition among previous and new products at both individual-level and aggregate level, especially when market data for new products is insufficient. Additionally, we apply the proposed model to the empirical case of substitution and competition among Analog Cable TV that represents previous fixed charged broadcasting service and Digital Cable TV and Internet Protocol TV (IPTV) that are new ones, verify the validities of our proposed model, and finally derive related empirical implications. For empirical application, we obtained data from survey conducted as follows. Survey was administered by Dongseo Research to 1,000 adults aging from 20 to 60 living in Seoul, Korea, in May of 2007, under the title of 'Demand analysis of next generation fixed interactive broadcasting services'. Conjoint survey modified as follows, was used. First, as the traditional approach in conjoint analysis, we extracted 16 hypothetical alternative cards from the orthogonal design using important attributes and levels of next generation interactive broadcasting services which were determined by previous literature review and experts' comments. Again, we divided 16 conjoint cards into 4 groups, and thus composed 4 choice sets with 4 alternatives each. Therefore, each respondent faces 4 different hypothetical choice situations. In addition to this, we added two ways of modification. First, we asked the respondents to include the status-quo broadcasting services they subscribe to, as another alternative in each choice set. As a result, respondents choose the most preferred alternative among 5 alternatives consisting of 1 alternative with current subscription and 4 hypothetical alternatives in 4 choice sets. Modification of traditional conjoint survey in this way enabled us to estimate the factors related to switching cost or switching threshold in addition to the effects of attributes. Also, by using both revealed preference data(1 alternative with current subscription) and stated preference data (4 hypothetical alternatives), additional advantages in terms of the estimation properties and more conservative and realistic forecast, can be achieved. Second, we asked the respondents to choose the most preferred alternative while considering their expected adoption timing or switching timing. Respondents are asked to report their expected adoption or switching timing among 14 half-year points after the introduction of next generation broadcasting services. As a result, for each respondent, 14 observations with 5 alternatives for each period, are obtained, which results in panel-type data. Finally, this panel-type data consisting of $4{\ast}14{\ast}1000=56000$observations is used for estimation of the individual-level consumer adoption model. From the results obtained by empirical application, in case of forecasting the demand of new products without considering existence of previous product(s) and(or) switching cost factors, it is found that overestimated speed of diffusion at introductory stage or distorted predictions can be obtained, and as such, validities of our proposed model in which both existence of previous products and switching cost factors are properly considered, are verified. Also, it is found that proposed model can produce flexible patterns of market evolution depending on the degree of the effects of consumer preferences for the attributes of the alternatives on individual-level state transition, rather than following S-shaped curve assumed a priori. Empirically, it is found that in various scenarios with diverse combinations of prices, IPTV is more likely to take advantageous positions over Digital Cable TV in obtaining subscribers. Meanwhile, despite inferiorities in many technological attributes, Analog Cable TV, which is regarded as previous product in our analysis, is likely to be substituted by new services gradually rather than abruptly thanks to the advantage in low service charge and existence of high switching cost in fixed charged broadcasting service market.

• Journal of Global Scholars of Marketing Science
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• v.18 no.2
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• pp.65-88
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• 2008

Since the implementation of economic reforms in 1978, the Chinese economy grows rapidly at an average annul growth rate of 9% over the post two decades. Franchising has been widely recognized as an important source of entrepreneurial activity. Trust is important in that it facilitates relational exchanges by permits partners to transcend short-run inequities or risks to concentrate on long-term profits or gains. In the relationship between the franchisors and franchisees, trust has been described as an important source of competitive advantage. However, little research has been done on the factors affecting trust in Chinese franchisor-franchisee relationships. The purpose of this study is to investigate what factors affect the trust in the franchise system in China, and to provide guidelines and insights to franchisors which enter Chinese market. In this study, according to Morgan and Hunt (1994), trust is defined as the extending when one party has confidence in an exchange partner's reliability and integrity. We offered a conceptual model of the empirical study. The model shows that the factors affecting the trust include franchisor's supports, communication, satisfaction with previous outcome and conflict. We also suggested the franchisor's supports and communication like to enhance the franchisee's satisfaction with previous outcome, and the franchisor's supports, communication and he franchisee's satisfaction with previous outcome tend to decrease conflict. Before the formal study, a pretest involving exploratory interviews with owners from three franchisees was conducted to make sure the questionnaire was relevant and clear to the respondents. The data were collected using trained interviewers to carry out personal interviews with the aid of an unidentified, muti-page, structured questionnaire. The respondents comprised of owners, managers, and owner managers of franchisee-owned food service franchises located in Beijing, China. Even though a total of 256 potential franchises were initially contacted, the finally usable sample consisted of 125 respondents. As expected, the sampling method was successful in soliciting respondents with waried personal and firm characteristics. Self-administrated questionnaires were used for all measures. And established scales were used to measure the latent constructs in this study. The measures tapped the franchisees' perceptions of the relationship with the referent franchisor. Five-point Likert-type scales ranging from "strongly disagree" (=1) to "strongly agree" (=7) were used throughout the constructs (trust, eight items; support, five items; communication, four items; satisfaction, six items; conflict, three items). The reliability measurements traditionally employed, such as the Cronbach's alpha, were used. All the reliabilities were greater than.80. The proposed measurement model was estimated using SPSS 12.0 and AMOS 5.0 analysis package. We conducted A series of exploratory factor analyses and confirmatory factor analyses to assess the convergent validity, discriminant validity, and reliability. The results indicate reasonable overall fits between the model and the observed data. The overall fit of measurement model were $X^2$= 159.699, p=0.004, d.f. = 116, GFI =.879, NFI =.898, CFI =.969, IFI =.970, TLI =.959, RMR =.058. The results demonstrated that the data reasonably fitted the model. We also examined construct reliability and reliability and average variance extracted (AVE). The construct reliability of each construct was greater than.80 and the AVE of each construct was greater than.50. According to the analysis of Structure Equation Modeling (SEM), the results of path model indicated an adequate fit of the model: $X^2$= 142.126, p = 0.044, d.f. = 115, GFI =.892, NFI =.909, CFI =.981, IFI =.981, TLI =.974, RMR =.057. As hypothesized, the results showed that it is strategically important to establish trust in a franchise system, and the franchisor's supports, communication and satisfaction with previous outcome tend to reinforce franchisee's trust. The results also showed trust seems to decrease as the experience of conflict episodes increases. And we also noticed that franchisor's supports and communication tend to enhance the franchisee's satisfaction with previous outcome, and communication tend to decrease conflict. If the trust between the franchisor and franchisee can be established in a franchise system, franchising offers many benefits and reduces many costs. To manage a mutual trust of relationship with their franchisees, franchisor's should provide support effectively to their franchisees. Effective assistant services have direct effect on franchisees' satisfaction with previous outcome and trust in franchisor. Especially, franchise sales process, orientation, and training in the start-up period are key elements for success of the franchise system. Franchisor's support is an accumulated separate satisfaction evaluation with different kind of service provided by the franchisor. And providing support definitely can improve the trustworthy image of the franchisor. In the franchise system, conflicts of interests and exertions of different power sources are very common. The experience of conflict episodes seems to negatively relate to trust. Therefore, it is important to reduce the negative side of the relationship conflicts. Communication actually plays a broader role in reducing conflict and establish mutual trust in franchisor-franchisee relationship. And effective communication between franchisors and franchisees can improve franchisees' satisfaction toward the franchise system. As the diversification of Chinese markets, both franchisors and franchisees must keep the relevant, timely, and reliable communication. And it is very important to improve the quality of communication. Satisfaction with precious outcomes seems to positively relate to trust. Franchisors and franchisees that are highly satisfied with the previous outcomes that flow from their relationship will perceive their partner as advancing their goal achievement. Therefore, it is necessary for both franchisor and their franchisees to make the welfare of partner with effort. Little literature has focused on what factors affect the trust between franchisors and their franchisees in China. This study developed the hypotheses regarding the factors affecting trust in the transaction relationship. The results of data analysis supported the hypotheses strongly. There are certain limitations in this study. First, we may point out that some other factors missed in this study could be significantly important. Second, the context of this study, food service industry, limits its potential generalizability for all franchise systems. More studies in different categories of franchise system are needed to broaden its generalizability. Third, the model was tested empirically in a sample in Beijing, more empirical tests of the proposed model in other Chinese areas are needed. Finally, the analysis in this study was solely based on the perception of franchisees and the opinions of franchisors were not included.

• Journal of Oral Medicine and Pain
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• v.32 no.4
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• pp.441-447
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• 2007

Internal derangement of the temporomandibular joint(TMJ) is defined as an abnormal relationship of the articular disc to the condyle. Mandibular manipulation is one of the conservative treatments to be considered first to manage the patients with anterior disc displacement without reduction. Mandibular manipulation is used to increase articular mobility and to restore the displaced disc into an anatomically normal position. While Farrar's technique has been popularly used, Minagi et al., Mongini and Suarez introduced the manipulation technique conducted by the patients themselves. But there is no study on the efficacy of self-manipulation technique, comparing with conventional one. The aim of this study was to investigate the efficacy of the conventional and self-manipulation technique, which was modified to complement the previously described technique by Minagi et al., in the treatment of patients with anterior disc displacement without reduction. TMD patients, who visited Department of Oral Medicine of Seoul National University Dental Hospital from December, 2002 to November, 2004 and were diagnosed as anterior disc displacement without reduction by TMJ magnetic resonance imaging (MRI) were enrolled. Conservative treatments including physical therapy, exercise, behavioral therapy, stabilization splint therapy, and manipulation therapy were done to every single patient until the symptomsimproved enough to discharge the patient. The charts were reviewed retrospectively according to the type of manipulation. In the results, patients whose maximum mouth opening was more than 40 mm was higher in the self-manipulation group(69.9%) than in the conventional manipulation group(42.9%). But difference between two groups was not significant. According to the fact that we decided to discharge the patients whentheir mouth opening increased to more than 40 mm and subjective symptoms such as pain and discomfort were improved as well, treatment period of discharged patients was significantly shorter in the self-manipulation group($29.2{\pm}12.3$ weeks) than in the conventional manipulation group ($61.0{\pm}38.0$ weeks) (p<0.01). In conclusion, in the treatment of TMD patients with anterior disc displacement without reduction, the self-manipulation technique which is performed by patients themselves is an effective treatment modality for increasing the range of mouth opening and shortening the total treatment period.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.3
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• pp.239-249
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• 2001

The purpose of this study is to evaluate the relationship of the factors which could be influenced by orthognathic surgery especillay SSRO. We measured the amounts of the maximum opening, lateral movements, maximum velocity and pattern of mandibular path during the opening and closing of mandible at the following times ; preoperative, 1 month after operation, 6 months after operation respectively using MKG. And the results were compared according to the categorized subgroups. Following results were obtained : 1. The change of the amounts of mandibular lateral movement and maximum opening velocity were statistically different between male and female (p<0.05), but the others were not. 2. According to the method of operation, there was no difference in the change of the mandibular movements between the group of SSRO and SSRO plus LeFort I osteotomy (p>0.05). 3. According to the amounts of mandibular movement, the recovery of left lateral movement of the group of $6{\sim}10mm$ was better than the other groups (p<0.05). 4. In the frontal pattern of the opening and closing of the mandible, the complex deflected type (F5), simple deflected type (F4), complex deviated type (F3), simple deviated type (F2), straight type (F1) were obtained in order at the time of preoperative, simple deflected type, simple deviated type, complex deviated type, straight type, complex deflected type in order at the time of 1 month after surgery, and the result at the time of 6 months after surgery was the same with that of the time of preoperative. In the sagittal pattern, non-coincident type (S2) was predominant at the time of preoperative, and coincident type (S1) was predominant at the time of 1 month after surgery. After 6 months, the result was also the same with that of the preoperative in sagittal pattern. 5. There was not a statistical difference in the change of the mandibular movement between group of presence of the preoperative TMJ symptoms and non-presence group (p>0.05). 6. There was not a statistical difference in the change of the mandibular movement between repositioning device applied group and non-applied group (p>0.05). 7. Sixty three percents of the patients who had preoperative TMJ symptoms were improved after surgery and preoperative TMJ symptoms were more improved after operation in the repositioning device non-applied group statistically (p<0.05).

• Journal of Nutrition and Health
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• v.49 no.3
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• pp.165-178
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• 2016

Purpose: This study was performed to examine associations of intakes of milk and dairy products, pulses, and soy foods with bone health in Koreans aged 50 yr and older. Methods: A total of 3,201 men and 3,581 women aged 50 yr and older who participated in the 2008~2011 Korea National Health and Nutrition Examination Survey were grouped by sex and age groups of 50~64 yr and 65 yr and older. Subjects within each sex and age group were divided into three bone health groups: normal, osteopenia, and osteoporosis groups based on bone mineral density. Intakes of nutrients and foods derived from 24-hour recall data were compared among three bone health groups. Associations between intake frequencies of foods, including milk, yogurt, tofu, or soy milk, and osteoporosis risk were evaluated based on confounding risk factor-adjusted logistic regression. Results: Calcium intake was in the order of normal, osteopenia, and osteoporosis in men (p < 0.01) and women (p < 0.05) aged 50~64 yr as well as in men aged 65 yr and older (p < 0.001). In women aged 50~64 yr, intake of milk and dairy products was lower in the osteoporosis group (p < 0.01) as compared with the osteopenia group. Intake of pulses or tofu was not significantly different among bone health groups. Odds ratio (OR) for milk intake frequency (${\geq}2$ times/week) compared to intake frequency less than 1 time/month was 0.45 (95% CI 0.24~0.85, p for trend = 0.022) in men aged 65 yr and older. The OR for yogurt intake frequency (1 time/month~1 time/week) was 0.47 (95% CI 0.30~0.73, p for trend = 0.019) in women aged 50~64 yr. Intake frequency of tofu or soy milk was not associated with reduced risk of osteoporosis in all groups. Conclusion: Dairy food intake was significantly associated with bone health, and its effect was sex- and age group-specific, whereas soy food intake was not. Dietary intervention to prevent osteoporosis would be effective for women aged 50~64 yr old and for men aged 65 yr and older.

• Progress in Medical Physics
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• v.18 no.2
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• pp.81-86
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• 2007

The cone-beam CT (CBCT) which is acquired using on-board imager (OBI) attached to a linear accelerator is widely used for the image guided radiation therapy. In this study, the effect of respiratory motion on the quality of CBCT image was evaluated. A phantom system was constructed in order to simulate respiratory motion. One part of the system is composed of a moving plate and a motor driving component which can control the motional cycle and motional range. The other part is solid water phantom containing a small cubic phantom ($2{\times}2{\times}2cm^3$) surrounded by air which simulate a small tumor volume in the lung air cavity CBCT images of the phantom were acquired in 20 different cases and compared with the image in the static status. The 20 different cases are constituted with 4 different motional ranges (0.7 cm, 1.6 cm, 2.4 cm, 3.1 cm) and 5 different motional cycles (2, 3, 4, 5, 6 sec). The difference of CT number in the coronal image was evaluated as a deformation degree of image quality. The relative average pixel intensity values as a compared CT number of static CBCT image were 71.07% at 0.7 cm motional range, 48.88% at 1.6 cm motional range, 30.60% at 2.4 cm motional range, 17.38% at 3.1 cm motional range The tumor phantom sizes which were defined as the length with different CT number compared with air were increased as the increase of motional range (2.1 cm: no motion, 2.66 cm: 0.7 cm motion, 3.06 cm: 1.6 cm motion, 3.62 cm: 2.4 cm motion, 4.04 cm: 3.1 cm motion). This study shows that respiratory motion in the region of inhomogeneous structures can degrade the image quality of CBCT and it must be considered in the process of setup error correction using CBCT images.

• Clinical and Experimental Pediatrics
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• v.45 no.12
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• pp.1519-1527
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• 2002

Purpose : Although influenza virus is one of the most important causes of acute respiratory tract infections(ARTIs) in children, virus isolation is not popular and there are only a few clinical studies on influenza in Korea. We evaluated the epidemiologic and clinical features of ARTIs by influenza virus in children. Methods : From February 1995 to August 2001, nasopharyngeal aspirations were obtained and cultured for the isolation of influenza virus in children admitted with ARTIs. The medical records of patients with influenza virus infection were reviewed retrospectively. Results : Respiratory viruses were isolated in 997(22.0%) out of 4,533 patients examined, and influenza virus was isolated in 164 cases(3.6%). Influenza virus was isolated year after year mainly from December to April of next year. The ratio of male and female was 1.9 : 1 with a median age of 15 months. The most common clinical diagnosis of influenza virus infection was pneumonia, and fever and cough developed in most patients. There was no difference between influenza A and B infection in clinical diagnoses and symptoms. All patients recovered without receiving antiviral treatment except for one patient diagnosed with pneumonia who had underlying disease of Down syndrome with ventricular septal defect. Conclusion : ARTIs caused by influenza virus developed every winter and spring during the period of study. Because fatal complication can develop in the high risk group, prevention, early diagnosis and proper management of influenza should be emphasized.

• Korean Journal of Psychosomatic Medicine
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• v.11 no.2
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• pp.137-148
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• 2003

Introduction: This research was performed to contract the attitude of dietary restriction and the psychological problems such as depressive mood and perceived stress and to investigate the relationship of these and obesity in women who visited the obesity clinic. Methods: During May 2001, sociodemographic variables, physical characteristics, Three Factor Eating Questionnaire(TFEQ), Symptom Check List-90-R(SCL-90-R) and Perceived Stress Scale were assessed from 150 female who visited the obesity clinics which were located at downtown, Seoul and the Hospital of Ajou University, Medical College. Hamilton depression rating scale(HDRS) was estimated by author. And then 116 female cases who filled up the questionnaire faithfully were included. Results: Obese group more than Body Mass Index(BMI) $25.0kg/m^2$ was 50% of the total subjects. BMI was increased as the age goes up(p<0.001). The frequency of unmarried cases in the under normal weight group was high rate of 48.8% while it in the obese group was 13.8%(p<0.001). There was no significant difference in the rate of smoking and alcohol drinking among subjects by BMI. There was no significant difference of TFEQ among subjects by BMI and the percent of body fat. Factor 2(r=0.27, p<0.01) and Factor 3(r=0.24, p<0.01) were significantly correlated with Global Severity Index(GSI). Only the paranoia scale among each estimated mean value of T scores of SCL-90-R by BMI was the significant difference between the overweight group and the obese group(p<0.05). T scores of scales of SCL-90-R were less than 50, but T scores of the under normal weight group and the obese group were higher than overweight group. GSI was significantly correlated with HDRS(r=0.75, p<0.01) and Perceived Stress Scale(r=0.32, p<0.01). Depressive mood in the obese group was significantly higher than non-obese group that HDRS was compared to two groups by the percent of body fat(p<0.05). Perceived Stress Scale was no significant correlation with BMI and the percent of body fat. All of the subject were in trouble of high stress. Stress affected dietary restriction owing that perceived stress had a relation with Factor 2(r=0.29, p<0.01) and Factor 3(r=0.37, p<0.01). Also, it affected psychological characteristics owing that perceived stress had a relation with the depression scale, GSI and HDRS(r=0.33, r=0.32, r=0.34, p<0.01). Conclusion: Obese women have more psychological difficulties including depression and high perceived stress, which closely related with the attitude of dietary restriction. Psychiatric intervention and aggressive assessment of psychological problems will be needed to the people who visit the obesity clinic in the future.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.17
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• pp.115-133
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• 1974

This study was done on the metabolism of chemical components during the seed development of ginseng. The changes of the chemical components were inspected in the following periods: from the early stage of flower organ formation to flowering time, from the early stage of fruiting to maturity, during the moisture stratification before sowing. From flower bud forming stage to meiosis stage, the changes in the fresh weight, dry weight, contents of carbohydrates, and contents of nitrogen compounds were slight while the content of TCA soluble phosphorus and especially the content of organic phosphorus increased markedly. From meiosis stage to microspore stage the fresh and dry weights increase greatly. Also, the total nitrogen content increases in this period. Insolub]e nitrogen was 62-70% of the total nitrogen content; the increase of insoluble nitrogen seems to have resulted form the synthesis of protein. The content of soluble sugar (reducing and non-reducing sugar) increases greatly but there was no observable increase in starch content. In this same period, TCA soluble phosphorus reached the maximum level of 85.4% of the total phosphorus. TCA insoluble phosphorus remained at the minimum content level of 14.6%. After the pollen maturation stage and during the flowering period the dry weight increased markedly and insolub]e nitrogen also increased to the level of 67% of the total nitrogen content. Also in this stage, the organic phosphorus content decreased and was found in lesser amounts than inorganic phosphorus. A rapid increase in the starch content was also observed at this stage. In the first three weeks after fruiting the ginseng fruit grows rapidly. Ninety percent of the fresh weight of ripened ginseng seed is obtained in this period. Also, total nitrogen content increased by seven times. As the fruits ripened, insoluble nitrogen increased from 65% of the total nitrogen to 80% while soluble nitrogen decreased from 35% to 20%. By the beginning of the red-ripening period, the total phosphoric acid content increased by eight times and was at its peak. In this same period, TCA soluble phosphorus was 90% of total phosphorus content and organic phosphorus had increased by 29 times. Lipid-phosphorus, nucleic acid-phosphorus and protein-phosphorus also increased during this stage. The rate of increase in carbohydrates was similar to the rate of increase in fresh weight and it was observed at its highest point three weeks after fruiting. Soluble sugar content was also highest at this time; it begins to decrease after the first three weeks. At the red-ripening stage, soluble sugar content increased again slightly, but never reached its previous level. The level of crude starch increased gradually reaching its height, 2.36% of total dry weight, a week before red-ripening, but compared with the content level of other soluble sugars crude starch content was always low. When the seeds ripened completely, more than 80% of the soluble sugar was non-reducing sugar, indicating that sucrose is the main reserve material of carbohydrates in ginseng seeds. Since endosperm of the ripened ginseng seeds contain more than 60% lipids, lipids can be said to be the most abundant reserve material in ginseng seeds; they are more abundant than carbohydrates, protein, or any other component. During the moisture stratification, ginseng seeds absorb quantities of water. Lipids, protein and starch stored in the seeds become soluble by hydrolysis and the contents of sugar, inorganic phosphorus, phospho-lipid, nucleic acid-phosphorus, protein phosphorus, and soluble nitrogen increase. By sowing time, the middle of November, embryo of the seeds grows to 4.2-4.7mm and the water content of the seeds amounts to 50-60% of the total seed weight. Also, by this time, much budding material has been accumulated. On the other hand, dry stored ginseng seeds undergo some changes. The water content of the seeds decreases to 5% and there is an observable change in the carbohydraes but the content of lipid and nitrogen compounds did not change as much as carbohydrates.

• Journal of Nutrition and Health
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• v.50 no.4
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• pp.402-414
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• 2017

Purpose: The purpose of the study was to evaluate the status of safety accidents and importance-performance analysis (IPA) between regular and non-regular employees in industry foodservices. Methods: The participants were regular employees (n = 119) and non-regular employees (n = 163) in industry foodservices in the Jeonbuk area. Demographic characteristics, status of safety accidents, safety education, and importance and performance status were assessed using a self-administered questionnaire. Results: Approximately 66.4% of regular employees and 53.4% of non-regular employees experienced safety accidents (p < 0.05). Types of safety accidents of regular and non-regular employees were mostly burns, and causes were mostly from their own negligence. Approximately 98.3% of regular employees and 95.1% of non-regular employees experienced safety education. Approximately 88.9% of regular employees and 96.8% of non-regular employees received safety education from dietitians. Approximately 41.9% of regular employees and 50.0% of non-regular employees had difficulty applying the contents of safety education due to lack of time during work. As a result of IPA, regular and non-regular employees were aware of the importance of the following and performed them well: 'Clean the floor of the work place', 'Arrange in the work area', 'Wear safety shoes', 'Check for heater cord', and 'Safety cooking when using oil'. On the other hand, they were not aware of the importance of the following and performed them insufficiently: 'Check for the MSDS', 'Aware of chemical signs', 'Wear protection gloves etc.', 'Do stretching exercise', and 'Using ancillary tools'. Conclusion: Therefore, it is necessary to improve the consciousness of dietitians for effective application of safety education contents, development of contents, especially MSDS, and related things.