• Journal of Periodontal and Implant Science
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• v.24 no.3
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• pp.581-596
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• 1994

This in vitro study was undertaken to obtain optimal tetracycline concentration that aids proliferation and spreading of human periodontal ligament cells, for clinical application in root surfaces of periodontally diseased teeth. Periodontal ligament cells used in this study were obtained from explants of periodontal ligament of 1st premolar teeth which were extracted for the purpose of orthodontic treatment. The cells were cultured in Dulbecco's Modified Eagle Medium(DMEM) supplemented with 100 U/ml penicillin, $100\;{\mu}g/ml$ streptomycin and 10% FBS at $37^{\circ}C$, 100% humidity, 5% $CO_2-95%$ air. Cells were used between the third to 4th passage. After root planing of periodontally extracted teeth, the root slabs were cut with carborundum disk. In the cell proliferation experiment, experimental groups were root planing only group, immersed groups in 25, 50, 75, 100, 150mg/ml aqueous solution of Tetracycline HCl followed by a vigorous rinse in PBS. Human PDL cells at concentration of $1{\times}10^5\;cells/ml$ were seeded in each culture well which contained root slabs and incubated for 6 hours. Then, all of the root slabs were moved into new 24 culture well and incubated 24, 48 and 72 hours. The cell counting was done by inverted phase contrast microscope after trypsinization. The following results were obtained. The cell number was increased in order root planing only group, 25, 150, 50, 75, 100mg/ml of Tetracycline HCl treated group in 24, 48 and 72 hours. The maximal cell number was obtained when the root slabs were immersed in solution with 100mg/ml of Tetracycline HCl. There were statistically significant between the root planing only group and 75, 100 mg/ml of Tetracycline HCl treated group in 24 hours, between the root planing only group and 100mg/ml of Tetracycline HCl treated group in 48 hours, between the root planing only group and 50, 75, 100mg/ml of Tetracycline HCl treated group, between 25 and 100mg/ml of Tetracycline HCl treated group in 72 hours(p<0.05). In the cell spreading experiment, after 30 minutes of incubated, in the root planing only group, the cells were generally round in shape. The cell surface was mostly covered with blebs. The cells started to attach to root surface by cytoplasmic extension in 50, 100mg/ml of Tetracycline HCl treated groups, more numerous cells attached to root surface than root planing only group. Many orifices of dentinal tubule were exposed, cells showed radially spreaded cytoplasm and unspreaded central region of the cell was covered with blebs. After 6 hours of incubation, in the root planing only group, cells showed radially spreaded cytoplasm and were attached flat appearance. In 50, 100mg/ml of Tetracycline HCl treated groups, cellular margin was concaved and cytoplasm showed elongated appearance with polarity. After 24 hours of incubation, in the root planing group, cells showed characteristic polarity. In 50, 100mg/ml of Tetracycline HCl treated groups, cells showed more elongated and spindle - like appearance.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1594-1606
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• 2014

The purpose of this study was to examine safety accidents related to school foodservice, working and operating environments of school foodservice, status and awareness of safety education, educational needs, and information on qualitative improvement of school foodservice. The subjects in this study were 234 cooks in charge of cooking at elementary and secondary schools in Chungbuk. A survey was conducted from July 30 to August 8, 2012, and among 202 questionnaires gathered, 194 completed questionnaires were analyzed. Statistical analyses were performed on data utilizing the SPSS version 19.0. The main results of this study were as follows: 44.3% of workers experienced safety accidents. The most frequent safety accident was 'once' (60.5%), and most safety accidents took place between June and August (31.4%). The time at which most safety accidents happened was between 8 and 11 am. Most safety accidents happened during cooking (52.3%) and while using a soup pot or frying pot (52.4%). The most common accidents were 'burns', 'wrist and arm pain', and 'slips and falls'. Respondents who experienced safety accidents replied that 57.6% of employees dealt with injuries at their own expense, and only 35.3% utilized industrial accident insurance. In terms of the operating environment, the score for 'offering information and application' was highest (3.76 points), whereas that for 'security of budget' was lowest (1.77 points). As for accident education, employees received safety education approximately 3.45 times and 5.10 hours per year. Improving the working environment of school foodservice cooks requires administrative and financial support. Furthermore, educational materials and guidelines based on the working environment and safety accident status of school foodservice cooks are required in order to minimize potential risk factors and control safety accidents in school foodservice.

• Journal of Gastric Cancer
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• v.5 no.2
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• pp.89-94
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• 2005

Purpose: Early gastric cancer (EGC) has an excellent prognosis compared to advanced gastric cancer. The 5-year survival rate for EGC now exceeds $90\%$, and EGC is recognized as a curable malignancy. The important prognostic factor in EGC is the status of lymph-node metastasis. Despite conserving surgery being suggested for EGC at present, it is of vital importance to select a surgical method appropriate to each individual case. This retrospective study was undertaken to clarify clinicopathologic features and factors related to lymph-node metastasis in submucosal gastric cancer in order to determine an appropriate therapy. Materials and Methods: This study analyzed the clinicopathologic features for 279 patients with a submucosal gastric carcinoma (Group I) and compared with those of patients with mucosal (Group II) or muscularis proprial gastric carcinoma (Group III). All patients were operated on from 1981 to 1999 at Chonnam University Hospital. There were no statistically significant differences among the groups with respect to age, gender, tumor location, hepatic metastasis, or peritoneal dissemination. Results: Positive lymph node metastasis was found in 47 ($16.8\%$) of the 279 patients with a submucosal gastric carcinoma. The incidence of lymph-node metastasis was significantly higher in patients with a submucosal gastric carcinoma than in patients with a mucosal gastric carcinoma ($16.8\%\;vs.\;3.9\%\;$; P<0.01). Therefore, depth of invasion was a significant factor affecting in lymph-node metastasis. The 5-year survival rates were $88.6\%$ for patients in Group I, $95.2\%$ for patients in Group II, and $72.7\%$ for patients in Group III (P<0.01 for Group I vs. Group II; Group I vs. Group III). In patients with a submucosal gastric carcinoma, the survival rate with positive lymph nodes was significantly poorer than that of patients without lymph-node metastasis ($87.3\%\;vs.\;94.2\%$; P<0.01). Conclusion: Gastrectomy with D2 lymph node dissection is an appropriate operative procedure for patients with a submucosal gastric carcinoma.

• Tuberculosis and Respiratory Diseases
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• v.49 no.1
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• pp.37-48
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• 2000

Backgrounds : The pathophysiology of chronic airflow obstruction, such as bronchial asthma, is characterized by mucus hypersecretion, goblet cell hyperplasia(GCH), smooth muscle hypertrophy, and inflammatory cells infiltration. In fatal asthma patients, one distinct findings is mucus hypersecretion due to GCH. However, the mechanisms of GCH in these hypersecretory diseases remain still unknown. In this study, a rat model was rapidly induced with GCH by instillation of $TiO_2$, intratracheally. We intend to confirm GCH and association of concomitant inflammatory cells infiltration and to observe the effect of potent antiinflammatory agent, that is dexamethasone, on GCH with inflammatory cells. Methods : Twenty-one 8-weeks-old male Sprague-Dawley rats were divided into three groups. Endotoxinfree water was instilled intratracheally in group 1(control) ; $TiO_2$, was instilled in the group 2 ; and dexamethasone was injected intraperitoneally to group 3 before $TiO_2$ instillation. After 120 hours, all rats were sacrificed, and trachea, bronchi, and lungs were resected respectively. These tissues were made as paraffin blocks and stained as PAS for goblet cells and Luna stain for eosinophils. We calculated the ratio of goblet cell to respiratory epithelium and number of infiltrated eosinophils from each tissue. Results : (1) Fraction of goblet cells was significantly increased in group 2 than in group 1 in the trachea and in the main bronchus. (10.19$\pm$11.33% vs 4.09$\pm$8.28%, p<0.01 and 34.09$\pm$23.91% vs 3.61$\pm$4.84%, p<0.01, respectively). (2) Eosinophils were significantly increased in the airway of group 2 than that of group 1. (5.43$\pm$3.84% vs 0.17$\pm$0.47 in trachea and 47.71$\pm$16.91 vs 2.71$\pm$1.96 in main bronchi). (3) There was a positive correlation between goblet cells and eosinophils(r=0.719, p=0.001). (4) There was significant difference in the decrease of goblet cells after dexamethasone injection between group 2 and group 3 (p<0.01). Also, infiltration of eosinophils was suppressed by dexamethasone. Conclusion : We made an animal model of $TiO_2$-induced goblet cell hyperplasia. GCH was observed mainly in the main bronchi with concomitant eosinophilic infiltration. Both goblet cell hyperplasia and eosinophilic infiltration were suppressed by dexamethasone. This animal model may serve as a useful tool in understanding of the mechanism of GCH in chronic airway diseases.

• Tuberculosis and Respiratory Diseases
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• v.41 no.5
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• pp.521-530
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• 1994

Background : The past studies on prediction formulas of pulmonary function parameters in healthy nonsmoking Korean adults have been performed in relatively small number of subjects and the reported results were restricted on a few parameters. Also there was no systematic investigation into the effect of smoking on pulmonary function parameters in smokers who have no respiratory symptoms. Therefore we attempted to establish prediction formulas of pulmonary function parameters and examined the effect of smoking on pulmonary function parameters. Methods We analyzed the result of parameters derived from the forced expiratory spirogram in 1,067 nonsmoking subjects from June in 1990 to December in 1991. They consisted of 306 males and 761 females and had neither respitatory symptoms nor history of respiratory disease. We derived prediction formulas by multiple linear regression method from their age, heights, and weights in each sex. To examine the effect of smoking on pulmonary function parameters, we classified 383 smoking men into three groups according to the past amount of smoking as follows : i.e. group of smokers who have smoked below 10 pack-years, 10-20 pack-years and above 20 pack-years. Regarding each group of past smoking as an independent dummy variable, we analyzed pulmonary function parameters including nonsmoking men as a baseline by multiple linear regression. We evaluated the smoking effect on pulmonary function parameters according to estimated p-value. Result : 1) Prediction formulas for pulmonary function parameters in each sex were derived. 2) The past smoking less than 10 pack-years does not give any effect on pulmonary function parameters. The past smoking of 10~20 pack-years showed significant negative correlation with $FEV_1$/FVC and FEF 25~75%, and the smoking above 20 pack years showed negative correlation with $FEV_1$ and $FEV_1$/FVC. Conclusion : We have got prediction formulas of pulmonary function parameters which is driven from forced expiratory spirogram in nonsmoking Korean adults by multiple linear regression from age, heights and weights of subjects. The past smoking more than 10 pack-years showed negative correlation with some pulmonary function parameters of airflow obstruction.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.766-772
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• 2000

Background : Pressure rise time (PRT) is the time in which the ventilator aclieves the set airway pressure in pressure-targeted modes, such as pressure control ventilation (PCV). With varying PRT, in principle, the peak inspiratory flow rate of the ventilator also varies. And if PRT is set to a shorter duration, the effective duration of target pressure level would be prolonged, which in turn would increase inspiratory tidal volume(Vti) and mean airway pressure (Pmean). We also postulated that the increase in Vti with shortening of PRT may relate inversely to the patients' basal airway resistance. Methods : In 13 paralyzed patients on PCV (pressure control 18$\pm$9.5 cm $H_2O$ $FIO_2\;0.6\pm0.3$, PEEP 5$\pm$3 cm $H_2O$, f 20/min, I : E1 : 2) with Servo 300 (Siemens-Elema, Solna, Sweden) from various causes of respiratory failure, PRT of 10 %, 5 % and 0 % were randomly applied. At 30 min of each PRT trial, peak inspiratory flow (PIF, L/sec), Vti (ml), Pmean (cm $H_2O$) and ABGA were determined. Results : At PRT 10%, 5%, and 0%, PIF were 0.69$\pm$0.13, 0.77$\pm$0.19, 0.83$\pm$0.22, respectively (p<0.001). Vti were 425$\pm$94, 439$\pm$101, 456$\pm$106, respectively (p<0.001), and Pmean were 11.2$\pm$3.7, 12.0$\pm$3.7, 12.5$\pm$3.8, respectively (p<0.001). pH were 7.40$\pm$0.08, 7.40$\pm$0.92, 7.41$\pm$0.96, respectively (p=0.00) ; $PaCO_2$ (mm Hg) were 47.4$\pm$15.8, 47.2 $\pm$15.7, 44.6$\pm$16.2, respectively (p=0.004) ; $PAO_2-PaO_2$ (mm Hg) were 220$\pm$98, 224$\pm$95, 227$\pm$94, respectively (p=0.004) ; and $V_n/V_T$ as determined by ($PaCO_2-P_E-CO_2$)/$PaCO_2$ were 0.67$\pm$0.07, 0.67$\pm$0.08, 0.66$\pm$0.08, respectively (p=0.007). The correlation between airway resistance and change of Vti from PRT 10% to 0% were r= -0.243 (p=0.498). Conclusion : Shortening of pressure rise timee during PCV was associated with increased tidal volume, increased mean airway pressure and lower $PaCO_2$.

• Tuberculosis and Respiratory Diseases
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• v.60 no.4
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• pp.451-463
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• 2006

Background : Reactive oxygen species (ROS) take center stage as executers in ventilator-induced lung injury (VILI). The protein with DNA-damage scanning activity, poly (ADP-ribose) polymerase-1 (PARP1), signals DNA rupture and participates in base-excision repair. Paradoxically,overactivation of PARP1 in response to massive genotoxic injury such as ROS can induce cell death through ${\beta}$ -nicotinamide adenine dinucleotide ($NAD^+$) depletion, resulting in inflammation. The purpose of this study is to investigate the role of PARP1 and the effect of its inhibitor in VILI. Methods : Forty-eight male C57BL/6 mice were divided into sham, lung protective ventilation(LPV), VILI, and PARP1 inhibitor (PJ34)+VILI (PJ34+VILI) groups. Mechanical ventilator setting for the LPV group was $PIP\;15cmH_2O$ + $PEEP\;3cmH_2O$ + RR 90/min + 2 hours. The VILI and PJ34+VILI groups were ventilated on a setting of $PIP\;40cmH_2O$ + $PEEP\;0cmH_2O$ + RR 90/min + 2 hours. As a PARP1 inhibitor for the PJ34+VILI group, 20 mg/Kg of PJ34 was treated intraperitoneally 2 hours before mechanical ventilation. Wet-to-dry weight ratio and acute lung injury (ALI) score were measured to determine the degree of VILI. PARP1 activity was evaluated by using an immunohistochemical method utilizing biotinylated NAD. Myeloperoxidase (MPO) activity and the concentration of inflammatory cytokines such as tumor necrosis factor $(TNF)-{\alpha}$, interleukin $(IL)-1{\beta}$, and IL-6 were measured in bronchoalveolar lavage fluid (BALF). Results : In the PJ34+VILI group, PJ34 pretreatment significantly reduced the degree of lung injury, compared with the VILI group (p<0.05). The number of cells expressing PARP1 activity was significantly increased in the VILI group, but significantly decreased in the PJ34+VILI group (p=0.001). In BALF, MPO activity, $TNF-{\alpha}$, $IL-1{\beta}$, and IL-6 were also significantly lower in the PJ34+VILI group (all, p<0.05). Conclusion : PARP1 overactivation plays a major role in the mechanism of VILI. PARP1 inhibitor prevents VILI, and decreases MPO activity and inflammatory cytokines.

• 한국벤처창업학회:학술대회논문집
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• 2009.10a
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• pp.265-288
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• 2009

The study has found that the main reasons affecting to the mature conjugal relations of middle-aged persons are closely related with sede factors brought about after marriage. Comparatively the factors before marriage have more or less weak power on the conjugal relations. They are mature relations wp between husbands and wives, stable and enough incede, and religious activities, which have deep relations with the satisfactory conjugal relations. C. G. Jung divided the whole life span as self-assuredness period in the first half and self-convergence period in the second half. The first is the period when one does his or her best to get external and physical self. On the contrary, the second is the middle-aged period one finds his or her meaning of life in the religious, philosophical, intuitional, and spiritual world, which lead life into harmony and integration. Therefore if one overcomes some psychological crisis related with middle-aged development he or she can enjoy happy senescence(old age). The study has suggested through literature investigation the definition of middle age and the developmental traits of middle age, and the relations between religions and conjugal relations of middle-aged husbands and wives. Futhermore, it has analyzed the theories which religions have close relations with the life satisfaction of middle-aged conjugal relations. In order to give an analysis the influence of the variable of religious activities and religious maturity, with the degree of conjugal satisfaction, 400 middle age are selected as the object of the study whose ages are ranging from 35 years to 60 years, and who reside in Seoul or near Seoul. They were asked to fill out the questionnaires asking about religious activities, religious maturity, and the conjugal satisfaction from March 25th to April 30th, 2009. The results of the survey have been statistically processed and analyzed. First, the higher religious maturity gives positive influence on the general religious activities including public service, human relations, and spiritual stability. That is, this result indicates that the individual, spiritual, and formal religious activities give to a degree influence on the religious maturity. Second, the maturity of religious life resulting from religious activities has a causation with the satisfaction of conjugal life. In more details, religious activities has a positive influence on the satisfaction of conjugal life(T=31.36, p<.001) In more details, religious activities has a positive influence on the religious maturity(T=31.36, p<.001), and religious activities has a positive influence on the satisfaction of conjugal life(T=33.81, p<.001), and the religious maturity has a positive influence on the satisfaction of conjugal life(T=28.64, p<.001) Third, as we analyze the main effects which religious activities and the religious maturity could give influence on the satisfaction of conjugal life, it is found that both religious activities(F=15.95, p<.001) and the religious maturity(F=23.94, p<.001) give a positive influence on the satisfaction of conjugal life. In conclusion, it is sure that religious activities and the religious maturity have a close relations with the satisfaction of conjugal life. Therefore it can be said that religious activities at the protestant religion, buddhism, and catholic religion can give an important influence on the satisfaction of middle-aged conjugal life.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.285-301
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• 2020

Looking at the problem of aging in the nation from a demographic perspective, it is not a problem of the overall population, but of the structure of the population. It is the baby boomer and post-baby boomers, the largest population in the country. Baby boomers were born between 1955 and 1963, and currently have a population of 7001,333, which is 13.6 percent (as of 2015). The Post-Baby Boomer generation was born between 1964 and 1974, with a total population of 9,567,171, accounting for 18.8 percent of the total population. In particular, baby boomers and post-baby boomers (32.4% of the total population) have begun to retire or will retire soon. The average life expectancy continues to increase due to the development of medical technology, and the falling birth rate of newborns and the declining population of the production population are darkening the domestic economy. In a policy proposal aimed at easing the nation's falling economic growth rate, women's participation rate is as high as Sweden and men's efforts to increase it as high as Japan's, while the elderly rate is desirable to maintain Korea's high level. This is because the expansion of the elderly generation's participation in economic activities could ease a sharp drop in economic growth and reduce the burden of supporting the elderly population. The study, based on this social problem awareness and problem solving plan, looks at the relationship between career orientation and satisfaction in start-up education based on the diverse career base of active seniors, and also suggests the importance of customized start-up education on the diversity of active seniors by clarifying the relationship between them, and suggests the desirable direction of senior start-up policy design, funding, and start-up education. Based on the theoretical background, the concept of five factors was defined: active senior, career-oriented, satisfaction level of start-up education, willingness to start a business, and the concept definition of an active senior, which is particularly key to the baby boomers in their 50s and 60s, is generally regarded as a source of consumption or welfare benefits, but in this study, the concept of active start-up is reflected in the domestic start-up market by young people in their 40s, 50s and 60s. As a result of a hypothesis test. Hypothesis 1 and Hypothesis 5: Career orientation has been verified to affect the willingness to start a business and the behavior of preparation for a start-up. Hypothesis 3: The willingness to start a business has been verified as having an effect between startup preparation actions. Hypothesis 4: The satisfaction level of start-up education has been verified to affect start-up preparation behavior. However, hypothesis 2: The satisfaction level of education for start-ups does not affect the willingness to start a business. Such results can be inferred that satisfaction in start-up education does not have a direct effect on the will to start a business and increases the will to start a business through the influence of personal career orientation.

• Information Systems Review
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• v.14 no.3
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• pp.75-97
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• 2012

Fostering trusting belief in financial transactions is a challenging task in Internet banking services. Authenticated Certificate had been regarded as an effective method to guarantee the trusting belief for online transactions. However, previous research claimed that this method has some loopholes for such abusers as hackers, who intend to attack the financial accounts of innocent transactors in Internet. Two types of methods have been suggested as alternatives for securing user identification and activity in online financial services. Control transparency uses information over the transaction process to verify and to control the transactions. Outcome feedback, which refers to the specific information about exchange outcomes, provides information over final transaction results. By using these two methods, financial service providers can send signals to involved parties about the robustness of their security mechanisms. These two methods-control transparency and outcome feedback-have been widely used in the IS field to enhance the quality of IS services. In this research, we intend to verify that these two methods can also be used to reduce risks and to increase the security protections in online banking services. The purpose of this paper is to empirically test the effects of the control transparency and the outcome feedback on the risk perceptions in Internet banking services. Our assumption is that these two methods-control transparency and outcome feedback-can reduce perceived risks involved with online financial transactions, while increasing perceived trust over financial service providers. These changes in user attitudes can increase the level of user satisfactions, which may lead to the increased user loyalty as well as users' willingness to pay for the financial transactions. Previous research in IS suggested that the increased level of transparency on the process and the result of transactions can enhance the information quality and decision quality of IS users. Transparency helps IS users to acquire the information needed to control the transaction counterpart and thus to complete transaction successfully. It is also argued that transparency can reduce the perceived transaction risks in IS usage. Many IS researchers also argued that the trust can be generated by the institutional mechanisms. Trusting belief refers to the truster's belief for the trustee to have attributes for being beneficial to the truster. Institution-based trust plays an important role to enhance the probability of achieving a successful outcome. When a transactor regards the conditions crucial for the transaction success, he or she considers the condition providers as trustful, and thus eventually trust the others involved with such condition providers. In this process, transparency helps the transactor complete the transaction successfully. Through the investigation of these studies, we expect that the control transparency and outcome feedback can reduce the risk perception on transaction and enhance the trust with the service provider. Based on a theoretical framework of transparency and institution-based trust, we propose and test a research model by evaluating research hypotheses. We have conducted a laboratory experiment in order to validate our research model. Since the transparency artifact(control transparency and outcome feedback) is not yet adopted in online banking services, the general survey method could not be employed to verify our research model. We collected data from 138 experiment subjects who had experiences with online banking services. PLS is used to analyze the experiment data. The measurement model confirms that our data set has appropriate convergent and discriminant validity. The results of testing the structural model indicate that control transparency significantly enhances the trust and significantly reduces the risk perception of online banking users. The result also suggested that the outcome feedback significantly enhances the trust of users. We have found that the reduced risk and the increased trust level significantly improve the level of service satisfaction. The increased satisfaction finally leads to the increased loyalty and willingness to pay for the financial services.