• The Transactions of the Korea Information Processing Society
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• v.6 no.5
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• pp.1280-1290
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• 1999

Applying the change impact analysis to the distributed environment is not straightforward since it is based on the centralized system environment. In this paper, we investigate the change impact analysis of object-oriented shoftwares in the distributed environment. We first, categories the types of changes common in object-oriented software into three sets: data, method, and class level changes. We, then, analyze the impact of each set of changes and represent it in the form of a DPDG. A DPDG is a graph showing relationship of object oriented softwares - with data elements. classes, design documents, servers - in the distributed environment. DPDG searches element of software to retest when the software is changed. Thus, DPDG saves effort of software to retest. In this paper, We propose the table of firewall for retest elements that be discovered by DPDG and implement the table of firewall. The table of firewall is used VIST that we design a software testing tool. The VIST utilizes the minimized firewall, then saves efforts and costs of retesting for distributed object-oriented software.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.10
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• pp.928-935
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• 2010

A bag filter system was partially burnt down during a trial run of waste wood incineration boiler. This brought about unburned hydrocarbon which caused a rapid deactivation of low temperature SCR catalyst set up in two stage after the bag filter. The deactivated catalyst was investigated in order to trace the origin by several characterization methods such as XRD, EDX, BET, TGA, SEM. The deactivated catalyst was regenerated by different methods such as acid washing, water washing in ultrasonication, and calcination treatment under air condition. It is found the calcination treatment under air condition at $450^{\circ}C$ for 2 hours to be the best regeneration method. The catalytic activity was measured in the form of 2 cm ${\times}$ 2 cm ${\times}$ 10 cm (catalyst weight 10 g) honeycomb type. A deNOx efficiency of the regenerated catalyst showed 100% at $180^{\circ}C$ which is the same level of fresh one.

• Journal of Korean society of Dental Hygiene
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• v.13 no.5
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• pp.835-843
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• 2013

Objectives : The purpose of this study was to evaluate the chewing ability, oral-health related quality of life and factors in periodontal disease patients. Methods : Subjects were 111 patients having peridontal disease in 10 dental clinics in Busan and Gyeongsangnamdo. Questionnaire survey was carried out from July to August 2010. Questionnaire consisted of demographic characteristics, oral health factors, chewing ability and quality of life. Data were analyzed by descriptive analysis, t-test, ANOVA, correlation analysis, and multiple regression analysis using SAS(Ver 9.2) set at p<0.05. Results : Chewing ability was $44.85{\pm}8.8$, and their quality of life was $41.7{\pm}8.8$. Low level of quality of life was closely related to those factors as education, missing of more than 5 posterior teeth, certain subjective periodontal symptoms including swollen gums, sore gums, drifting gums, bad breath and toothache. The effective factors to the quality of life was chewing ability, bad breath and toothache. Conclusions : Chewing ability and quality of life were closely related each other. To enhance the quality of life, chewing ability should be improved. Proper treatment and effective method of management should also be properly considered to prevent the subjective periodontal symptoms and to minimize tooth loss.

• Journal of Korean society of Dental Hygiene
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• v.18 no.2
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• pp.165-175
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• 2018

Objectives: This study aims to examine the factors that influence the organizational citizenship behavior of clinical dental hygienists to use them as basic data for improving effectiveness and efficiency of dental clinics and hospitals. Methods: A self-reported questionnaire was answered by 250 clinical dental hygienists in Seoul, Gyeonggi, Chungcheong, Jeolla and Gyeongsang province areas who were chosen using convenient sampling method from May 1st to June 30th of 2017. The data was analyzed using IBM SPSS/WIN 22.0 factor analysis on clinical dental hygienists' organization citizenship behavior, organizational commitment, empowerment, self-leadership and job satisfaction. T-test and one-way ANOVA were performed for subjects' general characteristics and organizational citizenship behavior, organizational commitment, empowerment, self-leadership and job satisfaction depending on their job characteristics. The mean comparison was drawn using the Scheffe test. Pearson's correlation and multiple regression analysis were performed to examine the relation of clinical dental hygienists' organizational citizenship behavior, organizational commitment, empowerment, self-leadership and job satisfaction Also, the significance level was set at 0.05. Results: Clinical dental hygienists' organizational citizenship behavior was 3.84 points with organizational commitment of 3.27, empowerment of 3.41, self-leadership 3.45 and job satisfaction of 3.57. Factors that influence clinical dental hygienists' organizational citizenship behavior appeared in the order of organizational commitment, job satisfaction, self-leadership, empowerment and job intensity, and the model's explanation power was 45.6%. Conclusions: Clinical dental hygienists' organizational citizenship behavior was correlated to career, organizational commitment, empowerment, self-leadership and job satisfaction, where organizational commitment had the biggest influence. Therefore, clinical dental hygienists organizational citizenship behavior needs further studies and investigtae more ways to promote factors that influence organizational citizenship behavior.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.6
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• pp.183-190
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• 2004

This paper proposes a methodology to solve problems upon the circuit design applied to inductor load by applying a circuit to improve power factor with is partial switching PFC module to the power supply system for cooling/heating inverter air conditioner and by designing an input power section in compliance with IEC555-2 on the basis of better input power factor and minimized harmonic components of current. On the other hand, this paper suggested how to control the increase of output voltage along with tぉw current waves and partial switching PFC circuit as well, which can provide the output as twice as input voltage This study applied a method to control the compressors of air conditioner by means of increased the voltage applicable to compressor motor by lowering switching number conclusively, it could solve questions about efficiency, economics, electronic noise and so forth. and so that the reasonable voltage for running moor could be set up along with lower power consumption of air conditioner than estimated It was demonstrated that total sum of energy efficiency to operate system was increased to the extent of valid level. And all this merits and appropriateness was proved by computer simulation and experience.

• Restorative Dentistry and Endodontics
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• v.18 no.1
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• pp.133-143
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• 1993

The aim of this study was to establish reproducible method for measurements of radiopacity and to investigate the level of radiopacity of root canal sealers. The experiments were performed in two parts. In the first part, densitometric readings were performed using an aluminum step wedge as a reference at variable voltages and exposure times. Then standard curves for the aluminum step wedge were compared to comprehend the effect of voltage and exposure time. In the second part, on the basis of these results, appropriate conditions for exposure were adopted for standardized measurements of radiopacity. Under standardized set of conditions, densitometric measurements of ten root canal sealers and one gutta-percha point were performed and the levels of radiopacity referable to an equivalent thickness of aluminum were compared. The following results were obtained : 1. At 50 and 60 kVp, increasing the exposure time caused a decrease in the slope of the standard curve for the aluminum step wedge. However, at 70 kVp increasing the exposure time causing a parallel shift of the standard curve to the right. 2. At constant exposure time, increasing the voltage caused a decrease in the slope of the standard curve. 3. The radiopacity of root canal sealers and a gutta-percha point varied between 2.43 mm Al and 9.20 mm Al equivalent. 4. All the root canal sealers had radiopacities more than dentin, and the radiopacity of the gutta-percha point was approximately 5 times as much as that of dentin in terms of equivalent thickness of aluminum. 5. The AH26 had radiopacity more than the gutta-percha point, and the radiopacities of ZOE, Vitapex, Canals, Kerr PCS, Nogenol were similar to that of the gutta-percha point, and Tubliseal, Apatite II, Apatite III, Silapex were less radiopaque than the gutta-percha point.

• Restorative Dentistry and Endodontics
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• v.42 no.1
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• pp.48-53
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• 2017

Objectives: The aim of this study was to investigate the ability of the fluorescence-aided caries excavation (FACE) device to detect residual caries by comparing conventional methods in vivo. Materials and Methods: A total of 301 females and 202 males with carious teeth participated in this study. The cavity preparations were done by grade 4 (Group 1, 154 teeth), grade 5 (Group 2, 176 teeth), and postgraduate (Group 3, 173 teeth) students. After caries excavation using a handpiece and hand instruments, the presence of residual caries was evaluated by 2 investigators who were previously calibrated for visual-tactile assessment with and without magnifying glasses and trained in the use of a FACE device. The tooth number, cavity type, and presence or absence of residual caries were recorded. The data were analyzed using the Chi-square test, the Fisher's Exact test, or the McNemar test as appropriate. Kappa statistics was used for calibration. In all tests, the level of significance was set at p = 0.05. Results: Almost half of the cavities prepared were Class II (Class I, 20.9%; Class II, 48.9%; Class III, 20.1%; Class IV, 3.4%; Class V, 6.8%). Higher numbers of cavities left with caries were observed in Groups 1 and 2 than in Group 3 for all examination methods. Significant differences were found between visual inspection with or without magnifying glasses and inspection with a FACE device for all groups (p < 0.001). More residual caries were detected through inspection with a FACE device (46.5%) than through either visual inspection (31.8%) or inspection with a magnifying glass (37.6%). Conclusions: Within the limitations of this study, the FACE device may be an effective method for the detection of residual caries.

• Korean Journal of Applied Biomechanics
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• v.28 no.1
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• pp.45-54
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• 2018

Objective: The purpose of this study was to investigate the effect of foot strengthening exercise program and functional insoles on joint angle and plantar pressure in elderly women. Thirteen elderly women who were enrolled in a university senior citizens academy of a metropolitan city in 2017 were divided into two groups: exercise group with functional insole (n=7) and exercise group without functional insole (n=6). Method: Three-dimensional motion analysis and Pedar-X were performed to compute the joint angle and the foot plantar pressure, respectively. Two-way repeated measure ANOVA was conducted to compare dependent variables within and between groups. The significance level was set at ${\alpha}=.05$. Results: The range of motion (ROM) of the ankle, knee, and hip joints in the exercise group with functional insole increased significantly more than the exercise group without functional insole. In both the experimental group and the comparison group, the maximum foot plantar pressure and the mean foot plantar pressure were decreased, but the comparison group without functional insole showed more decrease. Since the experimental group demonstrated greater pressure than the comparison group in the contact area (forefoot, midfoot), it was distributed over a greater area. Conclusion: The results of this study suggest that participation in foot strengthening exercises and using a functional insole has more positive effects than foot strengthening exercises alone on the joint angle and plantar pressure in elderly women. Increased foot plantar pressure led to an increased contact area (forefoot, midfoot) for distribution of the foot plantar pressure, but the effect of reducing the maximum and average plantar pressures was incomplete. However, wearing functional insoles along with exercise, could help in improving the stability of the joints, by increasing the range of motion, and could help the elderly in movement of the muscles more effectively, leading to an improvement in gait function.

• Korean Journal of Applied Biomechanics
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• v.28 no.1
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• pp.29-35
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• 2018

Objective: The purpose of this study was to determine the asymmetry of vertical ground reaction force (GRF) components between dominant and non-dominant legs in rested and fatigued states in prolonged running. Method: Twenty healthy men, heel strikers, were included (age: $24.00{\pm}5.0years$; height: $176.1{\pm}6.0cm$; body mass: $69.0{\pm}6.0kg$) in this study. Subjects ran on an instrumented treadmill for 130 minutes. During treadmill running, GRF data (1,000 Hz) were collected for 20 strides at five minutes (rested) and 125 minutes (fatigued) running while they were unaware of collecting data. Asymmetry indexes (ASI) were calculated to quantify the asymmetry magnitude in rested and fatigued states. Paired t-test was used to verify the differences between dominant and non-dominant legs in rested and fatigued states. In addition, one-way repeated measure analysis of variance was applied for comparison of ASI of both states. The level of significance was set at p < .05. Results: Passive force peak magnitude, loading rate, and impulse affecting the development of running injury were found significantly greater in dominant leg than in non-dominant leg at rested state (p < .05). However, passive force peak time and active force peak magnitude were found significantly different between legs in fatigued state (p < .05). To determine changes in percentage of asymmetry between legs in both states, ASI was used. ASI for all variables increased in fatigued state; however, no significant differences were found between both states. Conclusion: This study found that fatigue did not affect differences in vertical GRF between dominant and non-dominant legs and asymmetry changes.

• Journal of the Korean Society of Physical Medicine
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• v.9 no.2
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• pp.233-242
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• 2014

PURPOSE: The purpose of this study was to determine the correlation between the hip adductor muscles and abdominal muscles during bridge exercise. METHOD: Participants who met the criteria for this study(n=36) were divided into the three groups. The first experimental group performed normal bridge exercises and the second group performed bridge exercises with the contraction of the hip adductor muscles and the control group didn't perform any exercise. Transversus abdominis muscle thickness was measured by ultrasound imaging with a special transducer head device, at pre exercise, after 2 weeks, 4 weeks, and 6 weeks. RESULT: Data were analyzed using repeated ANOVA with the level of significance set at ${\alpha}=.05$. Transversus abdominis muscle thickness was influenced by contraction of the hip adductor muscles during bridge exercise in people without lower back pain. Compared with normal bridge exercise, transversus abdominis muscle thickness significantly increased in thickness during bridge exercise with contraction of the hip adductor muscles(p<.05). CONCLUSION: The results from this study showed that contraction of the hip adductor muscles during bridge exercise increased change in the transversus abdominis muscle thickness. These results can be a good source to prevent low back pain due to hip adductor weakness. Therefore, inducing activation of hip adductor with abdominal stabilizing exercise is more effective in patients with low back pain.