• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.23 no.4
• /
• pp.743-755
• /
• 2013

In recent years, the malicious apps with malicious code in normal apps are increasingly redistributed in Android market, which may incur various problems such as the leakage of authentication information and transaction information and fraudulent transactions when banking apps to process the financial transactions are exposed to such attacks. Thus the financial authorities established the laws and regulations as an countermeasures against those problems and domestic banks provide the integrity verification functions in their banking apps, yet its reliability has not been verified because the studies of the safety of the corresponding functions have seldom been conducted. Thus this study suggests the vulnerabilities of the integrity verification functions of banking apps by using Android reverse engineering analysis techniques. In case the suggested vulnerabilities are exploited, the integrity verification functions of banking apps are likely to be bypassed, which will facilitate malicious code inserting attacks through repackaging and its risk is very high as proved in a test of this study. Furthermore this study suggests the specific solutions to those vulnerabilities, which will contribute to improving the security level of smartphone financial transaction environment against the application forgery attacks.

• Journal of Navigation and Port Research
• /
• v.31 no.8
• /
• pp.629-635
• /
• 2007

Reduced crew performance is frequently cited as a major causal factor in maritime accident causation. Although considerable research has been conducted on the hours of work undertaken by seafarers through interviews and the analysis of records, experimental studies to observe the effects of factors such as high workload, shift patterns, stress, sleep deprivation and disturbance on the cognitive performance of mariners have been limited. Other safety-critical transport industries, such as aviation and rail, have developed fatigue management tools to help manage the work patterns of their operators. Such a tool for mariners would assist shipboard crew, marine pilots and shore management in planning and improving work schedules. The overall aim of this paper is to determine a fatigue factor, which can be applied to human performance data, as part of a software program that calculates total cognitive performance. This program enables us to establish the levels of cognitive performance of a group of marine pilots to test a decision-making task based on radar information. This paper addresses one of the factors that may contribute to the determination of various fatigue factors: the effect of different work patterns on the cognitive performance of a marine pilot.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.40 no.2
• /
• pp.175-183
• /
• 2016

The endurance reliability assessment of a highly complex mechanism is generally predicted by the fatigue life based on simple stress analysis. This study discusses various fatigue life assessment techniques for an automobile clutch snap ring. Finite element analyses were conducted to determine the structural stress on the snap ring. Structural stress that is insensitive in regards to the mesh size and type definition is presented in this study. The structural stress definition is consistent with elementary structural mechanics theory and provides an effective measure of a stress state that pertains to fatigue behavior of welded joints in the form of both membrane and bending components. Numerical procedures for both solid models and shell or plate element models are presented to demonstrate the mesh-size insensitivity when extracting the structural stress parameters. Conventional finite element models can be used with the structural stress calculations as a post-processing procedure. The two major implications from this research were: (a) structural stresses pertaining to fatigue behavior can be consistently calculated in a mesh-insensitive manner regardless of the types of finite element models; and (b) by comparing with the clutch snap-ring fatigue test data, we should predict the fatigue fractures of an automobile clutch snap ring using this method.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.10
• /
• pp.1093-1100
• /
• 2014

The purpose of this paper is to suggest a weight-reduction design method for the hybrid carbody of a high-speed maglev train that uses aluminum extrusion profiles and sandwich composites. A sandwich composite was used on the roof as a secondary member to minimize the weight. In order to assemble the sandwich composite roof and aluminum extrusion side frame of the carbody using welding, a guide aluminum frame located at the four sides of the sandwich composite roof was introduced in this study. The clamping force of this guide aluminum frame was verified by three-point bending test. The structural integrity and crashworthiness of the hybrid carbody of a high-speed maglev train were evaluated and verified according to the Korean Railway Safety Law using a commercial finite element analysis program. The results showed that the hybrid carbody composed of aluminum extrusion frames and a sandwich composite roof was lighter in weight than a carbody made only of aluminum extrusion profiles and had better structural performance.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.9
• /
• pp.959-965
• /
• 2014

In the present study, we aimed to obtain design data that can be used for the side members of lightweight cars by experimentally examining the types of effects that the changes in the section shape and outermost layer of an aluminum (Al)/carbon fiber reinforced plastic (CFRP) composite structural member have on its collapse characteristics. We have drawn the following conclusions based on the test results: The circular Al/CFRP composite impact-absorbing member in which the outermost layer angle was laminated at $0^{\circ}$ was observed to be 52.9 and 49.93 higher than that of the square and hat-shaped members, respectively. In addition, the energy absorption characteristic of the circular Al/CFRP composite impact-absorbing member in which the outermost layer angle was laminated at $90^{\circ}$ was observed to be 50.49 and 49.2 higher than that of the square and hat-shaped members, respectively.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.11 no.1
• /
• pp.56-69
• /
• 2001

Objectives : This study was designed to develop and standardize a checklist for ergonomic risk factors, and to provide ergonomic guidelines for managing cumulative trauma disorders (CTDs) in automobile assembly lines. Methods : The Checklist for Ergonomic Risk Factors (CERF-1) was developed based on the results of previous studies, and then modified after performing pilot study. Information on the symptoms possibly related with CTDs was obtained using a self-reported Questionnaire from 465 automobile assembly workers. Their job conditions were examined to assess risk factors through both direct observation and video analysis. Results : Rate of detecting risky job through CERF-1 was 85.6%, and was similar to that (88.8%) by Occupational Safety and Health Adminstration(OSHA) checklist but higher than that (63.7%) by American National Standards Institute(ANSI) Z-365. Relationship of the exposure scores derived from CERF-1 with levels of symptom was greater (r=0.49) than OSHA (r=0.28) and ANSI Z-365 (r=0.22). Considering the relationship, jobs scoring higher than 16 could be classified as the Risk Job. and lower than 16 as the Low Risk Job. Sensitivity and specificity of the Risk Job were 92.5 % and 31.5 %, respectively. Odds ratio (OR) after age adjustment was 5.69 (95 % confidence interval 3.15-10.29) for the Risk Job, and these ORs were significantly different from those of the Low Risk Job. The exposure scores were Quite valid, in that the scores at the main survey were significantly correlated with those at the follow-up survey, as suggested by test-retest(r=0.88) and inter-rater reliability(r=0.80). Conclusions : The CERF-1, developed in this study, will be an efficient tool for evaluation of risk jobs for CTDs in automobile assembly lines, and can be used easily by health care providers.

• Journal of the Korean Society of Radiology
• /
• v.13 no.7
• /
• pp.901-907
• /
• 2019

The aim of this study is to evaluate the ability of target localizations of Leksell GammaPlan(LGP) in Gamma Knife Subthalamotomy(or Pallidotomy, Thalamotomy) of functional diseases. To evaluate the accuracy of LGP's location settings, the difference Δr of the target coordinates calculated by LGP (or LSP) and author's algorithm was reviewed for 10 patients who underwent Deep Brain Stimulation(DBS) surgery. Δr ranged from 0.0244663 mm to 0.107961 mm. The average of Δr was 0.054398 mm. Transformation matrix between stereotactic space and brain atlas space was calculated using PseudoInverse or Singular Value Decomposition of Mathematica to determine the positional relationship between two coordinate systems. Despite the precise frame positioning, the misalignment of yaw from -3.44739 degree to 1.82243 degree, pitch from -4.57212 degree to 0.692063 degree, and rolls from -6.38239 degree to 7.21426 degree appeared. In conclusion, a simple in-house algorithm was used to test the accuracy for location settings of LGP(or LSP) in Gamma Knife platform and the possibility for Gamma Knife Subthalamotomy. The functional diseases can be treated with Gamma Knife Radiosurgery with safety and efficacy. In the future, the proposed algorithm for target localizations' QA will be a great contributor to movement disorders' treatment of several Gamma Knife Centers.

• Journal of Sericultural and Entomological Science
• /
• v.50 no.1
• /
• pp.20-26
• /
• 2012

In this study, silk gland powder of silkworm were investigated to see the possibility for baby powder cosmetics materials. To test possibility as a baby powder cosmetics, total content rate of amino acids, DPPH free radical scavenging assay, MTT assay, and clinical trial were done. According to the result of the analysis of the amino acids of silk gland powder, serin (26.77%) content was the highest and asparatic acid (15.47%), and glycine (9.62%) were followed. DPPH free radical scavenging activity of silk gland powder was lower than vitamin C by 82.3% and 97%, respectively, which is relatively good. Moisture effect were increased in silk gland powder compared to control cosmetics by 50%. Also, silk gland powder was classified as a practically non-irritating material based on the score 0.05 of primary irritation index. Thus, these results suggest that silk gland powder of silkworm may have beneficial properties as a material for baby powder cosmetics.

• Journal of Korean Society of Transportation
• /
• v.27 no.2
• /
• pp.35-46
• /
• 2009

This paper presents an evaluation index for the supply levels of pedestrian facilities in residential area planning. The pedestrian facility supply levels reveal the quality of a residential area, and can be associated with the resident living standards and satisfaction, pedestrian safety levels, and the effectiveness of the construction cost. This research conducted multifaceted procedures for the index development, and these procedures start first by identifying dominant influencing factors on pedestrian travel demand by reviewing the final reports of site planning in more than eight already-completed residential development sites. Second, based on the Space Syntax model, which was initially developed in the UK by establishing statistical relationships among an integration index, population size (persons/day), and the total development area, this research formulated a set of pedestrian demand estimation models. Then these models were utilized in forming a pedestrian facility supply index by integrating the new models and their results with the available accepted practice in the residential planning sector. This was necessary because planners want to understand the total supply level of pedestrian facilities in a residential area during the initial design stage. Finally, to test the model validity in satisfying pedestrian satisfaction, the research included a resident satisfaction interview, and it was revealed that the evaluation index developed in this research could provide planners and engineers with more promising results. It is therefore anticipated that this research can be of service when designing pedestrian facilities in future residential area planning and design activities.

• Journal of Korean society of Dental Hygiene
• /
• v.12 no.5
• /
• pp.871-879
• /
• 2012

Objectives : The purpose of this study was to investigate the factors related to the awareness level of community water fluoridation program. Methods : 700 subjects were surveyed among the residents living in Incheon Metropolitan City. Data were collected on awareness of community water fluoridation program, general factors, oral health behavior, self-reported oral health and oral health interest. The factors related to the awareness level of community water fluoridation program were analyzed by t-test, a one way ANOVA and multiple linear regression analysis. Results : 1. Subjects' ages were 40~59 years, monthly average incomes were more than 3 million won and higher their educational levels had a higher awareness level of community water fluoridation program(p<0.01). 2. People who brushed their teeth more than three times a day, used oral hygiene devices, and had periodic oral examination and removed plaques were had higher awareness level of community water fluoridation program(p<0.01). Especially, the use of oral hygiene devices was the strongest factor in relation with the awareness level of community water fluoridation program(p<0.01). 3. People who had a fine self-reported oral health, highly interested in dental hygiene and made an effort to keep oral health were had higher awareness level of community water fluoridation program(p<0.001). Conclusions : The awareness level of community water fluoridation program was related to oral health behavior, self-reported oral health and oral health interest. So, in order to expand the areas for community water fluoridation program, it is important to educate to the right information about objectives, safety, dental caries preventing effect of the community water fluoridation program. And the education and publicity on general oral health will have an affirmative effect on expanding community water fluoridation program.