• Journal of Digital Convergence
• /
• v.17 no.5
• /
• pp.295-301
• /
• 2019

This study examined the effect of insecure attachments, depression, life satisfaction on SNS addiction tendency. Participants were recruited from 3 universities in Seoul, Daejeon and Kyungbook Province. Participants were given the survey including instruments that measured adult attachment, depression, life satisfaction, and SNS addiction tendency. Total 310 participants' data were used for analysis. Multiple regression revealed that SNS addiction tendency was predicted by anxious attachment(${\beta}=.32$, p<.001), depression(${\beta}=.17$, p=.003), and gender(${\beta}=-.25$, p<.001), except life satisfaction, and 26% of the variance was explained by these variables. These findings can help to expand the understanding and the development of the effective prevention/intervention programs of SNS addiction tendency for university students.

• Journal of the Korean Society of Urban Environment
• /
• v.18 no.4
• /
• pp.465-471
• /
• 2018

A field scrutiny related to livestock excretions in Yeongsan stream basin was performed in this study. This result was used to verify the accuracy of nationwide survey result (formal document) for pollution sources by comparing them, and a management plan of livestock excretions was also suggested based on their comparison in this study. The major differences between them were 17.7% in the number of stock farms, 39.6% in the population of milk cows and 41.6% in the treatment method of pig excretions. The biggest difference to the pig case, which is currently the most problem in livestock excretions treatment, could be because of the cause that most of the farmlands, including orchard grove, used as individual treatment site for excretions played role as a dump site to reduce the cost for consignment treatment. Meanwhile, the 67% of compost heaps was illegally left alone in field without the rain shelter and could flow in the stream if it is raining.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.17 no.2
• /
• pp.115-123
• /
• 2007

In cryptographic devices like a smart-card whose computing ability and memory are limited, cryptographic algorithms should be performed efficiently. Scalar multiplication is very important operation in Elliptic Curve Cryptosystems, and so must be constructed in safety against side channel attack(SCA). But several countermeasures proposed against SCA are exposed weaknesses by new un-dreamed analysis. 'Double-and-add always scalar multiplication' algorithm adding dummy operation being known to secure against SPA is exposed weakness by Doubling Attack. But Doubling Attack cannot apply to sABS receding proposed by Hedabou, that is another countermeasure against SPA. Our paper proposes new strengthened Doubling Attacks that can break sABS receding SPA-countermeasure and a detailed method of our attacks through experimental result.

• Fashion & Textile Research Journal
• /
• v.23 no.6
• /
• pp.810-825
• /
• 2021

This study measured and analyzed clothing pressure at each measurement part of commercial body shapers to provide basic information for product design and clothing pressure standard and level. This study used five body shaper. Clothing pressure measurements were taken at 18points: Anterior area 8points, lateral area 5points, posterior area 5points. The findings of this study were as follows. As a result of measuring the clothing pressure, the body shaper 1 showed the highest pressure, and body shaper 5 showed the lowest pressure at almost of the measurement points of the three body types. In some cases, body shapers 2, 3, and 4 showed different orders of pressure depending on the measurement point. The highest measured values in most body shapers were the P1 shoulder area and the P2 bust area. The lowest measurement area differed by body type, but mainly P3 underbust area, P4 thorax area and P9 axillary area, P11 waist lateral area, P13 hip lateral area. These body shapers showed different results depending on the the manufacturers and body type of middle-aged women, and because there was no standard for the pressure value. Therefore, it is necessary to design a body shaper sizing system after accurately setting the clothing pressure value for each body part of the consumer.

• KIPS Transactions on Computer and Communication Systems
• /
• v.10 no.8
• /
• pp.231-234
• /
• 2021

Various problems arise as applications using locations increase. In order to solve this problem, related works are being conducted to protect the location of users. A fundamental reason for this problem is that users must provide their location information to the service provider (server) to receive the service. To improve these problems, there are works such as generating cloaking regions or generating dummies around them. However, if a user periodically asks the server for queries, the user's trajectory may be exposed by time zone. To improve this problem, in this paper, we propose a k-Anonymity Trajectory (k-ATY) technique that can improve the exposure probability of the trajectory even if the user requests continuous queries. Experimental results demonstrated the superiority of the proposed technique.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.4D
• /
• pp.443-450
• /
• 2009

Uninterrupted facility - since there is a close relationship between traffic volume, speed and density -, when a ramp traffic flow merges into the main line, will change the traffic speed or density, and the corresponding correlational model equation will be changed. Thus, this study, using time and space-series traffic data on areas under the influence of such a merging, identified sections which changed the correlation between speed and density variables, and examined such changes. As a result, the upstream and merging sections showed the "Underwood"-shaped exponent, and the downstream after passing the merging section showed a straight line "Greenshields" model. The downstream section which changed the correlation between speed and density showed a gradual downstream movement phenomenon within 100 m-500 m from the end of the third lane linking with the ramp, as the traffic approached the inner lanes. Also, the upstream section, merging section, and downstream section involving a change showed heterogeneous traffic flows which, in the speed-density model, have a statistically different free flow speed (constant) and a different ratio of free flow speed to jam density (gradient).

• The Journal of the Korea Contents Association
• /
• v.22 no.8
• /
• pp.503-517
• /
• 2022

The research results can be summarized in two ways. First, it was confirmed that the provision of public care services for elementary school children had a statistically significant effect on the reduction of children's participation in private education. Second, it was confirmed that the provision of the services had a statistically significant effect on the reduction of children's private education expenses regardless of the mother's economic activity status. Based on this, this study drew the following policy and practical suggestions. First, it is necessary to expand the provision of the services in order to reduce the burden of childrearing of 'working mothers' raising elementary school children. Second, it is necessary to improve quality of the services. To do this, policy-wise, integrated management of services and improvement of treatment of service providers must be made. In the field, it is necessary to improve quality of the services by providing worker education and supervision.

• Explosives and Blasting
• /
• v.42 no.1
• /
• pp.23-33
• /
• 2024

Recently, various techniques and patented methods on blasting operation are being newly developed. In this study, test construction of the MDS blasting method was performed, and the fragmentation size and the occurrence rate of rocks exceeding 300mm were measured and analyzed in comparing to normal blasting method. Test construction was performed three times each for normal and the MDS at the same bench for each round, and fragmentation size(P80) and occurrence rate of rocks exceeding 300mm(S30) were measured using digital image processing. A sieve bucket was also manufactured on-site to sort oversized rock particles from muck piles, and their weights and equivalents were measured to calculate actual values. As a result, the fragmentation size decreased of 21.0% with the MDS compared to normal, and 100-S30 decreased of 10.1%, with actual values decreasing of 7.6%. Although there were variations in blasting effects for each round due to differences in rock quality at site, overall, the MDS proved to be more effective compared to normal blasting method under equivalent conditions.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.9 no.1
• /
• pp.119-132
• /
• 2014

This study analyzed the failure prediction model of the firms listed on the KOSDAQ by considering whether there are embezzlement, malpractice and the largest shareholder changes or not. This study composed a total of 166 firms by using two-paired sampling method. For sample of failed firm, 83 manufacturing firms which delisted on KOSDAQ market for 4 years from 2009 to 2012 are selected. For sample of normal firm, 83 firms (with same item or same business as failed firm) that are listed on KOSDAQ market and perform normal business activities during the same period (from 2009 to 2012) are selected. This study selected 80 financial ratios for 5 years immediately preceding from delisting of sample firm above and conducted T-test to derive 19 of them which emerged for five consecutive years among significant variables and used forward selection to estimate logistic regression model. While the precedent studies only analyzed the data of three years immediately preceding the delisting, this study analyzes data of five years immediately preceding the delisting. This study is distinct from existing previous studies that it researches which significant financial characteristic influences the insolvency from the initial phase of insolvent firm with time lag and it also empirically analyzes the usefulness of data by building a firm's fail prediction model which considered embezzlement/malpractice and the largest shareholder changes as dummy variable(non-financial characteristics). The accuracy of classification of the prediction model with dummy variable appeared 95.2% in year T-1, 88.0% in year T-2, 81.3% in year T-3, 79.5% in year T-4, and 74.7% in year T-5. It increased as year of delisting approaches and showed generally higher the accuracy of classification than the results of existing previous studies. This study expects to reduce the damage of not only the firm but also investors, financial institutions and other stakeholders by finding the firm with high potential to fail in advance.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.18 no.7
• /
• pp.670-676
• /
• 2017

The purpose of this study is to analyze the shipbuilding structure of Hallabong Tangorover ten-day and monthly intervals, to determine whether the shipment control can stabilize and increase the income of Hallabong Tangor farmers by estimating and analyzing the price flexibility function of Hallabong, and to derive the policy implication. Looking at the overall market, the 1% increase in shipment volume indicates that the coefficient of price flexibility varies with time. The largest decline is in late December and early January. The dummy variable indicating the year in which the quality drops somewhat is statistically significant from March to May, and the average of them is -0.337%. This implies a greater importance for quality control and shipment control when quality is worse than good quality. The price flexibility, which indicates price changes due to 1% increase in monthly shipment volume of Hallabong Tangor, varies with time. The coefficient of price flexibility was the highest at -0.46 in December, but prices fell slightly due to quality improvement and the increase in special demand of New Year's demand, which was -0.33% in January, -0.261% in February, -0.307% in March, and -0.318% in April. Since then, the amount of storage has been gradually exhausted, and the price flexibility has fallen slightly to -0.243% in May and -0.236% in June. DUM02, which represents the year when more than 7 days after the New Year holidays are in February is from February to June (+). This indicates that the price decrease due to increase in volume is less than that in January when the New Year is in February. This indicates a greater necessity for shipment control when New Year holidays are in January.