• Journal of dental hygiene science
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• v.15 no.4
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• pp.509-517
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• 2015

This study attempted to identify the entrance exam stress levels in high school students and analyze the relationship this entrance exam stress and perceived oral health status. Self-administered survey was conducted in total 304 students attending in academic high schools in Bucheon. For analysis, SPSS was used to perform t-test and one-way ANOVA. As a result of the study, the entrance exam stress level of academic high school students was 2.71. The level of sub-factors were that tension for exam/poor result was highest by 3.08 and the next were future uncertainty (2.81), parents pressure (2.56), and insufficient free time (2.52). The group with high entrance exam stress showed significantly high perceived degrees of temporomandibular disorder, oral mucosal disease and xerostama. Among sub-factors of stress, the group with high tension for exam/poor result stress had significantly high perceived degrees of dental caries, teporomandibular disorder, oral mucosal disease and xerostama. Because perception on oral health issues increased with high entrance exam stress in high school students, it is necessary to seek some ways to decrease oral health problems even though entrance exam stress is intensified. To do so, it is inferred that it will be very important to promote oral health education to develop ability of high school students to practice correct oral management method.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.3
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• pp.20-27
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• 2014

In the construction site, various earth retaining systems are developed and applied to maintain stability of excavated area and structures. Among the methods, the underground continuous wall and the column-type diaphragm wall methods are especially used in construction site nearby buildings or roads. However, these methods have some disadvantages such as the difficulty of quality control and long curing time because these methods need to cast fresh concrete at the construction site. In addition, these methods are usually applied to the site for the temporary purpose. In this paper, we suggest precast hollow prestressed concrete pile for continuous pile wall system. To investigate the structural behavior of suggested pile, which is the main member of the suggested system, tests pertaining to the structural behavior and prestressing force applied in the pile are conducted. From the test results, it was found that the prestressing force measured is sufficient compared with the value obtained by the design equation and the cracking moment measured is 34% higher than the design value. In addition to the above, this precast hollow prestressed concrete pile has an additional safety margin that the maximum moment is 59.2% higher than the cracking moment which is one of the serviceability limits for the design of the system.

• Knowledge Management Research
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• v.23 no.3
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• pp.259-284
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• 2022

In order to help the understanding of web novel users, this study was intended to quantitatively verify the user's behavioral types according to the characteristics of web novels. For this purpose, the direction of the study proceeded as follows. First, the motives of web novel users were investigated by referring to the motives of other digital content users. In addition, specific behavioral types of users were also collected. As a result, the motivation for using web novels was found to be 'interpersonal relationships and information acquisition with others', 'leisure activities', and 'escape from reality/relieve tension'. After that, the groups were classified as to whether there was a difference between groups according to the motives of use. As a result, the 'hobbies' type, a group with a particularly high motivation for using leisure activities, the 'stress relief' type, a group with very high escapism and tension relief characteristics, and a group with high interpersonal relationships and information acquisition with others The 'communication' type was classified as a 'multipurpose' type with high overall motivation characteristics. Then, in order to find out the specific characteristics between the types, personas were constructed based on the different behavior type data. Through this, the theoretical contribution of this study is meaningful in that it revealed the motives of web novel users. As a practical contribution, the persona was formed by combining the users' motives and behavioral patterns and visualized to be close to the actual representative users. These results are expected to help improve the web novel service by providing useful indicators for actual writers, platform managers, and users.

• Journal of Korean Society of Steel Construction
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• v.9 no.4 s.33
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• pp.697-705
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• 1997

The conventional preflex beams are designed by the method of paritial prestressing and allow the tensile stresses at the lower concrete of beams. As a consequence, most of preflex beams experience the tensile cracks under the service loads. This study was conducted to develop the most effective preflex beams, which do not allow tensile stress under the service load, by introducing additional prestressing called 'represtressing' at the lower concrete of beams. The objective of the study was accomplished by developing a computer analysis and design program and conducting experiments. Using the developed computer program, standard sections of the represtressed preflex beams were determined by computer modeling. In the experiment, two actual size of represtressed beams were tested under the imitated service loads. The results of test have shown that the performance of the represtressed preflex beams is generally excellent. A remarkable improvement was made in the design of preflex composite beams. Since the represtressed preflex beams(RPF) do not experience the tensile cracks under the service loads, the use of this beam for the bridge structures will lead to easy bridge maintenance and management. Furthermore, due to the low beam depth, high clearance and economical design can be realized in the bridge design using RPF.

• Journal of Service Research and Studies
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• v.12 no.2
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• pp.135-151
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• 2022

This study was conducted on a servicism basis as a study to build the management wisdom of Korea as an asset of human society. The case of the founding and development of the Republic of Korea, which developed into one of the world's leading powers with unprecedented rapid growth despite the devastating three-year war immediately after its founding, is an important subject of study. This study conducted a macroscopic analysis. In the process of carrying out the founding activities, it was confirmed that the original idea inherent in Koreans was the Taegeuk idea of the National Flag. The founders of the Republic of Korea consciously or unconsciously adopted the Taegeuk ideology as the founding ideology. It can be said that the Taegeuk ideology has led to greater success because it is based on the service philosophy, which is the common truth of mankind. In this study, the process of preparing for the founding of the Republic of Korea, which was founded by accepting a new maritime civilization from a country with a long continental civilization, the process of national foundation, and the process of operating the country after its founding were analyzed as a whole. In particular, it discovered the excellent wisdom of the founders who appropriately utilized the strengths of continental and maritime civilizations in necessary situations, and confirmed that the dynamic operating model of development through fierce competition between the two opponents was a success factor for high-speed national development. It requires great wisdom for Koreans with diverse ideological backgrounds and unique personalities to unite to establish and run a nation. This is because fierce competition and cooperation must be carried out at the same time. The great wisdom of the founding of the Republic of Korea was able to be demonstrated because the Taegeuk ideology was acting as a common basic ideology for Koreans. Taegeuk ideology, the source of wisdom that Korea has developed under constant tension, can be capitalized as human wisdom, and additional case studies are needed.

• Journal of the Korea Society of Computer and Information
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• v.25 no.9
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• pp.143-150
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• 2020

The purpose of this study is to investigate the human error of bodyguards caused in the process of performing access control activities between security missions, focusing on multiple risk cases, and to suggest countermeasures accordingly. To verify this, after arranging the sequence of events in a time series, the VTA technique and Why-Why analysis technique that can easily identify the problem centered on the variable node were used. In addition, environmental factors and personal factors that cause human errors were extracted through M-SHEL Metrix. As a result of analyzing multiple risk cases through such a method, the security environment factors that cause access control accidents include lack of time (impatience), prejudice against visitors, intensive work methods, lack of security management, unattended travel, and familiar atmosphere. (Relaxation), formal work activities, convenience provision, and underestimation were surveyed. In addition, human errors caused by personal security guards were investigated as low alertness, formal work, negligence of inspection, and comfortable coping.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.15 no.2
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• pp.93-97
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• 2015

Short-chain acyl-CoA dehydrogenase (SCAD) deficiency is an autosomal recessive hereditary metabolic disorder of mitochondrial fatty acid beta-oxidation. Mutations in the ACADS gene cause short-chain acyl-CoA dehydrogenase deficiency, which is characterized by developmental delay, hypotonia, seizure, and hypoglycemia. Here, we describe one Korean pediatric case of SCAD deficiency, which was diagnosed during newborn screening by tandem mass spectrometry and confirmed by molecular analysis. The level of C4 was typically elevated 5.23 mg/dL (reference range <1.5 mg/dL). This patient had a homozygous mutation [c.1031A>G, p. E344G] in ACADS. Therefore, we present a case of SCAD deficiency in an otherwise healthy neonate and her subsequent development and growth over four years.

• Journal of Korean Society of Steel Construction
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• v.18 no.6
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• pp.727-735
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• 2006

In this paper, a geometric nonlinear analysis procedure of the beam-column element including multi-noded cable element in extension of companion paper (Kim et al., 2005) is presented. First, a stiffness matrix was derived about the beam-column element that considers the second effect of the initial force supposing the curved shape at each time-step, with Hermitian polynomials as the shape function. Second, the multi-noded cable element was also subjected to the tangent stiffness matrix. To verify the geometric nonlinearity of this newly developed multi-noded cable-truss element, the Innovative Prestressed Support (IPS) system using this theory was analysed by geometric nonlinear method and the results were compared with those produced by linear analysis.

• Journal of the Korean Geotechnical Society
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• v.20 no.2
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• pp.107-113
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• 2004

A new innovative prestressed support (IPS) earth retention system has been developed and introduced. The IPS is a wale system prestressed by steel wires. The IPS consists of wale, wires, and H-beam support. The IPS provides a high flexural stiffness to resist the bending by earth pressures. The IPS earth retention system provides a larger spacing of support, economical benefit, construction easiness, good performance, and safety control. This paper explains basic principles and mechanism of new IPS system and presents a design method of IPS earth retention system. In order to investigate applicability and safety of new IPS system, field tests were performed in a trench excavation. The new IPS system applied in a trench excavation was performed successfully. The measured performances of IPS system were presented and discussed.

• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.229-236
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• 2005

To cope with increasing requirements of cost reduction, labor saving, and rapid construction, the purpose of this study is to investigate the structural behavior of PSC monolithic and spliced girders. Three tests were conducted on reduced-scale girder specimens having same type. This paper presents the result of experimental studies on the load-deflection behavior in which different joint and amount of tendon as major variables were investigated. The first one used a monolithic girder was arranged with three tendons. The second one used a spliced girder was joined with three tendons after producing five segments. And the third girder was produced in same conditions with the second girder and arranged with additional tendons. The experimental results show the difference of behavior between monolithic and spliced girders.