• Journal of the Korean Society for Railway
• /
• v.12 no.1
• /
• pp.55-64
• /
• 2009

Recently, concrete track is replacing ballast track for efficient and economic maintenance of track. It considerably offer less maintenance, a longer service life and reduced life-cycle costs. With the aim of achieving high-quality track construction work, of developing tools for quality assurance in new construction and for later technical inspection of material condition, a quality strategy has to be developed. For these purpose, NDT which is using the seismic wave has carried out in situ studies in the test construction section. The used NDT are SASW test, impact echo test and continuous impact echo test. The test is performed 5,353 times on 49 pre-cast concrete track panels to verify the stiffness structure and grouting efficiency of the track structure. To conclude, because of the non-homogeneous characteristic of concrete material. it is restricted to apply the elastic wave test at some aspect. However it is possible to acquisite a sufficient reliability about structural stiffness and grouting efficiency of concrete track.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.491-497
• /
• 2005

Brake system is indispensible functional part to the transportation machines such as railroad cars, and all of industrial machines. It is mechanical element to stop the movement or slow the speed, transforming kinetic energy of motion object into thermal energy through solid friction. According that recently the railroad cars have become high-speed, the technique in braking domain to secure the overall braking effort is making rapid progress. In particular, material development and manufacturing process are so important to secure friction performance, which is the core in braking performance of mechanical brake units. Wear of brake disk could mainly result in the diminishment of its life span due to thermal cracking, so the endurance against high temperature is required. On the other hand, in this case, the problem is that the side wear of pad, relative material is slightly increased because of enlargement of plastic deformation. It is necessary, therefore, to develop a disk material that will be used in the Tilting System mechanical brake units. The purpose of this paper is to make a study prior to developing brake disk of Tilting Train travelling at 200km/h and to propose the component of brake disk. Accordingly, I will conduct sufficient researches on technical documents of brake disk, that are basic documentations, analyze an impact on components, and further, considering braking degree of train, study for the basic proposal on brake disk's component of the train travelling at 200km/h, which has relatively minor influence of heat stress and maintains the friction. In this respect, I would like to investigate friction characteristics between disk and relative friction material via Test on some possible test segments, analyze and propose friction performance, temperature impact and so forth coming from the contact with pad, relative material to demonstrate the friction characteristics.

• Journal of Environmental Impact Assessment
• /
• v.11 no.3
• /
• pp.145-155
• /
• 2002

A substantial literatures on environmental risk perception have emerged since the late 1960s. Most these works focus on how people form risk perception, on what people believe, on difficulties in communicating information about health, safety, or environmental risks to non-experts. In this study, questionnaire surveys were conducted to sample from stakeholders(general public, environmental specialist, governmental official, non-government officials, journalist) during March and Aprils, 2000. Total number of responses was 1,803 including 773 persons of general public, 353 experts, 390 governmental officials, 111 journalists and 176 NGO members. Risk perception on 26 environmental issues were statistically analyzed to relate with the need to regulate each issues, interest and knowledge, experience of hazard, satisfaction in environmental situation, etc. This research aims to aid risk analysis and policy-making by providing a basis for understanding and anticipating group responses to environmental issues and improving the communication of risk information among general public, lay-people, technical experts, and decision-makers. This study concludes that those who are in charge of promoting and regulating health and safety of citizens should understand how people perceive about and respond to environmental risk. Without such understanding, well-intended environmental policies of governments would be ineffective.

• Journal of Internet Computing and Services
• /
• v.14 no.3
• /
• pp.23-33
• /
• 2013

Recently in the field of IT, cloud computing technology has been deployed rapidly in the current society because of its flexibility, efficiency and cost savings features. However, cloud computing system has a big problem of vulnerability in security. In order to solve the vulnerability of cloud computing systems security in this study, impact types of virtual machine about the vulnerability were determined and the priorities were determined according to the risk evaluation of virtual machine's vulnerability. For analyzing the vulnerability, risk measurement standards about the vulnerability were defined based on CVSS2.0, which is an open frame work; and the risk measurement was systematized by scoring for relevant vulnerabilities. Vulnerability risk standards are considered to suggest fundamental characteristics of vulnerability and to provide the degree of risks and consequently to be applicable to technical guides to minimize the vulnerability. Additionally, suggested risk standard of vulnerability is meaningful as the study content itself and could be used in technology policy project which is to be conducted in the future.

• Journal of the Society of Naval Architects of Korea
• /
• v.49 no.6
• /
• pp.478-483
• /
• 2012

The speed performances of ice sea trial on the Arctic(2010 & 2011) area were shown different results depend on the ice floe size. Penetration phenomena of level ice was not happened on medium ice floe and tore up by the impact force because the mass of medium ice floe is similar to the mass of Araon which is Korean ice breaking research vessel and did not shut up by the ice ridge or iceberg. The sea trial on the Amundsen sea was performed at the big floe which is classified by WMO(World Meteorological Organization). Three measurements of ice properties and five results of speed trial were obtained with different ice thicknesses and engine powers. To evaluate speed of level ice trial and model test results at the same ice thickness and engine power, the correction method of HSVA(Hamburg Ship Model Basin) was used. The thickness, snow effect, flexural strength and friction coefficient were corrected to compare the speed of sea trial. The analyzed speed at 1.03m thickness of big floe was 5.85 knots at 10MW power and it's 6.10 knots at 1.0m ice thickness and the same power. It's bigger than the results of level ice because big floe was also slightly tore up by the impact force of vessel based on the observation of recorded video.

• Korean Journal of Metals and Materials
• /
• v.48 no.12
• /
• pp.1047-1055
• /
• 2010

The objective of this study is to investigate the ballistic properties of Zr-based amorphous alloy surface composites fabricated by high-energy electron-beam irradiation. The mixture of Zr-based amorphous powders and $LiF+MgF_2$ flux powders was deposited on a pure Ti substrate, and then an electron beam irradiated this powder mixture to fabricate a one-layer surface composite. A four-layer surface composite, in which the composite layer thickness was larger than 3 mm, was also fabricated by irradiating the deposited powder mixture by an electron beam three times on the one-layer surface composite. The microstructural analysis results indicated that a small amount of fine crystalline particles were homogeneously distributed in the amorphous matrix of the surface composite layer. According to the ballistic impact test results, the surface composite layers effectively blocked a fast traveling projectile, while many cracks were formed at the composite layers, and thus the surface composite plates were not perforated. The surface composite layer containing ductile ${\beta}$ dendritic phases showed a better ballistic performance than the one without dendrites because dendritic phases hindered the propagation of shear bands or cracks.

• Trans-
• /
• v.8
• /
• pp.79-93
• /
• 2020

The main purpose of this article is to discuss the impact of "Dance Smash" TV show on Chinese dance, which uses the combination of dance and new media technology as the core content of the program. "Dance Smash", as a dance communication TV program for the public, first considers the entertainment attributes of variety shows. Spread the dance art on the basis of meeting the public's aesthetic needs, thereby expanding the popular living space of dance art. The use of 'moment of the storm' has let the general audience of non-dance majors feel the technical charm of dances, thus playing a healthy promotion role. However, whether "Bullet Time", a type of dance program that has had a successful case in the West, can also have a positive impact on the mass communication of dance in the localization of China, this is what questions and seeks of this article.

• Journal of Digital Convergence
• /
• v.19 no.9
• /
• pp.349-360
• /
• 2021

The purpose of this study is to verify whether social support for single parents in leisure, culture, and info-communication areas has the moderating effect on the impact of stress situations on academic continuity in single parents. To this end, technical statistics and logistic analysis were conducted on 248 single parents who were pregnant or pregnant at the age of 18 or older and raised their children after childbirth. As a result, one out of every four beneficiaries were involved, increasing the possibility of academic continuation by adjusting the stress-induced tendency of single parents to stop studying due to leisure, culture, and information and communication expenses. These results show that leisure, culture, and information and communication support are effectively contributing to improving the academic sustainability of single parents who want to stop studying due to stress relief and stress. Therefore, it is necessary to strengthen leisure, culture, and social support in the information and communication sectors for the academic continuation of single parents of teenagers.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.4
• /
• pp.146-159
• /
• 2018

This study analyzed what premium features significantly affect customer satisfaction and their recommendation, and what factors significantly affect product attributes. In the process, first, the loyalty program and the customer compensation program were studied to determine the impact of the customer satisfaction and recommendation. The study analyzed that quality and design of product properties had significant effects on all factors, but the brand was not significantly affected. Second, while superiority, differentiation and scarcity of luxury items are significant to customer satisfaction but superiority is only significant in relation to recommendation intention. Third, the preceding study shows that the customer compensation program has a significant impact on sales growth, but the study found that it was not for imported luxury car customers. Fourth, if the royalties program is low in awareness, it has been analyzed that the scarcity and customer satisfaction relationships among luxury goods have been adjusted. On the contrary, if there is a high level of awareness, it is analyzed that there is a control effect customer satisfaction and differentiation among luxury brands. In the conclusion, in order to satisfy customers at the import luxury car market, the differentiation of luxury goods by standard index must be strengthened and the brand must be strengthened among the attributes of the product. In addition, by raising awareness of the royalties program, the relationship between differentiation and customer satisfaction can be enhanced.

• Human Ecology Research
• /
• v.56 no.6
• /
• pp.507-525
• /
• 2018

This study examines the consumer empowerment index for Chinese elderly consumers, the impact of socio-demographic variables, exposure to mass media, and communication about consumption on consumer empowerment. The consumer empowerment index is composed of three factors: consumer knowledge, consumer attitude, and consumer skill. Data were collected from 301 Chinese elderly consumers aged 60 to 80 years old via a professional online survey firm. The findings of the analysis were described using frequency, t-test, ANOVA, and multiple regression analysis. The results are as follows. First, the average of consumer knowledge was 35.69 points out of 100, consumer skill was 65.71 points, and consumer attitude was 68.87 points. Second, socio-demographic variables indicated that education level, previous occupation, type of residence and communication about consumption impact consumer empowerment. Elderly consumers with higher education had higher consumer attitudes and better overall consumer empowerment than those with lower education. Consumers who were self-employed workers had higher consumer skills than those of technical or service workers. Elderly consumers who live alone had higher consumer skills than those who live in a nursing home. Third, according to communication about consumption, family communication is positively associated with consumer attitudes, skills and overall empowerment, while friend communication is positively associated with consumer attitudes and overall empowerment. The findings of this study are useful in developing guidelines that help the government make consumer education systems for the elderly who want to improve consumer empowerment levels evenly among these factors.