• Structural Engineering and Mechanics
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• v.20 no.5
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• pp.505-526
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• 2005

The influence of the inter-story structural pounding on the seismic behaviour of adjacent multistory reinforced concrete structures with unequal total heights and different story heights is investigated. Although inter-story pounding is a common case in practice, it has not been studied before in the literature as far as the authors are aware. Fifty two pounding cases, each one for two different seismic excitations, are examined. From the results it can be deduced that: (i) The most important issue in the inter-story pounding is the local effect on the external column of the tall building that suffers the impact from the upper floor slab of the adjacent shorter structure. (ii) The ductility demands for this column are increased comparing with the ones without the pounding effect. In the cases that the two buildings are in contact these demands appear to be critical since they are higher than the available ductility values. In the cases that there is a small distance between the interacting buildings the ductility demands of this column are also higher than the ones of the same column without the pounding effect but they appear to be lower than the available ductility values. (iii) It has to be stressed that in all the examined cases the developed shear forces of this column exceeded the shear strength. Thus, it can be concluded that in inter-story pounding cases the column that suffers the impact is always in a critical condition due to shear action and, furthermore, in the cases that the two structures are in contact from the beginning this column appears to be critical due to high ductility demands as well. The consequences of the impact can be very severe for the integrity of the column and may be a primary cause for the initiation of the collapse of the structure. This means that special measures have to be taken in the design process first for the critically increased shear demands and secondly for the high ductility demands.

• Journal of Environmental Impact Assessment
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• v.5 no.2
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• pp.33-47
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• 1996

To select the criteria, literature review was made in the quantitative case of conservation biology, foreign country's EIA and domestic ecology. Among them, a few factors was extracted. To applicate the criteria to domestic forest ecosystem, expert opinion survey was executed to the ecologist. The results were summarized as follows; 1. Classification of sites was made of land use system which is related to forest ecosystem or forest conservation. Sites are divided into 3 categories which are nature preservation area, seminature preservation area and urbanized area. Evaluation criteria is consisted of rarity and naturalness. 2. Each area had different criteria composition according to the site characteristics. Criteria of nature preservation area is rarity in the broad sense (distribution pattern of vegetation), vegetation size, successional stage and depth of organic matters. Those of seminature preservation area are rarity in the broad sense (distribution area of vegetation), vegetation size, successional stage, diameter at breath height and depth of organic matters. And those of urbanized area are vegetation distribution in area, successional stage, age of forest and diameter of breath height. The basic data of criterion was gathered by field survey. 3. Evaluation index and total naturalness index was obtained by adding the each criterion. It is made up of two categories-rarity and naturalness. TNi is divided into 3 grades. Grade I is more than 70% for TNi, grade IT is 50~70%, and grade III is below 50%. According to the each grade, permitted action and facilities were suggested.. This research just focuses on the evaluation of vegetation quality and the assessment results do not directly judge conservation or development. To make better evaluation criteria, various fields of forest ecosystem-geological or physical nature environment and fauna ecosystem etc. -will be added wholly to this research.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.41-49
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• 2018

Recently, PPP (Public-Private-Partnership) Projects, which private companies invest in, plan, design, construct and operate, have become more popular around the world. The construction industry environment is becoming increasingly competitive. The PPP project is composed of various organizations, so it is very difficult to carry out the project successfully. In this environment, the construction companies are trying hard to secure a competitive advantage. In this study, we tried to identify the role of project manager's leadership and project citizenship behavior as a precedent for creating performance in PPP (Private-Public-Partnership) project. We examine the impact of PM's transformational leadership and transactional leadership on project citizen behavior and examine the impact of project citizen action on project management performance and completion performance. For this study, we conducted a questionnaire survey on PPP project participants. As a result, the following results were obtained. First, transformational leadership and transactional leadership had a significant influence on project citizenship behavior. Second, project citizen behavior had a significant impact on both project management performance and project completion performance. The idealized influence of transformational leadership and the Active management by exception of transactional leadership were found to be very important in shaping PPP team's project citizenship behavior. Therefore, this study has academic implications in studying the effects of PM leadership and project citizenship behavior on the performance of PPP project. And it is expected that it will help selection and training of PM to secure a competitive advantage for construction companies that implement PPP projects practically.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.51-56
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• 2013

From the time the product is manufactured until it is carried and ultimately used, the product is subjected to some form of handling and transportations. During this process, the product can be subjected to many potential hazards. One of them is the damage caused by shocks. In order to design a product-package system to protect the product, the peak acceleration or G force to the product that causes damage needs to be determined. When a corrugated fiberboard box loaded with products is dropped onto the ground, part of the energy acquired due to the action of the gravitational acceleration during the free fall is dissipated in the product and the package in various ways. The shock absorbing characteristics of the packaging cushion materials are presented as a family of cushion curves in which curves showing peak accelerations during impacts for a range of static loads are shown for several drop heights. The new method for determining the shock absorbing characteristics of cushioning materials for protective packaging has been described and demonstrated. It has been shown that cushion curves can be produced by combining the static compression and impact characteristics of the material. The dynamic factor was determined by the iterative least mean squares (ILMS) optimization technique in which the discrepancies between peak acceleration data predicted from the theoretical model and obtained from the impact tests are minimized. The approach enabled an efficient determination of cushion curves from a small number of experimental impact data.

• Journal of the Korea Society of Computer and Information
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• v.29 no.1
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• pp.231-239
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• 2024

This study was conducted with the purpose of understanding the factors that influence smartphone addiction on adolescents' school adaptation. The subjects were examined with a focus on students currently attending middle schools in Gwangju Metropolitan City, and data analysis was conducted using SPSS 26.0 to examine the factors influencing school adaptation, focusing on the inducements and forced inducements that lead teenagers to fall into smartphone addiction. As a result of the analysis, it was found that anonymity and desire satisfaction among the attractive factors leading to smartphone addiction have a negative impact on school adaptation, and the forcing factors that cause adolescents to become overly dependent on smartphones include online games, online chatting, online addiction, and social interaction. It was analyzed that both action and information search had a negative impact on adolescents' school adaptation. Based on the above results, policy recommendations were presented by considering the points pointed out by the two discovered factors.

• Ocean Systems Engineering
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• v.13 no.4
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• pp.349-365
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• 2023

Targeting a floating wave and offshore wind hybrid power generation system (FWWHybrid) designed in the Republic of Korea, this study examines the impact of the interaction, with multiple wave energy converters (WECs) placed on the platform, on platform motion. To investigate how the motion of WECs affects the behavior of the FWWHybrid platform, it was numerically compared with a scenario involving a 'single-body' system, where multiple WECs are constrained to the platform. In the case of FWWHybrid, because the platform and multiple WECs move in response to waves simultaneously as a 'multi-body' system, hydrodynamic interactions between these entities come into play. Additionally, the power take-off (PTO) mechanism between the platform and individual WECs is introduced for power production. First, the hydrostatic/dynamic coefficients required for numerical analysis were calculated in the frequency domain and then used in the time domain analysis. These simulations are performed using the extended HARP/CHARM3D code developed from previous studies. By conducting regular wave simulations, the response amplitude operator (RAO) for the platform of both single-body and multi-body scenarios was derived and subsequently compared. Next, to ascertain the difference in response in the real sea environment, this study also includes an analysis of irregular waves. As the floating body maintains its position through connection to a catenary mooring line, the impact of the slowly varying wave drift load cannot be disregarded. To assess the influence of the 2^nd-order wave exciting load, irregular wave simulations were conducted, dividing them into cases where it was not considered and cases where it was included. The analysis of multi-degree-of-freedom behavior confirmed that the action of multiple WECs had a substantial impact on the platform's response.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.125-134
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• 2017

Unusual precipitation caused by typhoons and severe rain stormscan threaten human life and property. Thus, various organizations prepare emergency action plans (EAPs) to provide proper guidelines for operators, experts, and emergency response personnel to protect and enhance critical infrastructure. For example, FEMA and DHS have various types of EAPs for dams, levees, and other structures to protect people and property. FEMA defines EAPs as official documents to decrease the damage and impact in emergency situations and to reduce casualties. These documents should consider all possible situations in an emergency and can reduce problems in facility management. This study analyzes EAPs for infrastructure from the USA, Japan, and Korea in order to suggest an ideal EAP framework. EAPcontent can include how to guide experts and operators in disaster stages (mitigation, preparedness, response, and recovery), how to operate emergency equipment, and how to protect critical infrastructure and life. The suggested EAP framework performed very well in a test location. It can therefore be used for infrastructure organizations in Korea and to inform of the appropriate processes and methods for risk reduction in flood disasters.

• Journal of the Korean Society of School Health
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• v.37 no.1
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• pp.1-11
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• 2024

Purpose: The purpose of the study was to conduct a descriptive survey to examine the knowledge, infection prevention behaviors, and health beliefs regarding COVID-19 and to identify factors that influence infection prevention behaviors in elementary and middle school students based on the Health Belief Model. Methods: The study included 388 elementary and middle school students in Seoul, Gyeonggi, and Jeonbuk provinces. Data were collected from September 1 to September 15, 2023. The questionnaire consisted of 10 questions about COVID-19 knowledge, 13 questions about infection prevention behaviors, and 15 questions about health beliefs. The collected data were subjected to multiple hierarchical regression analyses. The cronbach's α of infection prevention behaviors was 0.83, the KR-20 of COVID-19 related knowledge was 0.68, and the Cronbach's α of COVID-19 related health beliefs was 0. 78. Results: In Model 1, females showed higher levels of infection prevention behaviors than males (β=.14, p=.006) and middle school students showed lower levels of infection prevention behaviors than elementary school students (β=-.10, p=.037). In Model 2, among COVID-19-related health beliefs, barriers had a significant negative effect on infection prevention behaviors (β=-.20, p<.001) and cues to action had a significant positive effect on infection prevention behaviors (β=.14, p=.037), indicating that lower barriers and higher cues to action were associated with higher levels of infection prevention behaviors. Conclusion: The results showed that prevention behaviors were associated with lower barriers and higher cues to action among COVID-19 health beliefs. Elementary and middle school students in Korea spend a lot of time in groups at private academies or school, which are closed spaces with poor ventilation, making them vulnerable to new infectious diseases such as COVID-19. Unlike adults, infectious diseases can have serious impact on their mental and social health. Therefore, it is necessary for schools to provide accurate and timely health education about COVID-19 to increase cues to action for elementary and middle school students in order to improve their infection prevention behaviors.

• Journal of Navigation and Port Research
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• v.36 no.4
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• pp.321-327
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• 2012

Logistics in a supply chain network has become an important operational strategy in a competitive market. A number of internal and external risks involved in the logistics operations in a company tend to create problems in fulfilling customer orders. This research presents how ERM (enterprise risk management) can be used to identify, assess, and control logistics risks. An electronic company's logistics activities were used as an industry case to demonstrate a way to identify and assess risks surrounding global logistics function. This paper has further presented action plans to mitigate the impact of the risks that occur.

• Journal of Preventive Medicine and Public Health
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• v.53 no.4
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• pp.233-235
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• 2020

Since its early stages, the coronavirus disease 2019 (COVID-19) pandemic has posed immense challenges in meeting the public health and healthcare and social care needs of migrants. In line with other reports from United Kingdom and United States, data from Sweden's health authority show that migrants have been disproportionately affected by COVID-19. Following the World Health Organization's statements, as well as the European Public Health Association's call for action, several centres in Sweden's most populated areas have activated tools to implement national plans for community outreach through initiatives targeting migrants and ethnic minority groups. Unconventional means should be promoted to mitigate the impact of COVID-19 on migrants and the health of the public at large.