• Transactions of the Korean Society of Machine Tool Engineers
• /
• v.12 no.1
• /
• pp.92-100
• /
• 2003

Using a quarter car model, an analytic method for performance estimation of a vehicle suspension system with respect to frequency response, RMS response and performance index is presented. From frequency response function, compromization of response performance to the whole frequency range is verified and from RMS response and performance index, sensitivity of ride md handling characteristics are examined. Using a full car model, sweet area(stable ride area) are determined and performance sensitivity is estimated according to the change of feedback gains. In order to esimate the output sensitivity, response we is displayed using a 3-dimensional contour plot. Design data n suggested for optimal design parameter esimation, which maximize the performance of the given suspension system.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.26 no.11
• /
• pp.1488-1495
• /
• 2002

The response time represents how fast a system responds to a given disturbance at the system boundary. Flow restricting devices for controlling transients can result in a decrease in the peakm pressure, but may change response time. Response lag in a hydraulic system leads to inefficient working cycle and operator discomfort. The experiments were conducted in order to get information on the parameters which exert appreciable influence on the response time. The experimental apparatu including a hydraulic actuator, orifice and a hydraulic pump was an idealization of a bucket hydraulic shifting system. Experimental results show that the response time depends on operating pressure and flow rate. The effects of orifice type and size on the response time are quantified.

• Proceedings of the KSME Conference
• /
• 2001.11b
• /
• pp.597-603
• /
• 2001

Control of pressure transients in a hydraulic system may be important and necessary to avoid failures and to improve the efficiency of operation. Flow restricting devices can result in a decrease in the peak pressure, but may change the response time. The response time has an important effect on both operator and operator perceived smoothness. The response time should correspond to how fast a system responds to a given disturbance at the system boundary. Occasionally the appropriate response time is not easily determined. This study is on the response time characteristics in the hydraulic system studied for the control of response time.

• Asian Journal for Public Opinion Research
• /
• v.1 no.2
• /
• pp.128-146
• /
• 2014

Incentives are often included in survey design because they are known to improve response rates, at least moderately. This paper describes the changes in the response rates when incentives were introduced into a longitudinal survey. The National Survey of Student Engagement was conducted annually at Indiana University Bloomington from 2000 through 2012. In 2010, incentives were introduced in an attempt to reverse the declining response rates. The incentives performed as expected, raising the AAPOR Response Rate 3 from 24% in 2009 to 36% in 2010. From 2010 through 2012, different types of incentives were tried but the response rates did not change substantially. The results from the changes in incentives can help survey practitioners decide the number and types of incentives that might be used effectively to increase response rates.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.2
• /
• pp.171-179
• /
• 2023

Due to man-made climate change, global abnormal weather phenomena have occurred, increasing disasters. Major developed countries(military) are preparing for disasters caused by extreme weather appearances. However, currently, disaster prevention plans and facilities have been implemented based on the frequency and intensity method based on statistical data, it is not enough to prepare for disasters caused by frequent extreme weather based on probability basis. The U.S. and British forces have been the fastest to take research and policy approaches related to climate change and the threat of disaster change, and are considering both climate change mitigation and adaptation. The South Korean military regards the perception of disasters to be storm and flood damage, and there is a lack of discussion on extreme weather and disasters due to climate change. In this study, the process of establishing disaster management systems in developed countries(the United States and the United Kingdom) was examined, and the response policies of each country(military) were analyzed using literature analysis techniques. In order to maintain tight security, our military should establish a response policy focusing on sustainability and resilience, and the following three policy approaches are needed. First, it is necessary to analyze the future operational environment of the Korean Peninsula in preparation for the environment that will change due to climate change. Second, it is necessary to discuss climate change 'adaptation policy' for sustainability. Third, it is necessary to prepare for future disasters that may occur due to climate change.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• v.2 no.2
• /
• pp.82-95
• /
• 2021

Current international negotiation and cooperation for sustainable development are focused on three main themes. The first theme is implementation of Sustainable Development Goals (SDGs). The second theme is development of measures for climate change. The third theme is sustainable management of biodiversity and ecosystem services. In South Korea, responses of government policies and academic studies have been predominantly to one of these three themes. There have not been many integrated efforts to develop countermeasures considering all three international themes. In addition, while "green growth" policies have been setting national agendas for Korea's sustainable development, they must be scrutinized such as why they have not dealt with some parts of these three themes and whether they have ignored one of these themes due to lack of integrated responses. This study finds critical issues in South Korea on how to harmoniously respond to the three themes of international efforts and improve green growth policies. First, to achieve SDGs, the domestic statistical system must be reorganized to track the achievement of "inclusiveness" and "green growth". Second, the climate change response policy should seek inclusion between countries and between social groups. Third, in the field of biodiversity and ecosystem services, it is necessary to establish Korea's identity in global geopolitics and enhance its own traditional ecological knowledge. Fourth, it is necessary to consider how to solve discrepancy between climate change response policies and biodiversity-ecosystem service management policies. Finally, proactive improvement of laws and institutions must occur to promote inclusive green growth.

• Korean Journal of Ecology and Environment
• /
• v.56 no.4
• /
• pp.393-405
• /
• 2023

This study was conducted to select indicators for assessing national biodiversity. For this purpose, 140 biodiversity-related indicators were identified as a result of inventorying biodiversity-related indicators used in Korea and abroad, and when these indicators were applied to the pressure, status, and response indicator system, it was found that status indicators accounted for the largest number of indicators, with 29 pressure, 59 status, and 44 response. We also categorized the status indicators into genes, species, habitat, function, and quality, and found that species and habitat indicators accounted for the majority. Pressure indicators were categorized into direct exploitation, pollution, alien species, climate change, and habitat change. As a result, it was found that direct exploitation and pollution accounted for most of the pressure indicators. In addition, this study used internationally used indicator selection criteria to establish criteria for selecting domestic biodiversity assessment indicators. Using this list of indicators and indicator selection criteria, we evaluated the prioritization of domestically applicable biodiversity indicators through relevant expert consultations. 1) Vegetation class, 2) Land cover indicators, and 3) Change of protected area ranked highly. In fact, these indicators have been used in many studies due to the availability of assessable data. However, most of the highly scored indicators are based on ecosystem area, and further consideration of ecosystem functions and components(species) is needed.

• 한국전산유체공학회:학술대회논문집
• /
• 2003.10a
• /
• pp.46-47
• /
• 2003

Direct numerical simulations are performed for a turbulent flow subjected to a sudden change in pressure gradient. The calculations are started from a fully-developed turbulent channel flow at $Re_{\tau}=180$. The pressure gradient of the channel flow is then changed abruptly. The responses of the turbulence quantities (e.g., turbulence intensities, Reynolds shear stress, and vorticity fluctuations) and the near-wall turbulence structure to the pressure gradient change are investigated. It is found that there are two different relaxations: a fast relaxation at the early stage and a slow one at the later stage. The early response of the velocity fluctuations shows an anisotropic response of the near-wall turbulence.

• International Commerce and Information Review
• /
• v.10 no.3
• /
• pp.459-474
• /
• 2008

Under violent competition to secure international raw materials, safe supply and demand of crude oil that only relies on import among main raw materials is an important task for Korean economic development. Therefore, this study aims to analyze the impact of price change of international crude oil on merchandise balance. It also presents political suggestions in preparation for national economic development and safety and develops an organized and long-term overseas resources development program. As the time-series data which had the 1st difference contribute to dismissal of the null hypothesis successfully, we carry out a multivariate cointegration test developed by Johansen (1988) and find that at least one cointegration vector exists. And, when Impulse Response Function is introduced, as the crude oil import price shows a negative impact from Step 2, then an extreme change, a positive impact since Step 13, is maintained and a safe result appears.

• Asia pacific journal of information systems
• /
• v.33 no.3
• /
• pp.603-623
• /
• 2023

While prior work has conducted individuals' password security behavior, there is a relatively neglect to examine individuals' affect and feelings of password fatigue in password change context. Therefore, this study explicated individuals' affective response to the feelings of password fatigue by drawing on several theoretical lens. Survey data collected from 267 users were used to test the model using partial least square analysis. This study found that feelings of password fatigue positively affected the negative password fatigue-induced affect, and also both the feelings of password fatigue and the negative password fatigue-induced affect were negatively related to attitude toward changing passwords, which in turn, leads to the intention to change passwords. Furthermore, this study found that shadow work recognition negatively moderated the relationship between attitude and behavioral intention. This study could offer a new theoretical perspective to understand an individual's security behavior and provide empirical evidences for practitioners in charge of IT security in organizations.