• The Magazine of the IEIE
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• v.23 no.12
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• pp.115-125
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• 1996

This paper presents a new algorithm for the self-localization of a mobile robot using one degree perspective Invariant(Cross Ratio). Most of conventional model-based self-localization methods have some problems that data structure building, map updating and matching processes are very complex. Use of a simple cross ratio can be effective to the above problems. The algorithm is based on two basic assumptions that the ground plane is flat and two locally parallel sloe-lines are available. Also it is assumed that an environmental map is available for matching between the scene and the model. To extract an accurate steering angle for a mobile robot, we take advantage of geometric features such as vanishing points. Feature points for cross ratio are extracted robustly using a vanishing point and intersection points between two locally parallel side-lines and vertical lines. Also the local position estimation problem has been treated when feature points exist less than 4points in the viewed scene. The robustness and feasibility of our algorithms have been demonstrated through real world experiments In Indoor environments using an indoor mobile robot, KASIRI-II(KAist Simple Roving Intelligence).

• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.1C
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• pp.25-34
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• 2004

In mobile agent environments, cascaded delegations among places occur frequently due to the mobility of agents. Cascaded delegation in mobile agent environments can be defined as the process whereby the delegated place delegates the rights of the delegating place further. The representative study for delegation in mobile agent environments is Berkovits et al.'s study. Their study only defines the messages that is sent between the place executing the agent and the place where the agent migrates. Because their study considers only the delegation between two places which participate in migration of an agent, it is inadequate in the situation that the cascaded delegation is necessary. In other words, the relationships among the messages sent from and to places is necessary. However, their study does not exist the relationships. In this paper, we propose a delegation scheme that provides agents with secure cascaded delegation. The proposed scheme achieves the goal by nesting each delegation token within the signed part of the next immediate delegation token. We prove that the proposed scheme is secure against the attack of replaying a message and of substituting a delegation token.

• Journal of Internet Computing and Services
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• v.5 no.1
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• pp.99-111
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• 2004

Two general security measures in computing networks are secure data transmission and user authentication, These problems are still critical in the wireless LAN environments. Thus security becomes most significant issue in personal network environments and ubiquitous networks based on wireless LANs. We purpose a new authentication system for these kind of environments, and coined it UPMA(Ubiquitous Personal Mutual Authen-tication) model. UPMA supports authenticating configurations which provides personal verification for each system. It guarantees secure communications through the session key setup, and provides mutual authentication by verifying each user and his/her station. UPMA solves security problems in ubiquitous networks without accessing authentication server, Instead it performs mutual authentication between terminals or between systems. It is a global authentication system which enables global roaming service through the Internet or other public networks, It can be used to guarantee safe and convenient access to a company Intranet or to a home network.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.12
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• pp.1282-1287
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• 2001

This study presents the numerical analysis of natural convection of a micro- environments with air permeability in the clothing air-layer. As a numerical model the clothing air layer of shoulder and arm were adopted. Finite volume method for two-dimensional laminar flow was used for the analysis of flow and thermal characteristics of velocity, temperature and concentration in the air layer between body and clothing. As temperature boundary conditions, a body skin has a high temperature with $34^{\circ}C$ and the environmental temperatures are 5, 15 and $25^{\circ}C$ for various permeability coefficients. The distributions of concentration, temperature and velocity are shown that two large cells form at horizontal and vertical air layer, respectively. As the temperature difference between body skin and environment decreases, the heat transfer is decreased rapidly.

• ALGAE
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• v.26 no.3
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• pp.243-251
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• 2011

Environmental conditions can influence the morphology of local biota through phenotypic plasticity or local adaptation. Macroalgal morphologies are often associated with wave-exposure conditions. We investigated the relationship between morphology and wave exposure in two common endemic subtidal macroalgae, Carpophyllum angustifolium and C. maschalocarpum, from the East Cape of New Zealand. Morphological comparisons were made between individuals from two sites and four different wave-exposure zones, as defined by fetch and barnacle composition. Of the seven morphological traits measured in C. angustifolium, only total length varied, and individuals were longer in more wave-exposed environments between the two exposure zones where the species were found. In contrast, total length, stipe thickness and vesicle presence all varied significantly between exposure zones in C. maschalocarpum. C. maschalocarpum specimens were shorter with thinner stipes, and fewer individuals had vesicles in the more wave-exposed zones. Morphological traits of both species also varied between sites, suggesting that other influences are important for determining species morphology. Further study is needed to investigate the role of phenotypic plasticity and genetic variability for driving morphological variation in C. angustifolium and C. maschalocarpum.

• Proceedings of the Korea Society of Information Technology Applications Conference
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• 2005.11a
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• pp.365-368
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• 2005

While the goal of new IT adoption in small and medium sized firms is to choose an optimal system to fit with their own environments and conditions, that of IT post-adoption usage is to fully implement new IT and maximize their benefits from it. Therefore, the decision-making environments of new IT adoption is definitely different from those of post-adoption. Also, The direct experience of IT usage can provide some learning effect and the change of users' beliefs on new IT. From this point of view, this study attempts to figure out the differences of influencing factors on IOS usage intention between adopters and non-adopters. The results show that there are clear differences of influencing factors between two groups. Non-adopter group shows that perceived financial cost and ability of use have significant influences on IOS usage intention, while relative advantage and perceived risk in adopter group have statistically significant influences on post-adoption usage of IOS.

• Korea Trade Review
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• v.44 no.2
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• pp.221-237
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• 2019

Multinational corporations (MNCs) usually face indigenous business environments in host countries which are different from a home country's. In this circumstance, MNCs would accomplish low-investing performance if they pursuit the same as the home oriented business strategy in the host country. The more different kinds of specialized environments a host countries have, the more pressure of modifying the international strategy needed for MNCs. This paper examines that how a different market environment between a home country and a host country, through MNC's local responsive managements, can influence investing performance in a host country. This paper conducts structural equation analyses with collected empirical data focusing upon a MNC's market orientation efforts and the realization of management localization (i.e., increasing local sourcing intensity or local sales intensity) as mediators between the specialized environment in a host country and the MNC's investing performance. This paper has several contributions in developing the prior approaches: first, the market orientation variables are regarded not as normal independent factors but mediators; second, two step mediation model is examined to make link between host market's heterogeneity and MNC's performance.

• Human Ecology Research
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• v.62 no.2
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• pp.317-326
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• 2024

This study evaluated the thermal physiological and psychological responses elicited when wearing cold protective jackets with aerogel fillings in two cold environments, one without air velocities and one with air velocities (2.3 m·s-1), at an air temperature of 10℃. The participants were five healthy young males. Measures were taken of physiological parameters, blood pressure (BP), heart rate (HR), core temperature, oxygen uptake (Vo2), and microclimate (temperature and humidity). The psychological parameters evaluated were thermal and wetness sensation. No differences were observed in systolic blood pressure, heart rate, and oxygen intake between the conditions. At tympanic temperature, a significant difference was observed between the conditions during exercise (p<.05); . A significant difference was observed in the microclimate temperature of the clothing according to the airflow, and temperature changes in the chest and back revealed different patterns. Significant differences were observed in thermal sensation (whole body (p<.05), chest (p<.05), back (p<.01)) between airflow conditions. The results therefore indicate that cold protective jackets with an aerogel filling are suitable for people operating in low-temperature and airflow environments.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.5
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• pp.77-88
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• 2022

This study aims to understand the relationship between the distribution of fish species in the two water ecosystems and the habitat factors according to the survey period targeting Gwanggyo Lake Park in the city. There are studies on the appearance and distribution of species by applying eDNA to freshwater ecosystems. However, in the domestic, streams are the target, and studies on the relationship between species distribution and habitat environment in two water environments are lacking. We conducted to analyze the species list and relationship with habitat factors using eDNA research in May and October at 21 points in Gwanggyo Lake Park, Suwon City, which were connected to lakes and streams. As a result, there was no species difference in the water environment according to the survey period. However, the total number of reads during the spawning season(May) was 3,126,482, which was more than double that after the spawning season(October). Tolerant species appeared in Woncheon Lake with a slow or stagnant flow, but there was no significant correlation between species and habitat factors depending on the survey period. On the other hand, intermediate and sensitive species appeared in the Woncheon stream with high flow. There was a significant correlation between the low temperature during the spawning season and the high dissolved oxygen content after the spawning season(P<0.001, Tem.: 20.7±2.6℃, DO: 8.6±1.7). It is expected that environmental DNA will be used to survey species and suggest monitoring methods according to the survey period.

• Journal of the military operations research society of Korea
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• v.10 no.2
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• pp.51-59
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• 1984

Military personnel encounter a variety of noise environments. During exercises, high intensity noise levels are often encountered. Twenty-four subjects were required to respond to symbols presented under two levels of task difficulty, two levels of presentation rate, two levels of display orientation, and three levels of noise intensity. The purpose of the experiment was to determine whether noise intensity and display orientation had any effect on a short-term memory task. Results showed that continuous white noise at intensity levels of 30, 85, and 105 db had no effect on the shortterm memory task. Presentation rate and task difficulty demonstrated a significant relationship with task performance as did their two-way interaction. This two-way interaction between presentation rate and task difficulty exhibited a different pattern for the two levels of display orientation.