• Smart Structures and Systems
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• v.15 no.3
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• pp.627-643
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• 2015

Negative stiffness, previously emulated by active or semi-active control for cable vibration mitigation, is realized passively using a self-contained highly compressed spring, the negative stiffness device (NSD).The NSD installed in parallel with a viscous damper (VD) in the vicinity of cable anchorage, enables increment of damper deformation during cable vibrations and hence increases the attainable cable damping. Considering the small cable displacement at the damper location, even with the weakening device, the force provided by the NSD-VD assembly is approximately linear. Complex frequency analysis has thus been conducted to evaluate the damping effect of the assembly on the cable; the displacement-dependent negative stiffness is further accounted by numerical analysis, validating the accuracy of the linear approximation for practical ranges of cable and NSD configurations. The NSD is confirmed to be a practical and cost-effective solution to improve the modal damping of a cable provided by an external damper, especially for super-long cables where the damper location is particularly limited. Moreover, mathematically, a linear negative stiffness and viscous damping assembly has proven capability to represent active or semi-active control for simplified cable vibration analysis as reported in the literature, while in these studies only the assembly located near cable anchorage has been addressed. It is of considerable interest to understand the general characteristics of a cable with the assembly relieving the location restriction, since it is quite practical to have an active controller installed at arbitrary location along the cable span such as by hanging an active tuned mass damper. In this paper the cable frequency variations and damping evolutions with respect to the arbitrary assembly location are then evaluated and compared to those of a taut cable with a viscous damper at arbitrary location, and novel frequency shifts are observed. The characterized complex frequencies presented in this paper can be used for preliminary damping effect evaluation of an adaptive passive or semi-active or active device for cable vibration control.

• Journal of Advanced Navigation Technology
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• v.15 no.5
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• pp.742-748
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• 2011

G-File on the position of the photo shoot pictures with built-in picture file to the user, the location and orientation of the image files using the data refers to the [1]. G-File is to store photo files, photo files and receiving means for receiving input, and picture files, photos and location information extracted by separating the subject's location information with location information and location analysis by means of the corresponding coordinates on the map including the location indicated in the guide means is characterized in that. In this paper, the G-File on the location information stored in the algorithm that can be managed is proposed. G-File on the algorithm used to manage the information to the user, G-File management is to provide convenience.

• Journal of Advanced Navigation Technology
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• v.13 no.2
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• pp.272-279
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• 2009

A location information used in LBS provides convenience to the user, but service provider can be exploited depending on how much risk you have. Location information can be exploited to track the location of the personal privacy of individuals because of the misuse of location information may violate the user can import a lot of damage. In this paper, we classify the life cycle of location information as collection, use, delivery, storage and destroy and analyze the factors the privacy is violated. Furthermore, we analyze information security mechanism is classified as operation mechanism and policy/management mechanism and propose a security solutions of all phase in life cycle.

• Journal of Communications and Networks
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• v.7 no.2
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• pp.207-221
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• 2005

The proliferation of wireless local area networks (WLANs) offering high data rate in hot spot area have spurred the demand for possible WLANs and third-generation (3G) cellular network integration solutions as the initiative step towards 4G systems. This paper provides a novel architecture for seamless location-aware integration of WLANs into 3G cellular networks and also an analysis for the efficient handover techniques. We introduce location as a key context in secure roaming mechanism for context-aware interworking in 4G systems. The fast secure roaming with location-aware authentication is implemented at an entity called location-aware service (LAS) broker that utilizes the concepts of direction of user and pre-warming zone. The location-ware interworking architecture supports seamless roaming services among heterogeneous wireless networks including WLANs, wireless metropolitan area networks (WMANs), and 3G cellular networks. This paper also includes a description of procedures needed to implement efficient mobility and location management. We show how the LAS broker with pre-warming and context transfer can obtain significant lower latency in the vertical handover.

• Journal of Fashion Business
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• v.9 no.4
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• pp.16-29
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• 2005

The purpose of this study is to evaluate the differences of visual image by variations in the location of the waistline and width of the belt of the basic skirt. The stimuli are 21 samples: 7 variations of the location of the waistline and 3 variations of the width of the belt. The data has been obtained from 43 fashion design majors. The data has analyzed by frequency, factor analysis, anova, scheffe's test and the MCA method. The results of this study are as follows. The visual image by variations of the location of the waistline and width of the belt is composed of 3 factors: attention, function, attraction. The visual image by variations of the width of the belt has partial significant differences. The visual image by variations in the location of the waistline has significant differences in all factors. Function shows the interaction between the location of the waistline and width of the belt. However, attention and attraction don't show the interaction between the location of the waistline and width of the belt ; the location of the waistline tends to be the main effect.

• The Journal of the Korea Contents Association
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• v.15 no.2
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• pp.101-108
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• 2015

Location-sharing based service (LSBS) refers to a service that users share their location information with other users with whom friendship. At this time, the location information is shared through service provider, and then their position information is exposed to the service provider. The exposure of this personal position information to the service provider has raised a privacy problem, and thus privacy preserving mechanisms have been proposed to protect them. In this paper, we examine the types and features of the proposed location-sharing based services so far, and survey the research trend of privacy preserving mechanisms for them. Through the analysis on existing privacy preserving mechanisms, we present design factors for a privacy preserving mechanism for the current LSBS services, and suggest future work.

• ETRI Journal
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• v.33 no.4
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• pp.528-536
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• 2011

In this paper, we analyze the location accuracy of real-time locating systems (RTLSs) in multipath environments in which the RTLSs comply with the ISO/IEC 24730-2 international standard. To analyze the location error of RTLS in multipath environments, we consider a direct path and indirect path, in which time and phase are delayed, and also white Gaussian noise is added. The location error depends strongly on both the noise level and phase difference under a low signal-to-noise ratio (SNR) regime, but only on the noise level under a high SNR regime. The phase difference effect can be minimized by matching it to the time delay difference at a ratio of 180 degrees per 1 chip time delay (Tc). At a relatively high SNR of 10 dB, a location error of less than 3 m is expected at any phase and time delay value of an indirect signal. At a low SNR regime, the location error range increases to 8.1 m at a 0.5 Tc, and to 7.3 m at a 1.5 Tc. However, if the correlation energy is accumulated for an 8-bit period, the location error can be reduced to 3.9 m and 2.5 m, respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.3
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• pp.601-606
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• 2019

The lenticular Location Based System is related to a location information technology. The system enables users to inform their location in real time wherever in a room, a building, a ship, a basement. In this paper, we analyze limitations and problems of the existing indoor Positioning System and propose a method of user-oriented location service. The proposed method consists of a lenticular sticker, a database(DB) acquisition and analysis technology. The proposed system can be used as an infrastructure to implement various indoor location-based services. In addition to improve user centered positioning accuracy through the development of location-based systems using indoor lenticular systems, it can be used in a disaster situation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.30 no.1
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• pp.1-9
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• 2018

Thermal performance of a heat sink for an inverter power stack was analyzed in terms of array and installation location of an Insulated Gate Bipolar Transistor (IGBT). Thermal flow around the heat sink was calculated with a numerical model that could simulate forced convection. Thermal performance was calculated depending on the array and location of high- and low-power IGBTs considering the maximum temperature of IGBT. The optimum array and installation location were found and causes were analyzed based on results of numerical analysis. For the numerical analysis, experiment design considered the installation location of IGBT, ratio of heat generation rates of high- and low-power IGBTs, and velocity of the inlet air as design variables. Based on numerical results, a correlation that could calculate thermal performance of the heat sink was suggested and the maximum temperature of the IGBT could be predicted depending on the installation method.

• Journal of Navigation and Port Research
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• v.39 no.5
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• pp.423-429
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• 2015

The expansion on the scale of international trade and rapid economic growth in Northeast Asia have caused intense competition among global companies for securing international logistics center in Northeast Asia. Analyzing location competitiveness for international logistics center in Northeast Asia, this paper aims to extract implications for enhancing locational competitiveness. Employing the relative importance among location selection factors extracted from AHP analysis in prior study, we evaluated the major five port-cities in Northeast Asia including Busan, Gwangyang, Shanghai, Qingdao and Tokyo. In the evaluations, Shanghai (3.926) ranked as the first, followed by Busan (3.859), Qingdao (3.555), Tokyo (3.013) and Gwangyang (2.915). Furthermore, the causal relationships between determinants for location choice decision (logistics factor, cost factor, market factor, service factor and environmental factor) and dependent variables (competitiveness of international logistics center, potentiality to growth, present intention to move into and future plan to move into) were analyzed to provide implications. Results provide useful insights for further improvements, and helps strategic agenda for future development of port-cities.