• Journal of the Korea Society of Computer and Information
• /
• v.19 no.5
• /
• pp.71-78
• /
• 2014

The RFID-tag objects can be recognized by a distinct reader where it is installed. The RFID-tag objects are likely described as storages rather than the mobiles in the use of GPS. As RFID tags are large in number compared to moving objects, so the storing and retrieval costs are highly expensive. Here, two solutions for spatio-temporal model taking account of the feature in the tagged objects are proposed. First, the moving-tag objects are expressed by the terms "now" as well as "path location". Second, the size of storing index was noticeably reduced by not saving the tag information of palletizing products but mapping the tagged objects.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.37 no.7
• /
• pp.9-17
• /
• 2000

Determining the position and velocity of mobiles is an important issue for efficient handoff and channel allocation in microcell structure. Our early work proposes a technique for estimating the mobile location in the microcellular architecture. This process is based on the three step position estimation which determines the mobile position by gradually reducing the area of the mobile position. Using three step method, the estimator first estimates the locating sector in the sector estimation step, then estimates the locating zone in the zone estimation step, and then finally estimates the locating block in the block estimate step. But this scheme is prone to errors when the mobile is located in the boundary of sectors or tracks. In this paper we propose the enhanced scheme to reduce the estimation error.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.25 no.10A
• /
• pp.1512-1520
• /
• 2000

The wireless communication network is evolving toward IMT-2000 for providing various multimedia services. In order to accomplish this ultimate goal the effective schemes are required which can dynamically utilize the limited wireless resources based on different traffic characteristics of various services. This paper proposes a novel bandwidth allocation and call admission control scheme to transmit multimedia traffic based on the bandwidth reservation procedure using direction estimation in the IMT-2000 This scheme estimates the position of mobiles based on the mliticriteria decision making in which uncertain parameters such as RSS(Received Signal Strength), the distance between mobile and base station the moving direction and the previous location are participated in the decision process using aggregation function in fuzzy set theory. Its effectiveness is investigated by simulation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.41 no.10
• /
• pp.1186-1189
• /
• 2016

A distributed uplink power control algorithm based on flocking model is proposed to improve the energy efficiency of mobiles station (MS) in cellular networks. As each bird in a flock matches its velocity with the average velocity of the adjacent birds, each MS in a cell matches its uplink rate with the average uplink rate of the co-channel MSs in adjacent cells by controlling its transmission power. Results show that the proposed algorithm effectively reduces the power consumption in the MS, while maintaining a low outage probability, which eventually improves the energy efficiency of the MS.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.22 no.7
• /
• pp.57-62
• /
• 2014

This study presented the feasibility of a coolant heat-source heat pump system as an alternative heating system for electrically driven vehicles. Heat pumps are among the most environmentally friendly and efficient heating technologies in residential buildings. In various countries, electric mobiles devices such as EV, PHEV, and FCEV, have been mainly concerned with heat pumps for new mobile markets. The experiments herein were conducted for various ambient temperatures and coolant temperatures to reflect the winter season. The system, a coolant heat-source heat pump, consisted of an inside heat exchanger, an outside heat exchanger, a motor driven compressor, an electronic expansion valve, and plumbing parts. For the experimental results, the maximum heating capacity and air discharge temperature are up to 6.3 kW and $62^{\circ}C$ respectively at an ambient temperature of $10^{\circ}C$, and coolant at $10^{\circ}C$. However, at $-20^{\circ}C$ ambient temperature and $-10^{\circ}C$ coolant temperature, conditions were insufficient to warm the cabin as the air discharge temperature was $13^{\circ}C$.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.13 no.4
• /
• pp.107-113
• /
• 2017

Open platform technology in the banking industry is anticipated to impact the market very positively together with the activation of Fin Tech services. The domestic environment of payment services has been rapidly changing into the mobiles and multiple new payment services have been introduced from a variety of vendors. However, the convenience of payment always causes worsening the security, and the accidents on the security have been continued to occur such as leakage of personal information, hacking and so on upon the expansion of the industry and the market size. This study aims to analyze the status of Fin Tech open platforms and various problems of the related standard technologies, and to suggest the possible solutions. Upon the analysis results, it was confirmed that multiple solutions were required to improve the main security protocols of open platforms and to process the security functions diversely. In conclusion, the results of this study will be helpful to determine the direction of the solution on the security issues in the open platform environment of the current industry.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.5 no.1
• /
• pp.59-64
• /
• 2002

Passive sonar system forms the various beams in any desired directions to obtain the improvement in Signal-to-Noise(S/N) ratio, bearing detection and localization of targets, and the attenuation of interferences from other directions. Detection of modern underwater targets is becoming increasingly difficult as noise reduction technology leads to considerably low-level acoustic emissions. Therefore, the improvement of beamforming is very important to detect modern underwater targets at the long range in the complex environmental sea. Also, to react to the fast attack mobiles such as torpedoes, port and starboard discrimination is required to be performed very quickly. In this paper, we proposed the implementation of omnidirectional target bearing detector without port and starboard ambiguity to detect effectively the low-level underwater targets. The port and starboard discrimination is performed by cardioid processing and the improvement of beamforming utilizes the cross correlation matrix of individual hydrophone pairs of linear array sensors. The sea test result shows that the system implemented is good for the detection of the low-level underwater targets.

• Journal of the Korean Society for Precision Engineering
• /
• v.29 no.7
• /
• pp.799-804
• /
• 2012

Recently micro-nano structures has widely been reported to improve the performance of waterproof, heat isolation, sound and light absorption in various fields of electric devices such as mobiles, battery, display and solar panels. A lot of micro-sized holes on the surface of thin film provide excellent sound, or heat, or light transmission efficiency more than solid film and simultaneously nano-sized protrusions around micro hole increase the hydrophobicity of the surface of thin film because of lotus leaf effects as generally known previously. In this paper new rapid fabrication process with 355 nm UV laser ablation was proposed to get micro-nano structures on the surface of thin film, which have only been observed at higher laser fluence. Developed thin micro-nano structured film was also investigated the hydrophobic property by measuring the contact angle and demonstrated the possibility to apply to water droplet separation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.189-191
• /
• 2014

Todays, with the spread of Mobile devices, game industry has experienced the change of supply chain structure and paradigm. Breaking the traditional supply chain of game industry, mobile games of App. markets provide alternatives or threats against traditional game industry. With the mobility as a strongpoint, mobile games have their own characteristics such as convenience, easy of use and simplicity comparing PC games or other games. In this point, this study is to find success factors of mobiles games through the analysis on the highly ranked favorite games according to the types of mobile games.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2014.05a
• /
• pp.538-541
• /
• 2014

With the increased market demand for advanced specifications in smart phones, smart phones that have functions with wireless communications with high speed, cameras with high pixel and with high graphic processing ability have appeared. Furthermore, as traditional Augmented Reality technology has been practicable in mobile devices, many application's use AR technology, so AR's portability has been increased. But application with AR technology, which was implemented in smart phones has created capacity issues as applications are taking up a large portion of the memory capacity of phones. This research designed and implemented optimized AR technology by Mixare, AR open source, to solve such problems. As a result, I assured that there has been a decrease in application's memory used on the basis of mobiles.