• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.5 no.4
• /
• pp.720-740
• /
• 2011

Wi-Fi-enabled portable devices have recently been introduced into the consumer electronics market. These devices download or upload content, from or to a host machine, such as a personal computer, a laptop, a home gateway, or a media server. This paper investigates the fairness among multiple Wi-Fi-enabled portable devices in a home network when they are simultaneously communicated with the host machine. First, we present that, a simple IEEE 802.11-based home network suffers from unfairness, and the fairness is exaggerated by the wireless link errors. This unfairness is due to the asymmetric response of the TCP to data-packet loss and to acknowledgment-packet loss, and the wireless link errors that occur in the proximity of any node; the errors affect other wireless devices through the interaction at the interface queue of the home gateway. We propose a QoS-provisioning framework in order to achieve per-device fairness and service differentiation. For this purpose, we introduce the medium access price, which denotes an aggregate value of network-wide traffic load, per-device link usage, and per-device link error rate. We implemented the proposed framework in the ns-2 simulator, and carried out a simulation study to evaluate its performance with respect to fairness, service differentiation, loss and delay. The simulation results indicate that the proposed method enforces the per-device fairness, regardless of the number of devices present and regardless of the level of wireless link errors; furthermore it achieves high link utilization with only a small amount of frame losses.

• 한국HCI학회:학술대회논문집
• /
• 2006.02a
• /
• pp.711-716
• /
• 2006

Since the introduction of digital camera to the mass market, the number of digital photos owned by an individual is growing at an alarming rate. This phenomenon naturally leads to the issues of difficulties while searching and browsing in the personal digital photo archive. Traditional approach typically involves content-based image retrieval using computer vision algorithms. However, due to the performance limitations of these algorithms, at least on the casual digital photos taken by non-professional photographers, more recent approaches are centered on time-based clustering algorithms, analyzing the shot times of photos. These time-based clustering algorithms are based on the insight that when these photos are clustered according to the shot-time similarity, we have "event clusters" that will help the user browse through her photo archive. It is also reported that one of the remaining problems with the time-based approach is that people perceive events in different scales. In this paper, we present an adaptive time-based clustering algorithm that exploits the usage history of digital photos in order to infer the user's preference on the event granularity. Experiments show significant performance improvements in the clustering accuracy.

• The Journal of the Korea Contents Association
• /
• v.17 no.3
• /
• pp.486-495
• /
• 2017

The purpose of this study is to investigate the effect of information education satisfaction of the elderly welfare center on information utilization satisfaction and life satisfaction of the elderly. For this purpose, we surveyed the elderly who were enrolled in the elderly welfare center from September 02 to September 24, 2015. First, in the information cognition improvement of the elderly, it was found that the content of education of information, education instructor, and educational environment are important. And in the improvement of the information experience of the elderly, it was found that the education contents, the education method, the instructor and the educational environment factors of the satisfaction of information education were important factors. Second, in the improvement of personal factors satisfaction of the elderly, it was found that the content of education of information and education and the factors of education instructor were important factors. The purpose of this study was to investigate the relationship between information literacy and satisfaction of the elderly.

• Korean Journal of Cognitive Science
• /
• v.24 no.2
• /
• pp.95-109
• /
• 2013

With the rapid evolution of the personal device environment, the demand for natural language applications is increasing. This paper proposes a morpheme segmentation and part-of-speech tagging model, which provides the first step module of natural language processing for many languages; the model is designed for mobile devices with limited hardware resources. To reduce the number of morpheme candidates in morphological analysis, the proposed model uses a method that adds highly possible morpheme candidates to the original outputs of a conventional left-longest-match-preference method. To reduce the computational cost and memory usage, the proposed model uses a method that simplifies the process of calculating the observation probability of a word consisting of one or more morphemes in a conventional hidden Markov model.

• The Journal of the Korea Contents Association
• /
• v.17 no.2
• /
• pp.160-171
• /
• 2017

This study is intended to study the usage of augmented reality(AR) in the marketing field by classifying them into display and content types and analyzing the typical cases and characteristics. The market for AR has been on the increase and has been a big influence in the marketing field, resulting in the generalization of the term "AR marketing." By analyzing the marketing cases which use AR technology and organizing the frequency of use and characteristics, it is expected to contribute as a basic material for future studies on AR marketing. In this study, AR marketing cases are classified into different categories including display and contents. First, AR display category includes personal computers, mobile, public display, and projection display. AR contents category includes informative content, game contents, virtual experience, and visual effect. While investigating, it was found that the most used type of AR display was mobile, which has the advantage of not being limited by time and place and is also capable of one-on-one marketing with customers. The most used type of AR content was visual effect type, which evokes curiosity and is easily shared among people.

• Journal of the Korean Society for information Management
• /
• v.37 no.1
• /
• pp.127-151
• /
• 2020

The court has the responsibility to determine the final interpretation of the law. The court hands down final decisions on personal disputes and conflicts between individuals and the state. Legal commentaries will stay true to their intention of providing diverse legal theories and enabling a unified legal interpretation only when law practitioners are allowed to discuss in depth laws, cases, and legal theories within the boundaries set by commentary authors. If law practitioners include the latest laws, cases, and legal theories as well as their opinions to existing commentaries in their judicial roles and legal studies, they will be able to obtain a unified legal interpretation without referring to other legal literature.

• Journal of Advanced Navigation Technology
• /
• v.15 no.3
• /
• pp.378-385
• /
• 2011

This paper introduces technical aspects of the privacy exposure problem of the video and the audio information on the personal computer and proposes a countermeasure to them. According to the increased number of peripherals for computers, especially including the cameras and the mikes, it is required to be careful on the privacy exposure. Currently, some incorporated or standalone cameras have a pilot lamp to indicate their usage. However, many other cameras and all mikes have not equipped with the pilot lamp or other dedicated indicator. Even though this problem doesn't obstruct their assigned functionalities, it should make the devices susceptible to be exposed with the information they are gathering without any notice to the owners. As a countermeasure to the problem, this paper proposes a reasonable solution that alarms the access trials to the devices and implements programs for the practical sniffing and its counterpart.

• KIEAE Journal
• /
• v.15 no.3
• /
• pp.37-42
• /
• 2015

Purpose: Apartment is a typical residential type in Korea. In the past, apartment types were very monotonous. But today, the types of complex are changed because personal needs have been diversified and personalized. In order to meet those needs, construction companies are constructing various types of apartments. The more apartment types are diverse, the more the energy problems are taken place. So, the purpose of this study is to solve the problem of energy gap in the same complex through improving the thermal transmittance of wall. Method: Heating energy consumption of Building Energy Efficiency Rating System and heating energy usage of apartment show a similar trend on the graph. In order to identify the best position of heating energy consumption difference reduction, we change the building's U-value of front, back, side walls. Result: In the A complex, maximum and minimum heating energy consumption building's shapes are flat. the best efficiency is side U-value change and the worst is front change. In the E complex, maximum heating energy consumption building's shape is tower and minimum building shape is flat. Consequently, the front and back wall performance change was little effect to reduce energy gap, while the change of side wall's U-value show the great reduction between building's energy consumptions.

• Journal of environmental and Sanitary engineering
• /
• v.14 no.4
• /
• pp.85-92
• /
• 1999

Indoor air quality tends to be the dominant contributor to personal exposure because most people spend over 90% of their time indoors. For some contaminants, exposure to indoor air poses a potentially greater health threat than outdoor air exposures. Indoor nitrogen dioxide ($NO_2$) levels are mainly affected gas range, flue gas spillage, kerosene heaters, wood-burning appliances and cigarette smoke. In addition, indoor $NO_2$ levels are influenced by such house characterization as surface reaction and air exchange rate. In this study, the measurements of indoor and outdoor $NO_2$ concentrations were taken using identical protocols, and information was collected on housing characteristics using identical questionnaires in 14 houses out of 15 houses for daily 30 daily 30 days in Brisbane, Australia.The usage of gas range was the most contributing factor in indoor $NO_2$ concentration in relation to house characteristics. Average indoor and outdoor ratios of NO2 concentration in electronic and gas cooking houses were $0.6{\pm}0.1$ and $0.9{\pm}0.2$, respectively. The frequency distributions of $NO_2$ concentration in each house were approximately log-normal Geometric mean of indoor $NO_2$ concentrations of electronic and gas cooking houses for daily 30 days ranged from 2.5 ppm to 11.5 ppm with a mean 6.8 and from 4.7 ppm to 28.6 ppm with a mean 15.6 ppm, respectively. The $NO_2$ concentrations between electronic and gas cooking houses were significantly different (p<0.05). Since each house has different life-style and house characteristics, sampling interval to measure the $NO_2$ levels was recommended above 7 days.

• Journal of Convergence Society for SMB
• /
• v.5 no.3
• /
• pp.1-7
• /
• 2015

Recently, finance technology related to Fin-Tech has emerged while national and international financial incidents have increased. Security technologies that are currently operated in the financial institutions, have been reported to be vulnerable to security attacks. In this paper, we propose a method of response and plan of security incident using Fin-Tech technology in the divers authentication methods and the usage of biometrics. Proposed method provides a convenient banking services to the users by integrating IT technology, such as personal asset management, crowdfunding to finance technology. Also, the proposed method may provide the security with ease by applying the security technologies such as PCI-DSS, tokenization technique, FDS, the block chain. Proposed method analyzes a number of security cases in relation to the Fin-Tech, financial technologies, for a response.