• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.25 no.4
• /
• pp.365-372
• /
• 2007

Enterprises requires the logistics information system to reduce logistics costs and ensure clearness of distribution. However, the system is adopted only by large corporations due to diversity of work and the initial cost for construction. In this study We have attempted to develop an information system capable of efficiently. Controlling and managing logistics by investigating division of duties and existing problem. Using small and medium-sized enterprises engaged in the distribution business as a model. For real-time monitoring of logistics information. We have constructed a system using new technologies such as GPS, mobile and wireless communications and made use of web GIS as infrastructure. Developed by the logistics information systems, We will control overall logistics work and reduce logistics costs and processing time as well.

• Journal of Cadastre & Land InformatiX
• /
• v.47 no.2
• /
• pp.145-157
• /
• 2017

Currently, the height of ships that can pass under Busan Harbor Bridge is limited to 60m or shorter, so that large-sized ships of 60m or taller cannot use Busan Harbor international passenger terminal. Accordingly, this study has developed a service which measures continuously the change of bridge height by water level changes and provides such in real-time for safe bridge passage of large-sized ships of 60m or taller. The measurement system comprised of high-precision laser distance measurement device, GPS sensor, optical module, and damping structure is used to measure the bridge height change according to tide level changes, and the measured information is provided in real-time through cloud-based mobile app. Also, in order to secure objective bridge height data for changes to height limits and navigation supports, the observation data was analyzed and forecast model was drawn. As a result, it became an objective evidence to revise the passage height rules of the Busan Port Bridge from 60 meters to 63 meters.

• Journal of Advanced Marine Engineering and Technology
• /
• v.18 no.5
• /
• pp.78-87
• /
• 1994

In this paper design and implementation of ship's distributed remote control system using dual-microprocessor is presented for real time process. The proposed system is implemented with the single chip microprocessors in tightly coupled mode and results in speed up of $s_p$=1.74. Under the assumption that the nodes are interconnected in multidrop, the overall system performance such as average throughout-delay characteristics and effective throughput are analyzed using M/G/1 queneing model, and results show that the proposed node can be used in medium sized distributed monitoring and control system.

• International Journal of Aeronautical and Space Sciences
• /
• v.6 no.2
• /
• pp.97-109
• /
• 2005

In this paper, the critical requirement for obstacle awareness and avoidance is assessed with the compliance of the equivalent level of safety regulation, and then the collision avoidance sensor system is presented with the key design parameters for the requirement of the smart unmanned aerial vehicle in low-altitude flight. Based on the assessment of various sensors, small-sized radar sensor is selected for the suitable candidate due to the real-time range and range-rate acquisition capability of the stationary and moving aircraft even under all-weather environments. Through the performance analysis for the system requirement, the conceptual design result of radar sensor model is proposed with the range detection probability and collision avoidance mode is established based on the time-to-collision, which is analyzed by collision scenario.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.22 no.3
• /
• pp.593-603
• /
• 1997

Connection admission decision in ATM networks requires decision made in real time using fast algorithm. It is difficult to construct a model of the multiplexed traffic and thus, approximation of the traffic load is necessary. In this paper, we propose a measurement-based dynamic CAC(Connection admission Control) in ATM(Asynchronous Transfer Mode) networks, which observes current traffic by the moving window and set the window size to the value which is computed from the measured cell loss amount. It is based on the measurements of the traffic load over an admission period that is load enough to reflect the current traffic behavior instead of analytic modeling. And, the dynamic reallocation of bandwidth for each class leads to effective bandwidth utilization. The performance of proposed method is analyzed through computer simulation. The performance of proposed method is analyzed by using SIMAN simulation package and FORTRAN language. As can be seen in the simulation result, cell loss performance and bandwidth utilization have been increased.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.18 no.33
• /
• pp.63-70
• /
• 1995

Most of small-to-medium sized companies use computer to manage and control their manufacturing system. However, it is real hard to find a company which uses the system properly. There are several reasons. First of all, appropriate software to satisfy user's needs is not available and there is lack of mind to computerize. Therefore, this paper focuses to show difficulties which they will encounter, develop a model of computerized production management system and define proper level of computerization. An experimental system has been developed for an auto-parts manufacturing company using IBM-PC in the environment of MS-DOS and CA-Clipper.

• Journal of information and communication convergence engineering
• /
• v.21 no.2
• /
• pp.117-129
• /
• 2023

High-utility itemset mining (HIUM) has emerged as a key data-mining paradigm for object-of-interest identification and recommendation systems that serve as frequent itemset identification tools, product or service recommendation systems, etc. Recently, it has gained widespread attention owing to its increasing role in business intelligence, top-N recommendation, and other enterprise solutions. Despite the increasing significance and the inability to provide swift and more accurate predictions, most at-hand solutions, including frequent itemset mining, HUIM, and high average- and fast high-utility itemset mining, are limited to coping with real-time enterprise demands. Moreover, complex computations and high memory exhaustion limit their scalability as enterprise solutions. To address these limitations, this study proposes a model to extract high-utility frequent closed itemsets based on an improved cumulative summary list structure (CSLFC-HUIM) to reduce an optimal set of candidate items in the search space. Moreover, it employs the lift score as the minimum threshold, called the cumulative utility threshold, to prune the search space optimal set of itemsets in a nested-list structure that improves computational time, costs, and memory exhaustion. Simulations over different datasets revealed that the proposed CSLFC-HUIM model outperforms other existing methods, such as closed- and frequent closed-HUIM variants, in terms of execution time and memory consumption, making it suitable for different mined items and allied intelligence of business goals.

• International journal of advanced smart convergence
• /
• v.12 no.4
• /
• pp.378-385
• /
• 2023

The importance of wearing respiratory protective equipment has been highlighted even more during the COVID-19 pandemic. Even if the suitability of respiratory protection has been confirmed through testing in a laboratory environment, there remains the potential for leakage points in the respirators due to improper application by the wearer, damage to the equipment, or sudden movements in real working conditions. In this paper, we propose a method to detect the occurrence of leak holes by measuring the pressure changes inside the mask according to the wearer's breathing activity by attaching an IoT sensor to a full-face respirator. We designed 9 experimental scenarios by adjusting the degree of leak holes of the respirator and the breathing cycle time, and acquired respiratory data for the wearer of the respirator accordingly. Additionally, we analyzed the respiratory data to identify the duration and pressure change range for each breath, utilizing this data to train a neural network model for detecting leak holes in the respirator. The experimental results applying the developed neural network model showed a sensitivity of 100%, specificity of 94.29%, and accuracy of 97.53%. We conclude that the effective detection of leak holes can be achieved by incorporating affordable, small-sized IoT sensors into respiratory protective equipment.

• Korea Real Estate Review
• /
• v.24 no.1
• /
• pp.15-26
• /
• 2014

Using multivariate GARCH model, we estimate the relationship between the housing sale prices and lease prices in the Korean housing market. In the analysis of relationship between the rate of changes in sale and lease prices, the correlation coefficient of the apartment and detached house is higher than that of the townhouse. By housing type, the correlation coefficient between detached house and townhouse is higher than between apartment and detached house or apartment and townhouse. By housing size, there are no significant different results between the sales price and the rental price. The correlation coefficient between medium and small size is the highest in the apartment housing market, whereas the correlation coefficient between large and medium size is the highest in the detached housing market, resulting from the fact that people may be more interested in medium- and small-sized apartment and large- and medium-sized detached house. In the detached housing market, the correlation coefficient between large-medium size and medium-small size in the rental price is higher than that of sales price. This result implies that the process of the decision making between purchasing and leasing a house might be different.

• Composites Research
• /
• v.18 no.4
• /
• pp.44-51
• /
• 2005

In this paper, we developed the direct numerical simulation(DNS) model considering the geometry of yams which consist of 3D orthogonal woven composite materials, and using this model, the dynamic behavior of under transverse low-velocity impact has been studied. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is presented and used in building structural plate model based on DNS. For comparison, DNS results are compared with those of the micromechanical approach which is based on the global equivalent material properties obtained by DNS static numerical tests. The effects with yarn geometrical irregularities which are difficult to consider in a macroscopic approach are also investigated by the DNS model. Finally, the multiscale model based on the DNS concepts is developed to enhance efficiency of analysis with real sized numerical specimen and macro/micro characteristics are presented.