• Journal of the Korea Institute of Building Construction
• /
• v.17 no.1
• /
• pp.1-8
• /
• 2017

Recently, because of the terrorisms or warfare, the damages of human life or facilities have been increased. Hence, the Korean government launched the research group for high performance fiber reinforced cementitious composite (HPFRCC) with increased demanding on protecting and anti-explosive structures. Therefore, in this research, to apply the HPFRCC on military facilities with optimum performance on workability and performance, the fundamental properties and reduction of autogenous shrinkage of HPFRCC with various combinations of steel and organic fiber and emulsified refined cooking oil (ERCO) were evaluated. As a result, based on the comprehensive analysis, for favorable workability, strength, and autogenous shrinkage, 1.5 % of combined fiber of short steel fiber and long organic fiber and 0.5 % of ERCO was suggested as an optimum conditions.

• The KSFM Journal of Fluid Machinery
• /
• v.17 no.1
• /
• pp.5-11
• /
• 2014

The purpose of this paper is to investigate an analytical approach for opening performance evaluation of the nuclear pressure safety valve based on standard codes such as ASME or KEPIC. It is well-known that safety valve is considered as one of pressure relief valves for protecting a boiler or pressure vessel from exceeding the maximum allowable working pressure. When pressure in a container reaches its set pressure, the safety valve commences discharging the internal fluid by a sudden opening called as popping. Safety valve is usually evaluated by set pressure, full open, blow-down, leakage and flow capacity. The test procedure and technical requirement for performance evaluation is described in international code of ASME code such as BPVC. The opening characteristics of steam safety valve can be analyzed by computational fluid dynamics (CFD) and steam shaft dynamics. First, the flow analysis along opening process is simulated by running the CFD models of the ten types of opening steps from 0 to 100%. As a analysis result, the various CFD outputs of flow pattern, pressure, forces on the disc and mass flow at each simulation step is demonstrated. The lift force is calculated by using the forces applied on disc from static pressure and secondary flow. And, the effect of huddle chamber or control chamber is studied by dynamic analysis based on CFD simulation results such as lift force. As a result, dynamics analysis shows opening features according to the sizes of control chamber.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3210-3222
• /
• 2010

Franchise Industry has a big portion in national economy, and contributes to protecting self-employments and making jobs. One of good way to increase the success of franchise business is operating some franchisor's company owned outlets before franchising. The purpose of this research is to understand the effects of the company owned outlets on franchisor's current performance. According to the result, the operation term, scale, and location of company owned outlet increase the legitimacy of franchisor. The operation term, and scale of company owned outlet increase the efficiency of franchisor, And both legitimacy and efficiency increase of franchisor's current achievement.

• Journal of the Korea Society of Computer and Information
• /
• v.15 no.9
• /
• pp.99-107
• /
• 2010

This paper showed that the integrated system to fortify security was much more efficient than the respective system through the analysis of problems from Firewall and IPS system in the existing security systems. The results of problem analysis revealed that there were the delay of processing time and lack of efficiency in the existing security systems. Accordingly, their performance was evaluated by using the separated Firewall, IPS system, and the integrated system. The result of evaluation shows that the integrated security system this paper suggested is five times faster than the existing one in terms of processing speed of response. This paper demonstrated the excellence of the proposed security system is also more than fivefold in session handling per second and six times process speeding in the CPU processing performance. In addition, several security policies are applied, and it provided a fact that it gave an excellent performance when it comes to protecting from harmful traffic attacks. In conclusion, this paper emphasized that fortifying the integrated security system was more efficient than fortifying the existing one considering in various respects such as cost, management, time, space and so on.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.183-183
• /
• 2023

Smart water cities (SWC) are urban municipalities that utilizes modern innovations in managing and preserving the urban water cycle in the city; with the purpose of securing sustainability and improving the quality of life of the urban population. Understanding the different urban water characteristics and management strategies of cities situate a baseline in the development of evaluation scheme in determining whether the city is smart and sustainable. This research herein aims to develop measurements and evaluation for SWC Key Performance Indicators (KPIs), and set up a unified global standard and certification scheme. The assessment for SWC is performed in technical, as well as governance and prospective aspects. KPI measurements under Technical Pillar assess the cities' use of technologies in providing sufficient water supply, monitoring water quality, strengthening disaster resilience, minimizing hazard vulnerability, and maintaining and protecting the urban water ecosystem. Governance and Prospective Pillar on the other hand, evaluates the social, economic and administrative systems set in place to manage the water resources, delivering water services to different levels of society. The performance assessment is composed of a variety of procedures performed in a quantitative and qualitative manner, such as computations through established equations, interviews with authorities in charge, field survey inspections, etc. The developed SWC KPI measurements are used to evaluate the urban water management practices for Busan Eco Delta city, a Semulmeori waterfront area in Gangseo district, Busan. The evaluation and scoring process was presented and established, serving as the basis for the application of the smart water city certification all over the world. The established guideline will be used to analyze future cities, providing integrated and comprehensive information on the status of their urban water cycle, gathering new techniques and proposing solutions for smarter measures.

• Journal of Korea Multimedia Society
• /
• v.14 no.3
• /
• pp.356-367
• /
• 2011

In this paper, we proposed a new car engine sealing inspection system based on image processing and understanding. The car engine sealing inspection plays very important role for protecting leakage caused by inappropriate sealing, which is a crucial point for productivity of car engines. The proposed inspection system has been aimed to enhance the previously proposed sealing inspection systems based on image processing, which have high computation complexity and low performance for correctly inspecting some contamination by oil with similar color with that of sealing. Moreover, the previously proposed system has a difficulty in installing the camera system on the sealing machine. The proposed system considers a difference of images before and after sealing obtained from one static camera. By utilizing a difference of images, the proposed system shows very robust performance using a proposed simple depth checking algorithm for some contamination cases by oil with similar color with that of sealing and the total inspection system is simple and cheap to implement. According to the experiments conducted in a real car product line, the proposed inspection system shows better inspection performance and needs smaller implementation cost than three other previously proposed system working in current car sealing inspection systems.

• Journal of the Korean Geotechnical Society
• /
• v.37 no.10
• /
• pp.5-11
• /
• 2021

The compacted bentonite buffer is one of the most important components in an engineered barrier system (EBS) to dispose of high-level radioactive waste (HLW) produced by nuclear power generation. The compacted bentonite buffer has a crucial role in protecting the disposal canister against the external impact and penetration of groundwater, so it has to satisfy the thermal-hydraulic-mechanical requirements. Even though there have been various researches on the investigation of thermal-hydraulic properties, few studies have been conducted to evaluate mechanical properties for the compacted bentonite buffer. For this reason, this paper conducted a series of unconfined compression tests and obtained mechanical properties such as unconfined compressive strength, elastic modulus, and void ratio of Korean compacted bentonite specimens with different water content and dry density values. The unconfined compressive strength and elastic modulus increased, and the Poisson's ratio decreased a little with increasing dry density. It showed that unconfined compressive strength and elastic modulus were proportional to dry density. However, there was not a remarkable correlation between mechanical properties and water content.

• Journal of Information Management
• /
• v.40 no.3
• /
• pp.61-77
• /
• 2009

Recently, enterprises are protecting information assets with the various means of control and management. Nevertheless, they are confronted with the dilemma which the higher securitylevel they request, the lesser efficiency and productivity in short terms they acquire by the inconvenience of business process. In addition, in spite of the steady increase of organization's investment on information protection, the systematic way for the performance measurement of information protection has not been suggested, so that in reality, it is difficult to make the decision to invest on information-protection and elicit the direction to improve it. For this reason, this study intended to establish the concept of the protection and security of information assets of enterprises and to categorize the type of activities to protect information assets into management activity and control activity, and analyze the effects of management activity and control activity for information asset protection on the performance of information asset protection activity and organization. For this research, questionnaire survey was conducted with literature study and the PLS(Partial Least Square) was used to analyze the measurement model and hypotheses testing. The PLS analysis results indicate that management activity for information asset protection affects information asset protection performance. Further, organizational performance is influenced by information asset protection performance. Practical implications of these findings and future research implications are also discussed.

• International Journal of Computer Science & Network Security
• /
• v.23 no.5
• /
• pp.163-171
• /
• 2023

The intelligent transportation system has made a huge leap in the level of human services, which has had a positive impact on the quality of life of users. On the other hand, these services are becoming a new source of risk due to the use of data collected from vehicles, on which intelligent systems rely to create automatic contextual adaptation. Most of the popular privacy protection methods, such as Dummy and obfuscation, cannot be used with many services because of their impact on the accuracy of the service provided itself, they depend on changing the number of vehicles or their physical locations. This research presents a new approach based on the shuffling Nicknames of vehicles. It fully maintains the quality of the service and prevents tracking users permanently, penetrating their privacy, revealing their whereabouts, or discovering additional details about the nature of their behavior and movements. Our approach is based on creating a central Nicknames Pool in the cloud as well as distributed subpools in fog nodes to avoid intelligent delays and overloading of the central architecture. Finally, we will prove by simulation and discussion by examples the superiority of the proposed approach and its ability to adapt to new services and provide an effective level of protection. In the comparison, we will rely on the wellknown privacy criteria: Entropy, Ubiquity, and Performance.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
• /
• 1996.04a
• /
• pp.88-96
• /
• 1996

The characteristic analysis of fly ash generated from a fired power plant using bunker-C oil has been investigated. Ash size distribution by an optical microscopy with image processing technique, morphological shape by a scanning electron microscope(SEM) and microscope, chemical composition by the inductively coupled plasma emission spectrometry(ICP), and resistivity measurement as a function of temperature and moisture content by the resistivity meter are performed. A study of physical, chemical and electrical characteristics of bunker-C fly ash plays an important role of improving the performance of an electrostatic precipitator and protecting air pollution. The samples of bunker-C fly ash for analysis were collected from the electrostatic precipitator hopper of Ulsan Power Plant Unit 1 and Pusan Power Plant Unit 1. Mass median diameter(MMD) of bunker-C fly ash was measured 12.7${\mu}{\textrm}{m}$, while MMD of fly ash generated from the mixture of bunker-C oil(40%) and domestic anthracitic coal(60%) was 25.7${\mu}{\textrm}{m}$. The morphological structure of bunker-C fly ash consisted of fine particles of non-spherical shape. The primary chemical components of bunker-C fly ash were composed of SiO2(2.36%), Al2O3(4.91%), Fe2O3(14.33%) and C(11.84%). Resistivity of bunker-C fly ash was found to be increased with increasing temperature at the range of 100~15$0^{\circ}C$ and was measured 103~104 ohm-cm.