• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.211-235
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• 2004

Component based design is perceived as a key technology for developing advanced real-time systems in a both cost- and time effective manner. Already today, component based design is seen to increase software productivity, by reducing the amount of effort needed to update and maintain systems, by packaging solutions for re-use, and easing distribution. Nowdays, a thousand and one companies in If(Information Technology) industry such as Sl(System Integration) and software development companies, regardless of scale of their projects, has spent their time and endeavor on developing reusable business logic. The component software is the outcome of software developers effort on overcoming this problem; the component software is the way propositioned for quick and easy implementation of software. In addition, there has been lots of investment on researching and developing the software development methodology and leading If companies has released new standard technologies to help with component development. For instance, COM(Component Object Model) and DCOM(Distribute COM) technology of Microsoft and EJB(Enterprise Java Beans) technology of Sun Microsystems has turned up. Component-Based Development (CBD) has not redeemed its promises of reuse and flexibility. Reuse is inhibited due to problems such as component retrieval, architectural mismatch, and application specificness. Component-based systems are flexible in the sense that components can be replaced and fine-tuned, but only under the assumption that the software architecture remains stable during the system's lifetime. In this paper, It suggest that systems composed of components should be generated from functional and nonfunctional requirements rather than being composed out of existing or newly developed components. about implements and accomplishes the modeling for the Product Control component development by applying CCD(Contract-Collaboration Diagram), one of component development methodology, to MRP(Material Requirement Planning) System

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.9B
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• pp.876-882
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• 2009

In this paper, we propose a sub-cell coverage control algorithm for enhancement of the cell throughput in OFDMA based relay systems. Relay station (RS) is exploited for improved quality of the received signal in cellular communication systems, especially in shadow areas. However, since a RS requires additional radio resource consumption for the link between the base station (BS) and the RS, we have to carefully control the coverage areas if a mobile station (MS) is serviced via the BS or the RS considering the cell throughput. We consider radio resource reuse as well for the sub-cell coverage configuration by applying various reuse patterns between RSs. We also consider a time varying system by adaptively changing the threshold for coverage depending on the MSs' traffic in the cell. We initially determine the sub-cell coverage of the system depending on the ratio of received signal-interference-noise-ratio (SINR) of the MS from the BS and RSs, respectively. Then, the "sub-cell coverage threshold" varies based on the "effective transmitted bits per sub-channel" with time. Simulation result shows that the proposed "time varying coverage control algorithm" leads to throughput improvement compared to the fixed sub-cell coverage configuration.

• Journal of Bio-Environment Control
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• v.33 no.2
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• pp.114-119
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• 2024

Rockwool substrate has superior physicochemical characteristics and is often used in crop cultivation. However, rockwool substrate has the disadvantages of high purchase cost and difficulty in disposal. Reuse of substrate can compensate for these disadvantages. Substrate must be disinfected and rehydrated during reuse, and various physicochemical changes during this process must also be considered. This study was to compare the physical properties of two types of rockwool substrates (reused and unused) and to evaluate the reuse potential of rockwool substrate by analyzing the chemical properties of the reused rockwool substrate during the rehydration process. The experiment on substrate physicochemical properties comparison was conducted from March to August 2023 using used rockwool substrates in tomato cultivation and unused rockwool substrates. Drainage time, drainage volume, and substrate weight were measured using load cells installed at the top and bottom of the irrigation monitoring system. The reused rockwool substrate weight and density were higher than those of the unused rockwool substrate, while the average drainage time after irrigation was 1.5 times longer for the reused rockwool than for the unused rockwool. The salinity concentration in different parts of the reused rockwool substrate was found to be lower in the reused rockwool substrate compared to the unused rockwool substrate. The electrical conductivity of the drainage was at its peak at the beginning of the drainage and decreased exponentially as the drainage volume increased. Change in electrical conductivity of the drainage over the irrigation time showed an exponential decay pattern. Through the experiments, the potential reusability of the rock wool substrate was assessed by conducting a comparative analysis of its physicochemical properties.

• The Journal of Information Systems
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• v.22 no.1
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• pp.1-27
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• 2013

The advancement of information and communication technology have brought the increase and the diversification of the digitalized information, which can be shared at any time from any place. Especially, with the recent spread of smartphone usage, the amount and the diversity of information have increased to amounts that are difficult to quantify. Within such an era of accelerated accumulation and diversification of digitalized information, the informatization of universities is becoming a critical factor for institutional advancement. Thus, universities are developing smartphone applications to provide easily accessible administration services, and support the information needs of each administration process by keeping a relationship with students from admission to post-graduation. This research systematically defines a university smartphone application, distinguishes its system quality factors, and studies the effects they have on satisfaction, intention of reuse, and intention of electronic word-of-mouth. The results showed that the security factor of system quality did not have a significant effect on satisfaction. The responsiveness and the empathy factors of service quality did not show a significant effect on satisfaction. Moreover, it was found that a higher user satisfaction for smartphone applications has a significant influence on intention of reuse and on the intention of electronic word-of-mouth.

• Structural Engineering and Mechanics
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• v.47 no.4
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• pp.545-557
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• 2013

Disposal of construction wastes poses major challenge to the municipal administration in the developing countries. At the same time new developments in these countries are unscrupulously exploiting the natural resources. The sustainable development requires judicious and careful utilization of natural resources. In this context, reuse of construction and demolition waste can save the global natural resources to greater extent. In this work the bricks and concrete waste from construction sites were crushed to the desired sizes and mixed in various proportions to study its properties in the concrete both in fresh and hardened states. Six mixes of natural and recycled aggregates were used to make the coarse aggregates for the concrete. From each mix nine cylinders were cast, which were tested at 7,14 and 28 days. The properties of concrete with recycled aggregates were compared with the control mix having natural aggregates. The nominal ratio of cement sand and coarse aggregates were kept at 1:2:4 by weight for all mixes. The tests have shown that concrete with recycled aggregates made from old concrete and brick bats provide greater opportunities for reuse of construction wastes in concrete.

• Journal of Technologic Dentistry
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• v.17 no.1
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• pp.10-25
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• 1995

The purpose of this study is to get the difference of the castability in the production of partial denture between Precious Metal Alloys and Base Metal Alloys accompanied with the frequency of reuse. As materials for an experiment, we selected Baker-444 and Soo-444 and Soo-sung as Precious Metal Alloys, New Crown and Chrome Cobalt as Base Metal Alloys. And we tired to case all of them seven times. The experimental results were as follows : 1) In the probability of segments, Baker-444 showed 100$\pm$0.00%, Soo-sung 97.24$\pm$1.58%, New Crown 95.63$\pm$4.28%, and Chrome Cobalt 91.03$\pm$7.76%. Consequently, Precious Metal Alloys were decidely superior to Base Metal Alloys in the castability. 2) In the view of the acheived result, burn-out temperature and smocking time had greatly affected the castability. 3) After casting, Precious Metal Alloys were much less than Base Metal Alloys in the quantity of consumption. It made much difference from the the compiled stastics(p<0.01)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.452-458
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• 2002

Although the reuse of the cached data for scrolling the map reduces the amount of passed data between client and server, it needs the conversions of data coordinates, selertive deletion of objects and cache compaction at client. The conversion is time intensive operation due to limited resources of mobile phones such as low computing power, small memory. Therefore, for the efficient map control in the vector map service based mobile phone, it is necessary to study the method for reducing wireless network bandwidth and for overwhelming the limited resources of mobile phone as well. This paper proposes the methods for racking pre-received spatial objects in client-server systems for mobile CIS. We also analyze the strengths and drawbacks between the reuse of cached data and transmission of raw data respectively.

• Transactions on Electrical and Electronic Materials
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• v.12 no.5
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• pp.175-188
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• 2011

As complementary metal-oxide semiconductor (CMOS) continues to scale down deeper into the nanoscale, various device non-idealities cause the I-V characteristics to be substantially different from well-tempered metal-oxide semiconductor field-effect transistors (MOSFETs). The last few years witnessed a dramatic increase in nanotechnology research, especially the nanoelectronics. These technologies vary in their maturity. Carbon nanotubes (CNTs) are at the forefront of these new materials because of the unique mechanical and electronic properties. CNTFET is the most promising technology to extend or complement traditional silicon technology due to three reasons: first, the operation principle and the device structure are similar to CMOS devices and it is possible to reuse the established CMOS design infrastructure. Second, it is also possible to reuse CMOS fabrication process. And the most important reason is that CNTFET has the best experimentally demonstrated device current carrying ability to date. This paper discusses and reviewsthe feasibility of the CNTFET's application at this point of time in integrated circuits design by investigating different types of circuit blocks considering the advantages that the CNTFETs offer.

• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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• pp.981-987
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• 2011

Biologically treated water contains a large quantity of organic matters and microorganisms which can cause various problems to membrane. The membrane fouling occurred by these reasons is hard to control by single physical cleaning. This study analyzes the efficiency of aeration with chemical backwashing and foulants removal during chemical backwashing. The cleaning efficiency improves when the chemical concentration is high and the contact time of chemical is long. Chemical backwashing with aeration shows exceptional cleaning efficiency which leads the physical cleaning is required during chemical backwashing since it forms flow inside the membrane submerged tank. From the foulants removal analysis, the particles such as turbidity and TOC removal rate increase when the aeration is applied. Dissolved matter of DOC and UV254 removal is dependent on higher chemical concentration. According to FTIR analysis, one of major foulants, the polysaccharide is controlled by the chemical backwashing with aeration condition.

• The Journal of Information Systems
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• v.17 no.4
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• pp.31-49
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• 2008

As the development of information technology, the biggest change in educational paradigm is apparent in the shift that the emphasis of education is layed on from teachers to learners. E-learning education service through the internet is less restricted in the respect of time and places in comparison with off-line education. Therefore e-Learning is spreaded rapidly and the educational effectiveness of that is needed to be investigated. In this study theoretical research was performed firstly and framework of the study was constructed. After establishment of hypotheses the survey data were collected by the learners of e-Learning and the hypotheses were verified by the SPSS version 12.0. The results are as follows : First, the quality of e-Learning service influences significantly to the technology acceptance of users. Secondly, perceived usability and perceived easiness of technology acceptance model influences significantly to the intention of reuse of users of e-Learning services. Lastly, the playfulness of the Flow theory influences significantly to the intention of reuse of users of e-Learning services. Although there are some limitations in the respect of the numbers of variables, parameters, or samples, this study will contribute for enhancing the effectiveness of education in e-Learning service by providing the acceptance factors of e-learners.