• The Transactions of the Korea Information Processing Society
• /
• v.5 no.10
• /
• pp.2556-2566
• /
• 1998

Program slicing is a technique to extract the statements which influence the value of a variable at a particular point of the program. It has been proposed that this technique is useful in debugging, iptimization, program maintenance, testing, extraction reusable components and other applications including the understanding of the program behavior. This paper aims to address the problem of slicing programs with Jump goto, break, continue in C statements, It was found that previous slicing algorithms do not always generate semantically correct slices when applied to such programs. We, therefore, point out why the previous methods do not work in this more general setting, and describe our eficient solutions that compate more correctly executable slices for such programs.

• Macromolecular Research
• /
• v.13 no.2
• /
• pp.81-87
• /
• 2005

Blends of silicone rubber (VMQ) and liquid crystalline polymer (LCP) were prepared by the melt mixing technique. Mechanical, XRD, thermal and dynamic mechanical investigations are reported for the pure silicone rubber and blends. The mechanical properties, viz. the tensile strength, tear strength and elongation at break, of the silicone rubber decreased with the addition of LCP. The SEM study on the tensile fractured surface of the blends revealed that they had a two phase structure, and that the failure was mainly due to fiber pull out, which suggests that the VMQ and LCP are incompatible in all of the proportions examined in this study. However, the FTIR study shows that there was a partial interaction between the VMQ and LCP, but which may not be sufficient to grip the fibrils under the applied load. In the XRD analysis, it was observed that the crystalline structure of the silicone rubber deteriorated in the presence of LCP. The DMA study suggested that the storage modulus of the silicone rubber was improved with the addition of LCP, due to the high modulus of the LCP phase. The thermal stability of the silicone rubber was greatly reduced by the addition of LCP, due to the latter having a thermal stability lower than that of silicone rubber.

• Journal of Korean Society of Water and Wastewater
• /
• v.23 no.3
• /
• pp.339-344
• /
• 2009

The authors investigated the bacterial community attached to granular activated carbon(GAC) particles and the susceptibility of the community to chlorine disinfection. The study was carried out at the G Water Treatment Plant in Seoul, which was in full-scale operation. Bacteria attached to the surface of GAC increased gradually with treatment from $0.4{\times}106{\sim}8.5{\times}106 CFU/g$. TOC removal was under 1.0 mg/L due to increased bacterial community on the surface of GAC. It was found that TOC removal was closely related with physical and biological parameters such as pore volume and the number of attached bacteria. When the washed and the attached cells were disinfected with 1.0mg/L of chlorine for 1 hour, the washed cells with chlorination could be controlled, but the number of the attached cells increased gradually. The results suggest a possibility that the treatment and disinfection barriers can be penetrated and pathogenic bacteria may break into the drinking water supplying system.

• Journal of Korea Water Resources Association
• /
• v.34 no.6
• /
• pp.605-615
• /
• 2001

SMAC method, one of the numerical simulation techniques, is modified from the original MAC method for the time-dependent variation of fluid flows. The Navier-Stokes equations for incompressible time-dependent viscous flow is applied, and marker particles which present the visualization of fluid flaws are used. In this study, two-dimensional numerical simulations of the water column collapse are carried out by SMAC method, and the simulation results are compared with Martin and Moyce's experimental data and result of the MPS method. A good results are obtained. This numerical simulation could also be applied to the breaking phenomenon of hydraulic structures such as dam break.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2008.05a
• /
• pp.624-628
• /
• 2008

Two-dimensional flow analysis is a way to provide good estimates for complex flow features in flow around islands and obstructions, flow at confluence and flow in braided channel. One of difficult problems to develop a two-dimensional hydraulic model is to analyze dry and wet area in river channel. Dry/wet problem can be encountered in river and coastal engineering problems, such as flood propagation, dam break analysis, tidal processes and so on. The objective of this study is to develop an accurate and robust two-dimensional finite element method with dry/wet technique in complex natural rivers. The dry/wet technique with Deforming Grid Method was developed in this study. The Deforming Grid Method was used to construct new mesh by eliminating of dry nodes and elements. The eliminated nodes and elements were decided by considering of the rising/descending velocity of water surface elevation. Several numerical simulations were carried out to examine the performance of the Deforming Grid Method for the purpose of validation and verification of the model in rectangular and trapezoidal channel with partly dry side. The application results of the model were displayed reasonable flow distribution.

• The Journal of Information Systems
• /
• v.13 no.2
• /
• pp.1-22
• /
• 2004

Internet commerce has the potential to propel a company to "break out" of existing strategic constraints and radically alter business processes, strengthen customer and supplier ties, and open up new markets. Therefore, many firms have rushed into internet commerce to conduct business more efficiently, create new business opportunities, and generate business value. Since internet shopping mall not only become a valuable channel for selling goods to customers, but also offer companies an important vehicle for attaining competitive advantages in the new digital economy, the design and content of internet shopping mall must reflect its business goals and customers' needs. However, as little empirical evidence on the effect of internet shopping mall contribution of firm performance exist, the functionality of a firm's internet shopping mall has been decided voluntarily from its business experience. The purpose of this study is to examine the relationship between the marketing functional characteristics of internet shopping mall and its performance. 125 questionnaires from internet shopping malls which sell physical goods direct to an individual end consumer were collected. The results showed that some factors(price, product recognition, reliability enhancement) affect positive effects on the performance of internet shopping mall.

• Journal of Acupuncture Research
• /
• v.15 no.2
• /
• pp.437-454
• /
• 1998

Osteopotosis is a disease characterized by reduced amount of bone mass leading to enhanced bone flagility. The number of patients with osteoporotic vertebral fracture is increasing and it is one of the leading causes of morbidity in the elderly and postmenopausal women. It is a condition in which bone mass decrease, causing bones to be more susceptible to fracture. A trivial trauma can easily cause one or more bones to break in a person with severe osteoporosis. So it is a major health problem. Pysicians and patients are concerned with the optimum approach to the treatment and prevention of osteoporosis. Until a recent date, many oriental medicine studies were performed to find the preventive and curative efficacy on the osteoporosis, which is differ from therapeutics of Western-medicine. The proper use of Herb-med and role of Accupuncture are issues that have generated major research efforts. This study was carried out to investigate evaluation of clinical and experimental study on the osteoporosis. So, these are to be mentioned in this paper.

• Carbon letters
• /
• v.9 no.2
• /
• pp.115-120
• /
• 2008

Rubber reinforcing carbon black N330 was treated by physical activation under $CO_2$ to different degrees of burn-off. The mechanical properties indicating the reinforcement of SBR (Styrene-Butadiene Rubber) vulcanizates filled by activated carbon blacks, such as tensile strength, modulus at 300% strain and elongation at break were determined. During $CO_2$ activation of fresh carbon blacks, the development of microporous structure caused an increase of extremely large specific surface area and the porosity turned out to be an increasing function of the degree of burn-off. The tensile strength and modulus at 300% of activated carbon blacks filled rubber composites were improved at lower loading ratios of 20 and 30 phr, but decreased drastically after 30 phr, which is considered that it might be difficult to get a fully dispersed rubber mixture at higher loading ratios for fillers having very large specific surface areas. However, the Electromagnetic Interference (EMI) shielding effectiveness of SBR rubber composites having activated carbon black at 74% yield were improved at a large extent when compared to those having raw carbon black and increased significantly as a function of increasing loading ratio.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.13 no.2
• /
• pp.160-170
• /
• 1988

This paper describes the outboard NIU(Network Interface Unit) using microprocessor and the hardware and software of concentrator for constructing star typed LAN(Local Area Network) based on token ring method. The NIU adapter can adapter up to four parallel and serial typed terminals. Because it has PAD function on input output data, any type of terminals can be adapted. Since the concentrator has logical switching circuit which enables data to bypass the faulted NIU adapter, this network prevents communication break. When user transmits and receives data, the concentrator constructs star typed LAN which connct both transmitting and receiving sides. A s result, this network eliminated ring latency time in other NIU exculding transmitting and receiving NIU. So the throughput of this LAN is increased. Because this LAN system consists of several modultes according to it's function, the expansion of function or the modification of method is easy.

• The Bulletin of The Korean Astronomical Society
• /
• v.37 no.1
• /
• pp.101.2-101.2
• /
• 2012

An asteroid family is a population of asteroids in the proper orbital element space (a, e, i), considered to have been produced by a disruption of a large parent body presumably through a catastrophic collision. Asteroid families offer unique opportunities to reconstruct and characterize the break-up history of airless bodies in the main-belt. The Maria family is a typical old population (~3${\pm}$1 Gyr) of asteroids that have undergone significant collisional and dynamical evolution in the history of the inner Solar System; it is also believed to be one of the candidate source regions for giant S-type near-earth asteroids (NEAs). However, to date, physical characteristics of this family members such as rotational periods have been known only for 61 of the larger asteroids among 3,230 objects, which accounts for less than 2 percent of the family. In this presentation, we provide some preliminary results of our recent study: out of more than dozen of the family members, lightcurves for eight objects have been obtained for the first time. We plan to increase the number of target objects, and investigate evidences for the Yarkovsky/YORP effect on Maria family based on our observations.