• Steel and Composite Structures
• /
• v.35 no.5
• /
• pp.635-640
• /
• 2020

The buckling analysis of the embedded sinusoidal piezoelectric beam is evaluated using numerical method. The smart beam is subjected to external voltage in the thickness direction. Elastic medium is simulated with two parameters of spring and shear. The structure is modelled by sinusoidal shear deformation theory (SSDT) and utilizing energy method, the final governing equations are derived on the basis of piezo-elasticity theory. In order to obtaining the buckling load, the differential quadrature method (DQM) is used. The obtained results are validated with other published works. The effects of beam length and thickness, elastic medium, boundary condition and external voltage are shown on the buckling load of the structure. Numerical results show that with enhancing the beam length, the buckling load is decreased. In addition, applying negative voltage, improves the buckling load of the smart beam.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.27 no.4
• /
• pp.885-895
• /
• 2017

Security issues arise due to various types of external intrusions as much as the rapidly changing IT environment. Attacks using vulnerabilities in web applications are increasing, and companies are trying to find the cause of the vulnerability, prevent external intrusion, and protect their systems and important information. Especially, according to the Supervision Regulation, each financial institution and electronic financial service provider shall perform vulnerability analysis evaluation for the website for disclosure once every six months and report the result to the Financial Services Commission. In this study, based on the Web vulnerability items defined in the Supervision Regulation, based on the inspection cases of actual financial institution, we analyze the most frequently occurring items and propose effective countermeasures against them and ways to prevent them from occurring in advance.

• Journal of Information Technology Applications and Management
• /
• v.17 no.1
• /
• pp.11-33
• /
• 2010

The majority of graphs and visuals made publicly available by Thai listed companies tend to be disjointed and minimal. Only a little over fifty percent of the total 478 companies included graphic representations of their business operations and performance in the form of two or three dimensional spreadsheet based graphs in their annual reports, investor relations documents, websites and so on. For novice users, these visual representations are unlikely to give the big picture of what is the company's financial position and performance. Neither will they tell where the company stands in its own operating environment. The existing graphics and visuals, in very rare cases, can provide a sense of the company's future outlook. For boundary users such as audit committees whose duty is to promote good governance through transparency and disclosure, preliminary interview results show that there is some doubt as to whether the inclusion of big-picture visuals can really be of use to minority shareholders. These boundary users expect to see more insightful visuals beyond those produced by traditional spreadsheets which will enable them to learn to cope with the on-going turbulence in today's business environment more quickly. However, the debate is still going on as to where to draw the line between internal or external reporting visuals.

• Journal of Magnetics
• /
• v.1 no.2
• /
• pp.64-68
• /
• 1996

Compared with the conventional magnetostriction in Ni alloys which are in the order of several tens ppm (Parts Per Million =10-6), RFe$_2$(R = rare earth element) Laves Phase intermetallic compounds show large saturation magnetostriction in the range of a few thousands ppm. However, the large external magnetic field necessary to obtain saturatio magnetostriction has due to large magnetocrystalline anisotropy energy restrained the applicationof magnetostriction materials in RFe$_2$intermetallic compounds. As a result of its solution, the largest published value of effective giant magnetostriction in a low external magnetic field (less than a few hundred Oe) is reported in this paper by means of amorphisation of RFe$_2$intermetallic compounds with the addition of boron, as a half metal. For the amorphous (SmFe$_2$)0.97 B0.03 alloys, the effective magnetostriction of -545 and -610 $\times$ 10-6 is obtained at 400 and 1,000 Ie, respectively. Moreover, the effective magnetostriction of 590 and 630$\times$10-6 in the amorphous (TbFe$_2$)0.98 B0.02 alloys is also found at 400 and 1,000 Oe, respectively. This result will provide a clue to understanding the effect of half metal on anomalous increase of the effective giant magnetostriction and attract the great attention for magnetostriction applications.

• Journal of Magnetics
• /
• v.19 no.4
• /
• pp.345-348
• /
• 2014

Magnetorheological suspensions (MRSs) are smart materials that have the potential to revolutionize several industrial sectors because of their special rheological behaviors. In this paper, MRS, based on carbonyl iron (CI) microparticles that were dispersed in silicone oil with oleic acid, were prepared. We showed that the electroconductibility of MRS was significantly influenced by the intensity of the external magnetic field that was applied. The resistance value can vary from infinite to below $300{\Omega}$ after applying an external magnetic field. The results indicated that this MRS had the property of magnetic-field-tuned insulator to conductor transition. This system has potential applications in controllable MRS electrical devices.

• International Commerce and Information Review
• /
• v.7 no.2
• /
• pp.75-94
• /
• 2005

This study is focused on evaluating the computer-integrated just-in-time (CI-JIT) production system of a semi-conductor manufacturing firm in Korea. Approaching the mid-1980s, the emphasis was on low price, low-cost operations, and quality, especially in USA. American companies have shifted output to low-wage countries like the Philippines, Korea, Japan, Malaysia and allied countries that can make quality products at low prices. Korea and other Asian countries forego short-term profits to gain a solid foothold in a product market, recognizing that larger market share leads to lower cost and higher profit in the long run. They bring manufacturers and suppliers together to improve material management and operation management, using project teams that investigate topics, such as Just-In-Time(JIT)manufacturing, among others. The "Kanban" word means "card" in Japanese, and is used to indicate the desired final delivery schedule. The operation for a particular item produced is scheduled for a specific time. The same process is extended to the external suppliers. More recently, the cards are gradually being replaced by electronic procedures that follow the same concept. Its capacity must be capable of handling the various transactions required by the JIT coverage as well as some allowances for expanded applications.

• The Journal of Pediatrics of Korean Medicine
• /
• v.26 no.2
• /
• pp.53-61
• /
• 2012

Objectives To make comprehensive feature of clinical trials using herbal medicine and their results by today, then help a strategy for herbal medication-derived clinical studies in the future. Methods Through medical website (Pubmed EBSCO Medline), foreign clinical literatures about atopic dermatitis and herbal medicine were searched. And domestic clinical literatures about atopic dermatitis using internet website (OASIS) and hand-searching. Analysis was performed according to distribution mainly by subject, study design, number by year and its efficacy. Results and Conclusions Seventy-nine (Domestic literatures: Fifty, Foreign literatures: Twenty-nine) literatures were selected according to inclusion criteria of clinical study. 80% of domestic clinical literatures were observational studies, 50% of foreign were intervention. There were six adverse effect case studies, two follow-ups, one case report, four translational and four uncontrolled clinical trials in foreign literatures. And nineteen case reports, eighteen case series, two follow-up and five uncontrolled clinical studies in domestic. Six RCTs have established by four external herb therapy and two decoctions in Korea, showed positive effects. Three out of four external applications RCTs, four out of seven decoctions showed positive results in foreign studies. This study revealed the current status of atopic dermatitis clinical research using herbal drugs. To put clinical trials to use of herbal medicine in the treatment atopic dermatitis, scientific and objective-based studies should be needed.

• Journal of Aerospace System Engineering
• /
• v.11 no.1
• /
• pp.22-27
• /
• 2017

In this paper, a walking vibration sensing system (WVS system) using a Fiber Bragg Grating sensor (FBG sensor) is proposed. The seismic part of the FBG sensor was redesigned for sensitivity enhancement. The external excitation was assumed to be the walking cycle of an adult male. The FBG seismic sensor was redesigned using CATIA and ABAQUS such that the sensor's first mode natural frequency is 3.5 Hz (which is a value near the external excitation frequency). Compared with existing walking vibration sensing systems, this newly created system improves sensitivity 15 times. It is also suitable for intrusion detection applications.

• Progress in Superconductivity and Cryogenics
• /
• v.21 no.4
• /
• pp.48-52
• /
• 2019

Recently, many studies have been reported on the magnetoresistance and Hall effect of REBCO thin films and bulk. The voltage interferes quench detection of high-temperature superconducting magnet and generates leakage current in no insulation high-temperature superconducting coil. Therefore, in this paper, experiments on magnetoresistance and Hall effect of commercial YBCO and GdBCO tapes have been carried out. As a result, anomalous voltages expected for the magnetoresistance and Hall effect of REBCO tapes were observed and analyzed. In addition, the voltage characteristics of REBCO have been identified, and the Hall coefficient are calculated for use in high magnetic field magnet applications.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.4
• /
• pp.245-252
• /
• 2016

Girth gears are applied in the mining, cement, and mineral processing industries and used in various types of horizontal mills, rotary dryers and kilns, and other heavy-gear ring applications. The large ring gears are normally fitted outside mills or kilns to provide the primary rotational drive. Recently, an external pinwheel gear set (e-PGS) was introduced to overcome manufacturing problems associated with girth gears. e-PGS is also suitable for low-speed, heavy-duty mechanical transmission and dusty and poor-lubrication conditions. This paper first presents a new profile modification of root relief for the e-PGS cam pinion. We then investigate load-stress factors to estimate the surface fatigue life by varying the shape design parameters. The results show that the contact fatigue life of an e-PGS can be extended significantly by increasing the profile shift coefficient. However, support bearing life of the pinwheel depends more on the contact force distribution than the profile shift coefficient.