• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.37-46
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• 2007

In wireless sensor networks, one of the most important goals of designing protocols is to extend the network lifetime. A node has lots of duplication in sensing and communication range with surrounding nodes after many of nodes are randomly scattered. Such a heavy duplication overhead affects on the network lifetime seriously so usually all nodes need not activated constantly to carry out sensing and communication operation. One of the optimal methods of prolonging the network lifetime is finding the number of surrounding nodes necessary to maintain the network coverage and connectivity. It has been studied till the current date in wireless networks. If the neighbor necessary can be acquired to satisfy the probability using the ideal number of neighbors necessary and the acquired number of neighbors m to guarantee network coverage and connectivity. We use the result that F. Xue et al and S. Song et al derive previously in finding the neighbor necessary to guarantee the network connectivity and cany out the computer simulation to verify the necessary number. We present that our scheme satisfy the network coverage and connectivity. We present the simulation results compared with constant probability scheme through computer simulation.

• 대한공업교육학회지
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• v.33 no.2
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• pp.287-299
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• 2008

HTTP is one of the most widely used protocols of the WWW. Currently it uses TCP as the transport layer protocol to provide reliability. The HTTP uses separate TCP connection for each file request and adds unnecessary head-of-line blocking overhead for the file retrieval. The web application is short sized and affected by the increased handover latency of TCP in wireless environment. SCTP has attractive features such as multi-streaming and multi-homing. SCTP's multi-streaming and multi-homing avoid head-of-line blocking problem of TCP and reduce handover latency of TCP in wired and wireless environment. Mean response time is the important measure in most web application. In this paper, we present the comparison of mean response time between HTTP over SCTP with that of HTTP over TCP in wired and wireless environments using NS-2 simulator. We measured mean response time for varying packet loss rate, bandwidth, RTT, and the number of web objects in wired environment and mean response time and packet loss rate for varying moving speed and region size in wireless environment. Our experimental result shows that SCTP reduces the mean response time of TCP based web traffic.

• Progress in Medical Physics
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• v.16 no.2
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• pp.53-61
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• 2005

The quality factors for cylindrical ionization chambers for kV X-rays were determined by Monte Carlo calculation and measurement. In this study, the X-rays of 60-300 kV beam (lSO-4037) installed in KFDA and specified in energy spectra and beam qualities, and the chambers of PTW N23333 and N30001 were investigated. In calculations, the $R_{\mu}\;and\;R_{Q,Q_{0}}$ in IAEA dosimetry protocols were determined from the air kerma and the cavity dose obtained by theoretical and Monte Carlo calculations. It is shown that the N30001 chamber has a flat response of $\pm1.7\%$ in $110\~300kV$ region, while the response range of two chambers were shown to $\pm3\~4\%$ in $80\~250kV$ region. From this work we have discussed dosimetry protocol for the kV X-rays and we have found that the estimation of energy dependency is more important to apply dosimetry protocol for kV X-rays.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.1
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• pp.115-125
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• 2011

Cryptographic hash functions are also called one-way functions and they ensure the integrity of communication data and command by detecting or blocking forgery. Also hash functions can be used with other security protocols for signature, authentication, and key distribution. The SHA-1 was widely used until it was found to be cryptographically broken by Wang, et. al, 2005. For this reason, NIST launched the SHA-3 competition in November 2007 to develop new secure hash function by 2012. Many SHA-3 hash functions were proposed and currently in review process. To choose new SHA-3 hash function among the proposed hash functions, there have been many efforts to analyze the cryptographic secureness, hardware/software characteristics on each proposed one. However there are few research efforts on the SHA-3 from the point of power consumption, which is a crucial metric on hardware module. In this paper, we analyze the power consumption characteristics of the SHA-3 hash functions when they are made in the form of ASIC hardware module. Also we propose power efficient hardware architecture on Luffa, which is strong candidate as a new SHA-3 hash function. Our proposed low power architecture for Luffa achieves 10% less power consumption than previous Luffa hardware architecture.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.470-484
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• 2020

An earthquake of magnitude 5.4 occurred on November 15, 2017 in Pohang, which caused the damage to buildings and facilities. The earthquake displaced more than 1,700 people. After the Pohang Earthquake, immediate emergency, such as the damage survey and running of shelters have been executed appropriately. However there have been issues with subsequent restoration measures, such as the provision of temporary housing and delivery of natural disaster allowance. As there was inadequate government advertisement about the natural disaster allowance, victims of the earthquake could not receive tangible help. In Japan on the other hand where earthquakes are frequent, post-earthquake restoration protocols are planned well in advance. For example, Japanese earthquake victims are provided with a guidebook outlining different types of government aids available for them so that they can rapidly access government aid. In this study, we refer to the case of Pohang earthquake to analyse the problems in the national earthquake restoration plans and propose how they can be improved by comparing it to Japanese post-earthquake case and a Korean equivalent should be developed, to aid Korean earthquake victims to return to their every life as soon as possible.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1994-2005
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• 2015

Voice over IP (VoIP) is a technology for the delivery of voice communications and multimedia sessions over Internet Protocol (IP) networks. Instead of being transmitted over a circuit-switched network, however, the digital information is packetized, and transmission occurs in the form of IP packets over a packet-switched network which consist of several layers of computers. VoIP Service that used the various techniques has many advantages such as a voice Service, multimedia and additional service with cheap cost and so on. But the various frauds arises using VoIP because VoIP has the existing vulnerabilities at the Internet and based on complex technologies, which in turn, involve different components, protocols, and interfaces. According to research results, during in 2012, 46 % of fraud calls being made in VoIP. The revenue loss is considerable by fraud call. Among we will analyze for Toll Bypass Fraud by the SIM Box that occurs mainly on the international call, and propose the measures that can detect. Typically, proposed solutions to detect Toll Bypass fraud used DPI(Deep Packet Inspection) based on a variety of detection methods that using the Signature or statistical information, but Fraudster has used a number of countermeasures to avoid it as well. Particularly a Fraudster used countermeasure that encrypt VoIP Call Setup/Termination of SIP Signal or voice and both. This paper proposes the solution that is identifying equipment of Toll Bypass fraud using those countermeasures. Through feature of Voice traffic analysis, to detect involved equipment, and those behavior analysis to identifying SIM Box or Service Sever of VoIP Service Providers.

• 모자간호학회지
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• v.4 no.1
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• pp.3-11
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• 1994

Presently there is an increasing demand for home health care services due to changes in the demographic structure as a result of an increasing elderly population, socio-economic improvements, and changes in the family structure, as well as the growing number of people with degenerative diseases. In addition to these reasons, rising medical costs and there a shortage of patient beds space in the hospital, particularly since introduction of national medical insurance. There has been an increasing demand for health care health care services. This study was done to identify the basic data for home health care management. It focused on developing client selection criteria, assessment tools, and recording methods. This was accomplished by the researchers visiting the patients in their homes. The research process included preparation investigation, tool development, training of the project researcher, and visiting the clients in their homes. The research tools are as follows : 1. Record development : a) The selection criteria tool for home health care of postpartum women was a structured tool and consisted of four parts. b) The structured assessment tool consisted of a general items, obstetric history, past medical history, methods of feeding, medications taken before admission, laboratory test results, discharge instructions, discharge medications, family tree, economic status, environmental status, a map, health assessment of postpartum women and their newborns. c) The visit note I consisted of the frequency of visits. Visit note II consisted of the date ; nursing problems ; nursing process including the initial assessment ; nursing goal ; visit plan ; postpartum women and their neonate health status, diagnosis, goal, implementation, evaluation, summary, next plan, for visit revision. d) Problem note consisted of the date, problem numbers, nursing diagnosis, problem appearance date problem resolution date. The research results are as follows : 1. Nursing problems : The nursing problems of the postpartum women and their neonates were evaluated by the number of nursing diagnoses and the change in the pattern of nursing diagnosis related to the number of visits. a) Nursing diagnosis The nursing diagnosis was classified according to physical function, psychosocial function, family system maintained function. b) The changes of nursing diagnosis related to the number of visits. As the type of nursing diagnosis changed related to the number of visits the number of nursing diagnoses decreased. 2. Contents of home health care : The content was categorized according to assessment, direct care, counseling, education, family care, reporting to with the attending doctor. The recommendations based on the research results are as follows : 1. Tool development Replication of this study is needed to test the validity of the assessment tools used. 2. Home visit a) Home health care nurses should be licensed and qualified. A referral form from the attending doctor is needed for legal protection of nurses. b) The first home visit need to be within 24 hours of discharge from the hospital to decrease the anxiety of frightened postpartum women. c) When the changes occur in the newborn's status, home health care nurses should consult a pediatrician. Communication within the home healthcare team is essential and needs to consistent and done smoothly. 3. Home health care A Study is required to develop protocols for education of staff and for operation of all aspects of this program.

• The Korea Journal of Herbology
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• v.25 no.2
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• pp.129-136
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• 2010

Objective : Sinapis alba L. (SA) is a korean traditional herbal medicine that is usually used to prevent or treat inflammatory diseases, such as respiratory infection and rheumatoid arthritis. However, the effects of SA supplementation in vitro on serum antibody levels, splenocyte and peritoneal macrophage immune responses have not yet been determined. In this study, we examined the effect of SA on the production of Th1/Th2 cytokines. Methods : Splenocytes were isolated from naive C57BL/6 mice. Cells were enriched for CD4+ cell populations by first staining the cells with anti-CD4 (BD PharMingen, Calif, USA). CD4+ T cells were selected on a (CS) column, and the flow-through was collected as CD4+ T cells. Isolated cells were activated by overnight incubation on 24-well plates coated with $1{\mu}g/mL$ anti-CD3, $1{\mu}g/mL$ anti-CD28 and with SA ($100{\mu}g/mL$). Primary macrophages were collected from the peritoneal cavities of mice (8-week-old female C57BL/6). The peritoneal macrophages were washed and plated with RPMI-1640 overnight for the experiments. After 48-hours cultures, samples were centrifuged at 2000 rpm for 10 minutes, and the supernatants were stored at $-80^{\circ}C$. Mouse IL-4, IFN-$\gamma$ and TNF-$\alpha$ were quantified using ELISA kits (BioSource International, Camarillo, Calif, USA) according to the manufacturer's protocols. Results : SA at 100ug/ml decreased the generation of Th1 cytokine (IFN-$\gamma$) by 0.5-fold. However, SA has no effect on Th2 (IL-4) production. Conclusions : These results suggest that SA may play an important role in the control of T-cell-mediated autoimmunity by down-regulation of Th1 cytokine (especially IFN-$\gamma$, TNF-$\alpha$). These data may contribute to the design of new immunomodulating treatments for a group of autoimmune diseases.

• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.119-124
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• 2002

This study was carried out to investigate the effects of packing materials of frozen boar semen to improve reproductive performance efficiency in pig. Boars were raised at Swine Artificial Insemination Center in National Livestock Research Institute, Sunghwan, Chungnam, Korea. We compared packing protocols for frozen boar semen among 5$m\ell$ maxi-straw, 5$m\ell$ cryogenic-vial, and aluminum-pack. Cryogenic-vial packing material showed similar sperm characteristics compared with maxi-straw packing material when the sperm was frozen above 15cm from liquid nitrogen and thawed at 52$^{\circ}C$ for 190 seconds. We investigated different thawing times to find out the optimal condition of freezing and thawing protocol with cryogenic-vial. Freezing above 15cm from liquid nitrogen and thawing at 52$^{\circ}C$ for 190 seconds were the optimal protocol compared with 120 and 150 seconds. However, normal acrosome rates did not show any differences among thawing times. Post-thawing results of maxi-straw in water at 52$^{\circ}C$ for 45 seconds had better total motility and curve linear velocity than those of cryogenic-vial in water 52$^{\circ}C$ for 190 seconds. However, there were no differences on straightness and normal apical ridge of sperm between maxi-straw and cryogenic vial. Non-return rate, farrowing rate and litter size of sows inseminated with frozen boar semen of commercial farms were higher in the maxi-straw than cryogenic-vial, but there were no significant differences between maxi-straw and cryogenic-vial. In conclusion, there were no significant differences between maxi-straw and cryogenic-vial and so, we may replace cryogenic-vial packing method instead of maxi-straw packing method by improvement of freezing and thawing rate.

• Toxicological Research
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• v.30 no.4
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• pp.305-309
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• 2014

Recently, there has been an increase in the use of several nephrotoxicity biomarkers in preclinical experiments. In addition, it has been indicated that the result may have been influenced by secondary factors, such as sample storage condition or storage period. In this study, we have assessed the variation in urinary nephrotoxicity biomarkers as a result of urine storage conditions and storage period of the urine. Urine was sampled from specific pathogen-free Sprague-Dawley rats (19 weeks old), which were housed individually in hanged stainless steel wire mesh cages. Urine was stored at $20^{\circ}C$, at $4^{\circ}C$, or at $-70^{\circ}C$ after sampling. The levels of the biomarkers such as beta-2 microglobulin (B2M), cystatin-C (Cys-C), N-acetyl-${\beta}$-D-glucosaminidase (NAG), micro albumin (MA), micro protein (MP) were measured at 6, 24, 48 and 144 hr after sampling. The B2M level was significantly decreased at 6, 24, 48, and 144 hr compared to 0 hr at $-70^{\circ}C$ (p < 0.05, p < 0.01, p < 0.05, and p < 0.05, respectively) and 24 and 144 hr at $20^{\circ}C$ (p < 0.01, p < 0.01, respectively). The Cys-C level was significantly decreased at 144 hr compared to 0 hr at $4^{\circ}C$ (p < 0.01), at $20^{\circ}C$ (p < 0.05) and at $70^{\circ}C$ (p < 0.01). MP and MA levels were not different for 144 hr in all storage conditions. Taken together, B2M and Cys-C levels were modulated by storage temperature and period. For the enhancement of test accuracy, it is suggested that strict protocols be established for samples to minimize the effects of the storage conditions on the detected levels of biomarkers.