• Journal of Multimedia Information System
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• v.6 no.2
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• pp.61-66
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• 2019

VANET (Vehicular Ad-hoc Network) is a mobile Ad-hoc Network which deals with the moving vehicles. VANET supports Intelligent Transport Systems (ITS) which is related to different modes of transport and traffic management techniques. VANETs enabled users to be informed and make them safer. VANET uses IEEE 802.11p standard wireless access protocol for communication. An important and necessary issue of VANET is to design routing protocols. In a network, communication takes place by the use of the routing protocols. There are mainly two types of communications used such as Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) in VANET. Vehicles can send and receive messages among them and also to and from infrastructure used. In this paper, AODV, DSR and DSDV are compared by analysing the results of simulation on various metrics such as average throughput, instant throughput, packet delivery ratio and residual energy. Findings indicates utilization of AODV and DSR is more applicable for these metrics as compared to DSDV. A network simulator (NS2) is used for simulation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.2
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• pp.208-213
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• 2003

Recently, a variety of new routing protocols targeted specifically wireless mobile nodes environment have been developed. This paper presents the results of a detailed packet level simulation comparing two multi-hop wireless ad-hoc network routing protocols that cover a range of design choices between DSDV and DSR. And we suggest a performance comparison of network routing protocols through NS-2 simulator.

• Journal of Communications and Networks
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• v.6 no.2
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• pp.156-162
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• 2004

In recent years, mobile ad-hoc networks have received a great deal of attention in both academia and industry to provide anytime-anywhere networking services. As wireless networks are rapidly deployed, the security of wireless environment will be mandatory. In this paper, we describe a group key management architecture and key agreement protocols for secure communication in mobile ad-hoc wireless networks (MANETs) overseen by unmanned aerial vehicles (UAVs). We use implicitly certified public keys method, which alleviates the certificate overhead and improves computational efficiency. The architecture uses a two-layered key management approach where the group of nodes is divided into: 1) Cell groups consisting of ground nodes and 2) control groups consisting of cell group managers. The chief benefit of this approach is that the effects of a membership change are restricted to the single cell group.

• Journal of Preventive Medicine and Public Health
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• v.49 no.2
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• pp.134-138
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• 2016

Objectives: Season of birth, an exogenous indicator of early life environment, has been related to higher risk of adverse psychiatric outcomes but the findings for Alzheimer's disease (AD) have been inconsistent. We investigated whether the month or season of birth are associated with AD. Methods: A nationwide nested case-control study including all community-dwellers with clinically verified AD diagnosed in 2005 to 2012 (n=70 719) and up to four age- sex- and region of residence-matched controls (n=282 862) residing in Finland. Associations between month and season of birth and AD were studied with conditional logistic regression. Results: Month of birth was not associated with AD (p=0.09). No strong associations were observed with season (p=0.13), although in comparison to winter births (December-February) summer births (June-August) were associated with higher odds of AD (odds ratio, 1.03; 95% confidence interval, 1.00 to 1.05). However, the absolute difference in prevalence in winter births was only 0.5% (prevalence of those born in winter were 31.7% and 32.2% for cases and controls, respectively). Conclusions: Although our findings do not support the hypothesis that season of birth is related to AD/dementia risk, they do not invalidate the developmental origins of health and disease hypothesis in late-life cognition. It is possible that season does not adequately capture the early life circumstances, or that other (postnatal) risk factors such as lifestyle or socioeconomic factors overrule the impact of prenatal and perinatal factors.

• Journal of KIISE:Information Networking
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• v.31 no.1
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• pp.62-69
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• 2004

The cluster structure reduces the number of retransmission messages, when a broadcast to all hosts in ad hoc network is needed. A cluster maintenance scheme is employed to preserve this advantage from time to time. However, most of the cluster maintenance schemes require additional control messages for cluster reformation as well as control messages for acquiring neighbor information. This mitigates the advantages of employing cluster structure in ad hoc network. In this paper, a cluster maintenance scheme which forces only clusterheads to broadcast control messages during hello time is proposed. When the cluster reformation is needed, the proposed scheme employs a strategy to reduce the control messages to a minimum. In these processes, the proposed scheme doesn't violate the definition of 2-cluster and produces the clusters in fully distributed method. The simulation results prove that our scheme is better than LCC(1).

• Journal of Haehwa Medicine
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• v.14 no.2
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• pp.113-126
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• 2005

Atopic dermatitis(AD) is a chronic disease that affects the skin. "Atopic" refers to a group of diseases where there is often an inherited tendency to develop other allergic conditions, such as asthma and hay fever. In AD, symptoms vary from person to person. The most common symptoms are dry, itchy skin and rashes on the face, inside the elbows and behind the knees, and on the hands and feet. Although AD may occur at any age, it most often begins in infancy and childhood. The cause of AD is not known, but the disease seems to result from a combination of hereditary and environmental factors along with malfunction of the body's immune system. In contrast to that, the results from literatual study in oriental medicine are as follows; 1. The causes of AD are considered to be Mosusigisadok(母受時氣毒), Waegampoongsubyeol(外感風濕熱), Guasiksinlayeolmul(過食辛辣熱物), Ohbokonje(誤服溫劑). 2. The symptoms are fever, flushed face, red eyes, oliguria, constipation and itching. 3. Chungyeolhaedok(淸熱解毒) would be the basic method of treatment, and it divides into two categories; Subhyung(濕型) and Gunhyung(乾型). In Subhyung(濕型), AD is treated by Josub(燥濕), Chungyeol(淸熱) and Jiyang(止痒) whereas Chungyeol(淸熱), Jiyang(止痒), Jesub(除濕) in Gunhyung(乾型). 4. To prevent further damage and enhance quality of life, it is necessary to keep the temperature and humidity favorable, and healing the skin and keeping it healthy are important. Developing and sticking with a daily skin care routine is critical to preventing flares. Changing the diet and psychological stability may also be helpful to relieve symptoms of AD.

• Advances in pediatric surgery
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• v.11 no.1
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• pp.27-33
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• 2005

Infantile hypertrophic pyloric stenosis (HPS) is a relatively common entity. A number of studies for the postoperative feeding schedule has been studied to allow for earlier hospital discharge and improve cost-effectiveness in the treatment of HPS. The purpose of this study was to compare 3 feeding-methods and to evaluate the usefulness of ad lib feeding for HPS. The authors retrospectively reviewed the records of 116 patients who underwent pyloromyotomy for HPS from 1995 to 2004. Three cases were excluded because of the duodenal perforation during pyloromyotomy. Three feeding-methods were defined as: Conventional feeding (>10 hours nothing by mouth and incremental feeding every 2 hours, C), Early feeding(for 4 to 8 hours nothing by mouth and incremental feeding every 2 hours, E), and Ad lib feeding (for 4 hours nothing by mouth and ad lib feeding, A). Time to normal feeing in C, E and A were $51{\pm}24$, $34{\pm}12$ and $24{\pm}6$ hours, respectively. Hospital-stay in C, E and A were $72{\pm}17$, $55{\pm}13$ and $43{\pm}12$ hours, respectively. There were statistically significant differences according to the method of feeding. Frequency of postoperative emesis in C, E and A were 38 %, 47 % and 53 %, but was not significant statistically. Ad lib feeding decreased time to normal feeding and hospital stay, and did not increase postoperative emesis. We conclude that ad lib feeding is recommended for patient with pyloromyotomy in HPS.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.66-70
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• 1998

Apoptosis is a form of cell death in which the cells shrink and exhibit nuclear chromatin condensation and DNA fragmentation, and yet maintain membrane integrity. Many lines of evidence have shown that brain neurons are vulnerable to degeneration by apoptosis. Also it has been suggested that apoptosis is one of the mechanism contributing neuronal loss in Alzheimer's disease(AD), since the conditions in the disease($A{\beta}$ peptide, oxidative stress, low energy metabolism) are the inducers that activate apoptosis. Indeed some neurons in vulnerable regions of the AD brain show DNA damage, chromatin condensation, and apoptic bodies. Consistently, mutations in AD causative genes(Amyloid precursor protein, Presenilin-1 and Presenilin- 2) increase $A{\beta}$ $peptide_{1-42}(A{\beta}_{1-42})$ and sensitize neuronal cell to apoposis. However, several lines of evidence have shown that the location of neuronal loss and $A{\beta}$ peptide deposition is not correlated in AD brain and transgenic mice brain over-expressing $A{\beta}_{1-42}$. Taken together, these data may indicated that $A{\beta}$ peptide(and other causative factors of AD) can interact with other cellular insults or risk factors to exacerbate pathological mechansim of AD through apoptosis. Thus, this review discusses possible role and mechanism of apoptosis in AD.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.2
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• pp.213-222
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• 2017

Online advertisement has many benefits comparing to offline advertisement but it also has many challenging problems by online ad abuses. Advertisement injection (Ad injection) is one of the threats that surreptitiously inserts advertisements without a permission of site owners. Users are exposed to additional ads and redundant web traffic by injected ads can cause a service quality problem. Moreover, advertisers can have economic loss when injected ads are different from original ones. Although ad injection leads to these problems it has not been fully studied yet. A few ad injection researches are done by online advertising providers such as Google. In this paper, we analyze ad injection activities to Korean major portal, Naver. We classify 6 types of ad injections and describe their characteristics by analyzing 27 downloaders and 199 installed programs.

• Journal of Physiology & Pathology in Korean Medicine
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• v.31 no.4
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• pp.213-219
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• 2017

Atopic dermatitis (AD) is a common skin disease characterized by chronic and relapsing inflammatory dermatitis with immunological disturbances. Spleen deficiency (脾虛) is one of the major causes of AD, so development of animal model is required for AD research that reflects the pattern identification. The groups that we have used in this study included Senna folium extracts (SFE), 2,4-dinitrochlorobenzene (DNCB), and normal mice. Therefore, the present study was developed to atopic dermatitis mouse model with spleen deficiency in 2,4-dinitrochlorobenzene (DNCB) and senna leaves extracts induced AD in NC/Nga mice. The results demonstrated that senna leaves extract treatment significantly increased the dermatitis clinical score and epidermal thickness in AD-like skin lesions. We also proved beyond doubt that there was occurrence of erythema and skin moisture indices in the senna leaves extract groups. Further, we also found that the level of serum immunoglobulin E (IgE) in the senna leaves extract-treated group was increased. The amount of IL-4, IL-13, $TNF-{\alpha}$ and $TGF-{\beta}$ mRNA determined by real-time PCR was increased remarkably when senna leaves extract groups were treated on dorsal skin. Senna leaves extract groups significantly promoted the number of CD11B+/Gr-1 cell in skin, as well as the number of CD4+/CD8+ cell in dorsal skin compared with control. The review summarizes recent process in our understanding of the immunopathophysiology of spleen deficiency AD and the implications for spleen deficiency mouse models of AD on drug discovery from medical plants.