• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.12
• /
• pp.1685-1689
• /
• 2018

In this research, 51% attack or majority attack is becoming an important security issue for proof of work based blockchains. Due to decentralized nature of blockchains, any attacks that shutdowns the network or which take control over the network is hard to prevent and assess. In this paper, different types of majority attack are summarized and the motivations behind the attacks are explained. To show the feasibility of the majority attack, we build an example mining machines that can take control over two of the public blockchains, Vertcoin and Monero.

• Journal of Applied Reliability
• /
• v.15 no.2
• /
• pp.131-138
• /
• 2015

In modern warfare, the number of unmanned systems grow faster than any other weapon systems. Therefore, it is very important to predict and measure the combat effectiveness (CE) of unmanned weapon systems in battlefield for deciding defense budget to acquire those systems. In general, quantitative calculation of weapon effectiveness under complicated battlefield is difficult based on the future network centric warfare. Hence, many papers studied how to measure the combat effectiveness and tried to study a lot of related issues about it. However, there are few papers dealing with the relationship between the UGV (Unmanned Ground Vehicle)'s performance and CE in a ground battlefield. In this paper, we do the sensitivity analysis based on a given scenario in a small unit battle. In order to do that, we developed simulation model using AnyLogic and changed the input parameters such as detection and hitting probabilities. We also assess the simulation outputs according to the variation of input parameters. The MOE used in this simulation model output is survival ratio for Blue force. We hope that this paper will be useful to find which input variable is more effective to increase combat effectiveness in a small unit ground battlefield.

• Clinical and Experimental Pediatrics
• /
• v.58 no.12
• /
• pp.484-490
• /
• 2015

Purpose: To determine the efficacy and safety of oral propranolol as a first-line treatment for superficially located infantile hemangioma (IH) and propose an assessment tool to measure treatment response. Methods: Patients with superficial IH under 1 year of age were prospectively recruited between May 2012 and December 2013 at the Department of Pediatrics of Chungbuk National University Hospital. Propranolol was administered to 12 infants (median age, 3.8 months) while monitoring cardiovascular and adverse metabolic effects. If a patient showed no adverse events, the dosage was gradually increased up to 3 mg/kg/day and maintained for 1 year. We used our own scoring system to assess treatment response using parameters like change in color, and longest diameter, and thickness of the IH. Results: Eleven out of 12 patients completed the protocol with consistent improvement of hemangiomas during therapy. Patients on propranolol showed a more than 50% involution in the first 3 months, with additional steady involution until 1 year. Patients with the highest scores at 1 month maintained their score and showed better responses until treatment termination. The patient with the lowest score at 1 month did not show any further regression and stopped propranolol treatment 4 months after initiation. In two children with recurrences after successful therapeutic regression, propranolol was effective after being reintroduced. Propranolol treatment was not interrupted in any patient due to adverse events. Conclusion: Oral propranolol at 3 mg/kg/day showed a consistent, rapid, and therapeutic effect on superficial IHs without significant adverse events.

• Proceedings of the Korea Society for Simulation Conference
• /
• 2001.10a
• /
• pp.306-312
• /
• 2001

In this research, we are trying to develop a framework to evaluate the prevention program for Tsunami disaster based on the Multi-agent simulation model. Tsunami has arisen by the earthquake. It happened after flew minutes or few hours when it occurred. It is clear that Tsunami will come after earthquake and from seashore. If we prevent the damage by Tsunami, we should make people who is in the seashore and lived near the seaside escape from there. Moreover we must forecast the escape activity from Tsunami. Former research of this field, some researches try to forecast the escape activity as macro level. However, people who escape from Tsunami is differ from their physical ability and ability of information processing. It needs a more accuracy model to forecast the escape activity of them. Furthermore they make a decision step by step using the various information. Therefore escape activity from Tsunami will describe using an agent based model which can only treat the information processing of human being. In this paper, we develop the evacuation model from Tsunami disaster using the Multi agent based model. The purpose of this study is to analyze the human action pattern when Tsunami occurred, and to make an accurately assessment for damages by Tsunami. The Fujisawa city government is planning and operating the various prevention program far Tsunami. However nobody assess it, because they do not have any simulation models for Tsunami disaster. If they want to set an effective prevention program for Tsunami, they should have any kinds of simulation model. The results of this study are 1) To develop the Multi agent based evacuees escape activity model. 2) Assess the damage of Tsunami in Fujisawa-City.

• Journal of Korean Neurosurgical Society
• /
• v.37 no.2
• /
• pp.116-123
• /
• 2005

Objective: Percutaneous kyphoplasty using a balloon-catheter is an widely accepted method which achieves the restoration of vertebral height and the correction of kyphotic deformity with little complication in osteoporotic vertebral compression fractures. The authors assess the results of 59 patients who underwent kyphoplasty, and analyze the factors that could affect the prognosis. Methods: From December 2001 to May 2003, fifty-nine patients underwent kyphoplasty. The patients included 49 women and 10 men aged 52-85 years. Average t-score on bone marrow density was -3.58. About 7cc of polymethylmethacrylate(PMMA) was injected into the fractured vertebral body using $Kyphon^{(R)}$ under local anesthesia. The vertical height of all fractured vertebrae was measured both before and after surgery. Outcome data were obtained by comparing pre- and post-operative VAS score and by assessing postoperative satisfaction, drug dependency and activity. Various clinical factors were analyzed to assess the relationship with the outcome. Results: The VAS score improved significantly, and the mean percentage of restored vertebral height was 53%. The mean improvement in kyphosis was $3.6^{\circ}$. Eighty-nine percent of the patients gained excellent or good results. Any of the clinical factors including the interval between fracture and operation, the degree of height loss, the degree of the vertebral height restoration or the correction rate of kyphosis did not affect the clinical results. Conclusion: Kyphoplasty is associated with a statistically significant improvement in pain and function with little complication. The clinical results are not affected by any clinical parameters. Further follow-up study is needed to determine whether the restoration affects the long-term clinical results.

• Communications for Statistical Applications and Methods
• /
• v.15 no.3
• /
• pp.465-481
• /
• 2008

Item response theory(IRT) estimates latent ability of a subject based on the property of item and item parameters using item characteristics curve(ICC) of each item case. The initial value and another problems occurs when we try to estimate item parameters of IRT(e.g. the maximum likelihood estimate). Thus, we propose the asymptotic approximation method(AAM) to solve the above mentioned problems. We notice that the proposed method can be thought as an alternative to estimate item parameters when we have small size of data or need to estimate items with local fluctuations. We developed 'Any Assess' and tested reliability of the system result by simulating a practical use possibility.

• Journal of Oral Medicine and Pain
• /
• v.20 no.2
• /
• pp.477-487
• /
• 1995

The purpose of this study was to assess the thermographic differences of craniomandibular area between normal individual and patients with craniomandibular disorders and to compare the differences between clinical and thermographical assessment. The author had used 50 subjects as materials for this study, which was divided into 2 groups (first group included 15 healthy subjects and second group included 35 patients) with craiomandibular disorders; 17 subjects had normal disc-condyle relationship, 13 subjects had disc displacement with reduction and 5 subjects had disc displacement without reduction. Agema 870 thermovision(D.I.T.I.) was used to take thermographs with $0.1^{\circ}C$ difference of gradual temperature shift. The results were as follows : 1. Of 34 patients with craniofacial pain, 15(44%) subjects showed hyperthermia on the pain site in the thermography, 8(23.5%)exhibited hyperthermia on the site opposed to the pain site, and 11(32.4%) did not show any significant thermal change. One patient without craniofacial pain showed hyperthermia on the site opposed to the site of disc displacement without reductin. 2. Of 35 patients with craniofacial pain or disc displacement, 24(68.6%) subjects showed a significant thermal difference between symptomatic and asymptomatic sides of the face, but 11(31.4%) did not show any difference. 3. Of 17 patients with pain but with normal disc-condyle relationship, 8(47.1 subjects showed hyperthermia on the pain site, 4(23.5%) showed on the site opposed to the pain site, and 5(29.4%) did not show any significant thermal change. 4. Or 13 patients with pain and disc displacement with reduction, 6(46.2%) subjects showed hyperthermia on the pain site, 3(23.1%) showed on the site opposed to the pain site, and 4(30.8%) did not show any significant thermal change. 5. 15 healthy subjects did not show any thermal differences between the both sides of the face.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.16
• /
• pp.6845-6849
• /
• 2015

Background: Roles of tobacco and alcohol use in etiology of cancer are well established. Alterationin in P53 have essential roles neoplastic change by preventing genome mutation; the aim of this study was to assess the association between P53 mutation and tobacco and alcohol consumption, as well as to assess the epidemiology of tobacco and alcohol use as risk factors for cancer in the adult population of northern Saudi civilians. Materials and Methods: A cross-sectional survey from October 2014 to January 2015, covering 3,398 adults, was performed. P53 mutation molecular detection was performed for 100 tobacco and alcohol users, usingDNA extracted from buccal cells. Results: Of the 3,398 participants 3,253/3398(95.7%) responded, with a male female ratio of 1.10: 1.00. Out of these, 24.8% had smoked tobacco in their lifetime and 2.7% were consumers of alcoholic beverages. None was identified with any P53 mutation. Conclusions: The prevalence of tobacco smoking among the northern Saudi civilians was relatively high. Females' attitudes in tobacco and alcohol related issues were found to be affected by social stigma. Tobacco and alcohol use has no link to P53 gene mutations.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.2
• /
• pp.479-483
• /
• 2016

Breast cancer is the first or second leading cancer among females across the globe. A large number of studies have been conducted to assess any relationship between vitamin D receptor (VDR) gene polymorphisms and breast cancer development. Epidemiological studies have indicated that ethnic traits exhibited by a group of people with a common ancestry and culture, alter the link between VDR gene and breast cancer. It has been hypothesized that VDR polymorphisms have the capacity to impact both on incidence of breast cancer occurrence and to predict its outcome. A survey was here conducted to assess and compare the impact of vitamin D receptor gene polymorphisms Fok1, Bsm1, Taq1, Apa1 and poly (A) on development of breast cancer. Information was obtained from electronic databases including PubMed and Google Scholar for articles published during the period from 1996 to 2015. This search was achieved by using the terms "genetics", "breast cancer", "VDR gene", "polymorphisms". However, due to inconsistent results, no conclusive statements could be presented about the significance of the VDR genotype as far as the development of breast carcinoma is concerned.

• Journal of Korean Academy of Nursing
• /
• v.31 no.6
• /
• pp.978-987
• /
• 2001

The purpose of this study was to determine the changing patterns of nausea, vomiting, anorexia and calorie intake. To examine the influence of those variables on the nutritional status of the cancer patients receiving chemotherapy. Method: To assess nutritional status, anthropometry and blood test were performed on 94 stomach cancer patients receiving postoperational chemotherapy on the daily basis. NVA and calorie intake were measured during chemotherapy. Result: 93% of subjects had low level of hemoglobin and 45.7% was below the lymphocyte count. 57% of subjects lost 10% of usual weight. The value of anthropometry was reduced but the difference between pre- and post-chemotherapy did not reach any statistical significance. 27% of subjects was grouped into the malnutritional state. During chemotherapy, the higher the degree of NVA, the less calorie intake. The significant predictors for nutritional status were nausea and calorie intake. Conclusion: The chemotherapy affected the food intake of cancer patients through NVA. Though the influence of chemotherapy on anthropopmetry was not significant in this research, nausea and food intake were the most affecting factors for nutrition of cancer patients. Therefore we need to assess nutritional status and support for cancer patients receiving chemotherapy and to develop an intervention for improvement of symptoms and food intake.