• Geomechanics and Engineering
• /
• v.3 no.1
• /
• pp.61-81
• /
• 2011

In this paper, a complement to the Hoek-Brown criterion is proposed in order to derive the strength of anisotropic rock from strength of the corresponding truly intact rock. The complement is a decay function, which unlike other modifications or suggestions made in the past, is multiplied to the function of the original Hoek-Brown failure criterion for intact rock. This results in a combined and extended form of the criterion which describes the strength of anisotropic rock as a varying fraction of the corresponding truly intact rock strength. Statistical procedures and in particular regression analyses were conducted into data obtained in experiments conducted in the current research program and those collected from the literature in order to define the Hoek-Brown's criterion complement. The complement function was best described by a simple polynomial including only three constants to be empirically evaluated. Further investigations also showed that these constants can be related to the other readily available parameters of rock material which further facilitate determining the constants. A great and prime advantage of the proposed complement is that it is mathematically simple including the least possible number of empirical constants which are easily estimated with minimum experimental effort. Moreover, proposed concept does not suggests any change to the original Hoek-Brown criterion itself or its constants and serves whenever anisotropy does exist in the rock. This further implies on the possibility of using any other failure criterion for intact rock in conjunction with the compliment to reach the strength of anisotropic rock.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.3
• /
• pp.2263-2271
• /
• 2015

The thin cylindrical shell structure under compression should be checked with buckling stability. Initial imperfection effects on buckling strength has been investigated by many researchers. Even though there have been a number of these studies, more studies of buckling strength with various initial imperfections are still necessary. In Eurocode, there is a design parameter that is applicable only on specific imperfection by section thickness rather than on various initial imperfection. In this study, structural analyses, using geometry and material nonlinear analysis, of cylindrical buckling strength with various initial imperfection were performed and compared with Eurocode design strength and Finite Element Method (FEM) analysis results. Moreover, the modified design parameter, which gives more exact prediction result of buckling strength under bending with initial imperfection, is proposed for various initial imperfections.

• Animal cells and systems
• /
• v.9 no.2
• /
• pp.101-105
• /
• 2005

[ ${\beta}ig-h3$ ] is a secretory protein that is induced by $TGF-{\beta}$ and implicated in various disease conditions including fibrosis. We have previously reported that ${\beta}ig-h3$ expression is implicated in astrocyte response to brain injury. In this study, we further investigated potential roles of ${\beta}ig-h3$ protein in the injured central nervous system (CNS). We specifically assessed whether the treatment of microglial cells with ${\beta}ig-h3$ can regulate microglial activity. Microglial cells are the prime effector cells in CNS immune and inflammatory responses. When activated, they produce a number of inflammatory mediators, which can promote neuronal injury. We prepared conditioned medium from the stable CHO cell line transfected with human ${\beta}ig-h3$ cDNA. We then examined the effects of the conditioned medium on the LPS- or $IFN-{\gamma}-mediated$ induction of proinflammatory molecules in microglial cells. Preincubation with the conditioned medium significantly attenuated LPS-mediated upregulation of $TNF-{\alpha},\;IL-1{\beta}$, iNOS and COX-2 mRNA expression in BV2 murine microglial cells. It also reduced $IFN-{\gamma}-mediated$ upregulation of $TNF-{\alpha}$ and COX-2 mRNA expression but not iNOS mRNA expression. Assays of nitric oxide release correlated with the mRNA data, which showed selective inhibition of LPS-mediated nitric oxide production. Although the regulatory mechanisms need to be further investigated, these results suggest that astrocyte-derived ${\beta}ig-h3$ may contribute to protection of the CNS from immune-mediated damage via controlling microglial inflammatory responses.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.30 no.3
• /
• pp.246-252
• /
• 2014

$Br{\aa}nemark^{\prime}s$ original protocol required 4 to 6 months for implant osseointegration before placement of the definitive prosthesis. Although this approach gave very predictable results, it had certain drawbacks. The main disadvantages of this approach were prolonged treatment time, two surgical procedures, placement of a removable prosthesis that required modifications during the course of treatment, and a greater number of appointments. Immediate implant loading is a viable treatment method for selected cases. One of the greatest advantages of this method is the virtual surgery, which precedes the actual clinical treatment and eliminates any need for last minute decisions. The actual surgery time is decreased, since all steps are predetermined. These advantages aren't only more useful for normal patients but also for the mental retardation patients whose cooperation is difficult. This article presents a clinical approach made possible due to the guided implant surgery and CAD/CAM technique.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.27 no.2
• /
• pp.123-129
• /
• 2017

Objectives: The purpose of this study is to enhance the application of analytical method of polar solvents(alcohols) by GCOTC (gas chromatography open tubular column) through the system suitability test(SST) to estimate the whole chromatographic system performance(integral part). Methods: To perform the SST, carried out repeatability(n=6) as analytical method of polar solvents by GCOTC, got the retention time($t_R$), standard deviation(${\sigma}_{n-1}$) of $t_R$, baseline width($w_b=4{\sigma}_{n-1}$) and calculated dead time($t_m$) by $v_m=d^2{\pi}L(f/4)$ and $v_m=t_m$ x flow rate. Results: In this experiment, obtained the basic data, there were $t_m=2$ min, methanol($t_R=3.569$, ${\sigma}_{n-1}=0.01$, $w_b=0.04$), ethanol ($t_R=3.892$, ${\sigma}_{n-1}=0.004$, $w_b=0.016$), isopropanol($t_R=4.209$, ${\sigma}_{n-1}=0.004$, $w_b=0.016$). By using these data, calculated the corrected retention time($t_R{^{\prime}}$), capacity factor(k), separation factor(${\alpha}$), number of theoretical plate(n) and resolution($R_s$) for SST and got the good results. Conclusions: Through the SST, could reconfirm the whole chromatographic performance system(integral part) for analytical method of polar solvents by GCOTC. Therefore, this analytical method expect to be widely applied at the related areas.

• Journal of computational fluids engineering
• /
• v.21 no.1
• /
• pp.103-109
• /
• 2016

With the rapid increase in the number of patients with cardiopulmonary diseases, more cardiopulmonary circulatory assist devices are also needed. These devices can be employed when heart and/or lung function poorly. Due to the critical role they take, these devices have to be designed optimally from both mechanical and biomechanical aspects. This paper presents the CFD results of a baseline model of a centrifugal blood pump for the ECMO condition. The details of flow characteristics of the baseline model together with the performance curves and the modified index of hemolysis(MIH) are investigated. Then, the geometry of baseline impeller and the volute are modified in order to improve the biomechanical performance and reduce the MIH value. The numerical simulations of two cases represent that when impeller radius and prime volume decrease the MIH value also decreases. In addition, the modified geometry shows more uniform pressure distribution inside the volute. The findings provide valuable information for further modification and improvement of centrifugal blood pumps from both mechanical and biomechanical aspects.

• Journal of Oriental Neuropsychiatry
• /
• v.20 no.1
• /
• pp.119-146
• /
• 2009

Objectives : In this study, patients with tic disorders who visited an Oriental medicine clinic were examined for their demographic characteristics, characteristics of symptoms, relation to Attention-deficit Hyperactivity Disorder(ADHD) and peculiarity according to various variables such as motor and vocal tics. Methods : After surveying 292 patients who visited an Oriental medicine clinic with tic symptoms as main complaints for 17 months, SAS 9.1, a statistical program was used for statistical analysis. Results : 1. The BMI of male tic patients was significantly higher than female ones and it was similar to or higher than the normal group. 2. Patients who are eldest children were 1.7 times higher than those who are not eldest ones. 3. The most usual case of motor tics was the eye blink and the most one of vocal tics was a dry cough. 4. There was no significant difference between male and female patients for all symptoms of motor and vocal tics, but male patients had significantly more obsessions related to tics than female ones. 5. There was no significant difference in the age of initial occurrence of Transient tic disorder(TTD), Chronic tic disoder(CTD) and Tourette's disorder(TD). 6. For the general disorder of a tic and Conners' ADHD rating scale, there was no significance in TTD, CTD and TD. 7. 66% out of the total subjects of 197 cases were found to score more than 65 points in more than 1 items among 8 items such as the time, hearing, wrong alarm, mean response time and standard deviation in the response time, etc. of the ADHD diagnosis system(ADS). 8. The eye blink among motor tics was shown mainly by patients under 10 years old and the frown, movement of the head, shrug and movement of the arms were shown mainly by 11-19 years old patients. Conclusions : For the number, frequency, seriousness and inconvenience in life of tics, TD showed a significantly higher result than TTD and CTD.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.4
• /
• pp.1745-1754
• /
• 2016

Background: The prime output of Hospital Based Cancer Registries is stage and treatment based survival to evaluate patient care, but because of challenges of obtaining follow-up details a separate study on Patterns of Care and Survival for selected sites was initiated under the National Cancer Registry Programme of India. The results of stage and treatment based survival for head and neck cancers by individual organ sites are presented. Materials and Methods: A standardized Patient Information Form recorded the details and entered on-line at www.hbccrindia.org to a central repository - National Centre for Disease Informatics and Research. Cases from 12 institutions diagnosed between 1 January 2006 and 31 December 2008 comprised the study subjects. The patterns of treatment were examined for 14053 and survival for 4773 patients from five institutions who reported at least 70% follow-up as of 31 December 2012. Results: Surgical treatment with radiation for cancer tongue and mouth showed five year cumulative survival (FCS) of 67.5% and 60.4% respectively for locally advanced stage. Chemo-radiation compared to radiation alone showed better survival benefit of around 15% in both oro and hypo-pharyngeal cancers and their FCS was 40.0%; Hazard Ratio (HR):1.5;CI=1.2-1.9) and 38.7%; (HR):1.7; CI=1.3-2.2). Conclusions: The awareness about the requirement of concurrent chemo-radiation in specifically cancers of the oro and hypopharynx has to be promoted in developing countries. The annual (2014) estimate number of new Head and Neck cancers with locally advanced disease in India is around 140,000 and 91,000 (65%) patients do not receive the benefit of optimal treatment with ensuing poorer survival.

• The Journal of Korean Academy of Prosthodontics
• /
• v.33 no.4
• /
• pp.769-779
• /
• 1995

The understanding the nature of occlusal tooth contacts of natural dentition is important for correct diagnosis and treatment of diseases developed in stomatognatic system. Several investigator have studied the distribution of tooth contacts in maximum intercuspation and have repored contact locations with respect to the tooth position. However, there are few report the variation of the occlusal contact point with change in each head position. This study analysed the number of occlusal contact point with change in each head position. 30 subject(male 17, female 13), who ahad natural occlusion and no symptoms of temporomandibular disorder, were selected. The numbers and patterns of tooth contact were recorded by silicone bite registration on stone model at four different head positions with head anguration gauge(from the supine to the upright position). The results obtained were as follows : 1. The numbers of total occlusal contact point on teeth increased to average 25, 29, 35, 42 points as head angulation was changed from the supine to the upright position against the ala-tragus line, and there was significant difference(P<0.05). 2. In the 19 subject(65%)of total 30 subject, the perforated point of the silicone bite indicated that the locus for the prime contact point moved mesially as the head angulation was changed from the supine to the upright position. 3. On the basis of the fact that the anterior occlusal contact point increase as head angulation changed from the supine to the upright position, we could find that the mandibular position is moved anteriorly.

• Journal of the Korean association of regional geographers
• /
• v.21 no.4
• /
• pp.649-659
• /
• 2015

According to the influence of the LINC project initiated by the Ministry of Education, Science and Technology in 2011, the number of 'University-Industry Collaboration Faculty' has been sharply increased for the last five years. It is viewed that university-industry collaboration faculty have played a prime role for promoting the university-industry collaboration. However, there is a potential threat that about 70 per cents of total expense needed for maintaining the university-industry collaboration faculty system are dependent upon finances of the LINC project. There is a concern that the university-industry collaboration faculty system will be disappeared, if a university or college fails to be selected in the LINC project or the government decides to suspend the LINC project. In order to grasp the realities and policy alternatives on the university-industry collaboration faculty system, this paper conducts a literature survey, a questionnaire survey, the in-depth interviews with experts and the persons concerned. Based on the results of the survey, we suggest policy implications in terms of legal, financial and structural dimensions.