PREDICTION OF FAILURE CHARACTERISTICS OF SPOT WELDS OF DP AND TRIP STEELS WITH AN EQUIVALENT STRENGTH FAILURE MODEL

J. HA,허훈,J. H. SONG,J. H. LIM 한국자동차공학회 2013 International journal of automotive technology Vol.14 No.1

This paper proposes a new equivalent failure strength model for spot welds under combined axial and shear loading. To evaluate the pure-shear strength of spot welds fabricated under the same welding conditions with a two-layered lap joint, a test fixture and a specimen were newly designed and proposed. The failure tests of spot welds of TRIP590 1.2t,DP780 1.0t, DP780 1.2t, and DP980 1.2t were carried out at seven different loading angles ranging from 0o to 90o at an internal angle of 15o to obtain the failure loads. The failure loads obtained from the experiments were utilized to construct the failure criterion and thus describe the failure behavior of spot welds in the crash analysis or strength analysis of an auto-body. It is noted that the value of β in the failure criterion for spot welds of AHSS is different from the values of conventional steels. The new equivalent failure strength model proposed in this paper was derived from the failure test results to provide a representative failure model that can be used to accurately compare the failure characteristics of different materials under the same conditions.

DRAG REDUCTION OF A PICKUP TRUCK BY A REAR DOWNWARD FLAP

J. HA,S. JEONG,S. OBAYASHI 한국자동차공학회 2011 International journal of automotive technology Vol.12 No.3

The drag reduction of a pickup truck by a rear flap add-on was examined through CFD simulations and wind tunnel experiments. When installed at the rear edge of the roof, the flap increased the cabin back surface pressure coefficient, causing the downwash of the bed flow to be inclined on the tailgate. Thus, the attachment of the bed flow to the tailgate was eliminated; consequently, the drag coefficient was reduced with increasing flap length and downward angle despite the enlarged reverse flow in the wake. However, the drag coefficient did not decrease any further after a specific downward angle was reached because the bed flow increased the drag force at the tailgate and the flap lowered the pressure field above the flap. To maximize the drag reduction effect, the rear downward flap should be designed to have an optimum downward angle.

정신분열병 환자의 임상반응에 따른 혈장 Homovanillic Acid와 혈장 할로페리돌의 변화

구자일,오동열,양병환 大韓神經精神醫學會 1992 신경정신의학 Vol.31 No.1

Nineschizophrenic inpatients were studied under halopendol treatment for the purpose of evaluating the possible correlation between plasma HVA, leuels(P-HVA) plasma halopendol levels (P-haloperidal) and clinical symptom changes. The authors measured plasma HVA and plasma haloperidol levels, and checked BPRS and SAPS scores at baseline, 7th day. 28th day and 56th day of treatment. 1) P-HVA concentrations of total patients were highest on 7th day, then returned to baseline levels on 28th day. but that of drug responder group(6 patients) were highest on pretreatment then decreased below baseline levels on 7th day and continued to decrease till 56th day of treatment. 2) P-HVA concentrations of total patients showed positive correlations with BPRS scores (r=0.28, p<0.l) and-with SAPS scores(r=0.36, p<0.05) and that of drug responder group showed also positive correlations with BPRS scores(r=0.24, p=NS) and with SAPS scores (r=0.45. p<0.0l). 3) P-haloperidol concentrations of total patients showed significant positive correlation with haloperidol doses(r=0.73, p<0.00l) and that of drug responder group showed positive correlation with haloperidol doses(r=0.53. P<0.01). P-haloperidol concentration of drug responder group showed significant negative correlation with BPRS scores(-0.72, P<0.01) and with SAPS scores(-0.59. P<0.001) but that of total patients did not. 4) The haloperidol doses of drug responder group showed meaningful negative correlations with P-HVA(r=-0.38. p=0.03) and with BPRS scores (r=-0.50. P<0.01) and with SAPS scores(r=-0.47. p=0.0l) but that of total patients did not. The authors discussed the meaning of above results.

Seminal Attributes and Semen Cryo-banking of Nepalese Indigenous Achhami (Bos indicus) Bull under Ex-situ Conservation

Pankaj Kumar Jha,Saroj Sapkota,Neena Amatya Gorkhali,Bhoj Raj Pokharel,Ajeet Kumar Jha,Shishir Bhandari,Bhola Shankar Shrestha 사단법인 한국동물생명공학회 2019 한국동물생명공학회지 Vol.34 No.4

The study was conducted to evaluate the seminal attributes and cryo-banking of Achhami (Bos indicus) bull semen. Of two Achhami bulls, 8 ejaculates from each bull were evaluated for seminal attributes. For semen freezing and cryo-banking, 4 ejaculates (having ≥2 mL semen volume, ≥75% of sperm motility and ≥1,000 × 106 cells/mL of sperm concentration) from each bull were used. Semen samples were diluted in egg-yolk-tris-citrate extender using a two-step dilution protocol, and were frozen in liquid nitrogen (LN2) vapour in a styrofoam box. The mean semen volume, colour, sperm mass activity, motility, viability, concentration, abnormal acrosome, midpiece and tail and, abnormal head of two Achhami bulls were 4.4 ± 0.5 mL vs. 2.5 ± 0.2 mL, 2.5 ± 0.1 vs. 2.4 ± 0.1, 3.5 ± 0.1 vs. 3.5 ± 0.1, 77.0 ± 1.1% vs. 78.3 ± 1.3%, 94.4 ± 0.5% vs. 91.0 ± 0.6%, 1137.7 ± 73.7 × 106 cells/mL vs. 1060.0 ± 44.3 × 106 cells/mL, 10.2 ± 0.5% vs. 10.3 ± 0.5% and 6.7 ± 0.5% vs. 8.2 ± 0.3%, respectively. The post-thawed sperm motility and viability were 53.0 ± 2.0% vs. 50.0 ± 0.0% and 80.2 ± 0.4% vs. 73.2 ± 0.7%, while evaluating by computer-assisted sperm analysis (CASA) system, the percentage of the progressive motility, fast motility, slow motility, local motility and immotile sperm were 75%, 68%, 7.4%, 16.6% and 8.6%, respectively. A total number of 620 doses semen straw were cryo-banked. Due to the acceptable post-thawed sperm motility and viability recorded, cryopreservation of Achhami semen is hereby recommended so as to preserve the Achhami breed. For further validation, the fertility will be observed from the produced frozen semen.

Effects of yttrium substitution on structural and electrical properties of barium zirconate titanate ferroelectric ceramics

Priyanka A. Jha,A.K. Jha 한국물리학회 2013 Current Applied Physics Vol.13 No.7

In the present study, structural, dielectric and ferroelectric properties of Ba1-3x/2Yx Zr0.025Ti0.975O3ferroelectric ceramics have been investigated. The compound was synthesized using solid state reaction technique. The effect of yttrium substitution on structural, dielectric and ferroelectric properties was studied using X-ray diffractometer, scanning electron microscopy (SEM), LCR meter and PeE loops. Phase analysis shows the formation of secondary phase YTi2O6 for Y ≥ 2.5 mol% substitution. The microstructural investigation shows that Y substitution significantly reduces the grain size. An increase in Y content up to 2.5 mol% increases the Curie temperature (Tc) initially but decreases subsequently. The maximum dielectric constant at Tc has been observed for 2 mol% Y substitution and with further increase in Y content the dielectric constant decreases considerably. The solubility limit is found to be 2.5 mol% of Y and after that some of the yttrium atoms enter B-sites and leading to the formation of the secondary phase. The PeE loop studies show that there is an increase in the coercive field with increasing Y content.

Seminal Attributes and Semen Cryo-banking of Nepalese Indigenous Achhami (Bos indicus) Bull under Ex-situ Conservation

Pankaj Kumar Jha,Saroj Sapkota,Neena Amatya Gorkhali,Bhoj Raj Pokharel,Ajeet Kumar Jha,Shishir Bhandari,Bhola Shankar Shrestha 한국동물생명공학회(구 한국동물번식학회) 2019 Journal of Animal Reproduction and Biotechnology Vol.34 No.4

The study was conducted to evaluate the seminal attributes and cryo-banking of Achhami (Bos indicus) bull semen. Of two Achhami bulls, 8 ejaculates from each bull were evaluated for seminal attributes. For semen freezing and cryo-banking, 4 ejaculates (having ≥2 mL semen volume, ≥75% of sperm motility and ≥1,000 × 106 cells/mL of sperm concentration) from each bull were used. Semen samples were diluted in egg-yolk-tris-citrate extender using a two-step dilution protocol, and were frozen in liquid nitrogen (LN2) vapour in a styrofoam box. The mean semen volume, colour, sperm mass activity, motility, viability, concentration, abnormal acrosome, midpiece and tail and, abnormal head of two Achhami bulls were 4.4 ± 0.5 mL vs. 2.5 ± 0.2 mL, 2.5 ± 0.1 vs. 2.4 ± 0.1, 3.5 ± 0.1 vs. 3.5 ± 0.1, 77.0 ± 1.1% vs. 78.3 ± 1.3%, 94.4 ± 0.5% vs. 91.0 ± 0.6%, 1137.7 ± 73.7 × 106 cells/mL vs. 1060.0 ± 44.3 × 106 cells/mL, 10.2 ± 0.5% vs. 10.3 ± 0.5% and 6.7 ± 0.5% vs. 8.2 ± 0.3%, respectively. The post-thawed sperm motility and viability were 53.0 ± 2.0% vs. 50.0 ± 0.0% and 80.2 ± 0.4% vs. 73.2 ± 0.7%, while evaluating by computer-assisted sperm analysis (CASA) system, the percentage of the progressive motility, fast motility, slow motility, local motility and immotile sperm were 75%, 68%, 7.4%, 16.6% and 8.6%, respectively. A total number of 620 doses semen straw were cryo-banked. Due to the acceptable post-thawed sperm motility and viability recorded, cryopreservation of Achhami semen is hereby recommended so as to preserve the Achhami breed. For further validation, the fertility will be observed from the produced frozen semen.

Alzheimer's Disease Detection Using Extreme Learning Machine, Complex Dual Tree Wavelet Principal Coefficients and Linear Discriminant Analysis

Jha, Debesh,Alam, Saruar,Pyun, Jae-Young,Lee, Kun Ho,Kwon, Goo-Rak American Scientific Publishers 2018 Journal of medical imaging and health informatics Vol.8 No.5

Association of Type II Diabetes Mellitus with Hepatocellular Carcinoma Occurrence - a Case Control Study from Kathmandu Valley

Jha, Dipendra Kumar,Mittal, Ankush,Gupta, Satrudhan Pd.,Pandeya, Dipendra Raj,Sathian, Brijesh Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.10

Objective: To assess associations of Type II DM with hepatocellular carcinoma occurrence in Nepal. Materials and Methods: This case control study was carried out using data retrieved from the register maintained in the Department of Biochemistry of Nepalese Army Institute of Health Sciences between 1st January, 2012, and 31st August, 2012. The variables collected were age, gender, HbA1c. All biochemical parameters were analyzed in the Central Laboratory of our hospital by standard validated methods. One way ANOVA was used to examine the statistical significant difference between groups with the LSD post-hoc test for comparison of means of case groups. Odds ratios (OR) were calculated using simple logistic-regression analysis. Results: Etiological factors for HCC were HBV, HCV, alcohol and cryptogenic cirrhosis. The highest age group belonged to the etiological category of HCV with a mean of $71.9{\pm}3.6$ (CI 69.3, 74.5) years and the lowest age group to the etiological category of HBV with $61.7{\pm}5.3$(CI 57.9, 65.5) years. The main imperative basis of HCC in present study was HCV (39.5%) and second most significant cause of HCC was alcohol (26%). Glycated hemoglobin was found to be more in males with HCC (7.9%) as compared to females (7.3%). The percentage of Type II diabetes mellitus was greater in HCC patients when compared to controls. This difference was statistically significant with an odd ratio of 4.63 (p<0.001). Conclusion: Type II DM influences incidence, risk of recurrence, overall survival, and treatment-related complications in HCC patients.

Vulnerability and Responses to Risk in Rural India

Jha, Raghbendra,Kang, Woojin(강우진),Nagarajan, Hari K.,Pradhan, Kailash C. 한국외국어대학교 인도연구소 2020 남아시아연구 Vol.26 No.3

인도의 비 도시 지역 패널 가계조사를 활용하여 비 도시 지역 가계들의 취약성을 추정한 결과 빈곤과 가계 단위의 개별적인 소득충격이 가계 취약성에 크게 영향을 미치는 것으로 나타났다. 이들 가계들은 저축, 현금 이전, 자산처분 등과 같은 가계단위에서의 비공식적 수단을 동원하여 위험에 대처하고 있다. 그러나 소비수준이 소득변화에 크게 연동되어 움직인다는 사실은 그와 같은 비공식적인 자구책이 소득감소에 대한 완충역할을 충분히 하지 못하고 있음을 의미한다. 한편, 공적 위기대처 방안의 경우 가계취약성을 줄이는 것으로 나타났으나 이들 프로그램에 대한 접근은 매우 제한적이다. 이에 따라 인도 정부는 접근성과 정책조준성이 뛰어난 공적 사회안전망을 수립 할 필요가 있으며 정부지원 프로그램의 확대는 소득 충격의 상황에서 가계소비 평준화에 큰 역할을 할 것으로 기대된다. Drawing upon a representative panel household survey for rural India, this paper demonstrates that household vulnerability in rural India is largely explained by poverty and idiosyncratic components. So far as risk coping strategies go, households rely heavily on informal instruments such as their own saving, transfers or capital depletion. Household consumption, however, is highly covariate with income and this implies that existing informal insurance instruments are not sufficient to protect household consumption against income shocks. Hence, an important policy implication of our analysis is that the government should provide readily accessible and well-targeted public safety nets given that the existing informal strategy is not very effective as a consumption insurance mechanism. Although the public risk coping programme is found to reduce vulnerability, access to such programmes is constrained. Expansion of government sponsored coping programmes is likely to protect households effectively from negative shocks.

Energy Based Multiple Refitting for Skinning

Jha, Kailash Society for Computational Design and Engineering 2005 International Journal of CAD/CAM Vol.5 No.1

The traditional method of manipulation of knots and degrees gives poor quality of surface, if compatibility of input curves is not good enough. In this work, a new algorithm of multiple refitting of curves has been developed using minimum energy based formulation to get compatible curves for skinning. The present technique first reduces the number of control points and gives smoother surface for given accuracy and the surface obtained is then skinned by compatible curves. This technique is very useful to reduce data size when a large number of data have to be handled. Energy based technique is suitable for approximating the missing data. The volumetric information can also be obtained from the surface data for analysis.