• Proceedings of the KSME Conference
• /
• 2007.05a
• /
• pp.694-699
• /
• 2007

The spacer grid set is a part of a nuclear fuel assembly. The set has a spring and the spring supports the fuel rods safely. Although material nonlinearity is involved in the deformation of the spring,nonlinearity has not been considered in design of the spring. Recently a nonlinear response structural optimization method has been developed using equivalent loads. It is called nonlinear response optimization equivalent loads (NROEL). In NROEL, the external loads are teansformed to the equivalent loads (EL) for linear static analysis and linear response optimization is carried out based on the EL in a cyclic manner until the convergence criteria are satisfied. EL is the load set which generates the same response no EL. The objective function is defined by minimizing the maximum stress in the spring while is limited and the support force of the spring is larger than a certain value. The results are verified by nonlinear. ABAQUS is used for nonlinear response analysis and GENESIS is employed for linear response optimization.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.4
• /
• pp.426-435
• /
• 2016

Objectives: The major objective of this study was to analyze stress response after a change to consecutive day shifts from day and night shifts in a motor assembly factory. Methods: Using a survey conducted by a labor union, we collected data on stress response index(SRI), lifestyle factors, work-family conflict and job stress before and after a shift system change. We analyzed the transition on the SRI among 222 workers. The cut-off point for the SRI was a T-score over 60. Results: The high risk stress response group was 20.3% of the population before the shift system change. After the shift system change it decreased to 11.3%. After the shift system change, social support improved, leisure time became more sufficient, work-family conflict declined, and sleep quality in the night shift week improved. In multivariable linear regression, among workers under 40 years old sleep quality on night shift, leisure time sufficiency, social support and work-family conflict contributed to the improvement of stress response. Among workers over 40, work-family conflict contributed to the improvement of stress response. Conclusions: The change to consecutive day shifts improved stress response and mediated with improved nighttime sleep, decreased work-family conflict, increased leisure time and improved work-family conflict.

• Journal of Society of Preventive Korean Medicine
• /
• v.13 no.2
• /
• pp.27-38
• /
• 2009

Objective : This study was to examine a relationship among subjective psychological stress, physical stress response and oxidative stress. Methods : The subjects were consisted of 87 healthy volunteers. To assess subjective psychological stress, SRI(stress response inventory) was completed. To assess psychological and physical stress response, HRV(Heart Rate Variability) were tested. To assess oxidative stress, d-roms(Derivatives of reactive oxygen metabolites test) test was conducted. Subjects were divided into 3 groups depending on SRI(Stress Response Inventory) score, low stress response(LSR: lower than 30 percentile), Medium(MSR: 30-70 percentile) and high stress response(HSR: higher than 70 percentile). The Relationship between Stress Response and Oxidative Stress was estimated by correlation and One-way ANOVA analysis. Results : There were no significant differences of demographic data among 3 groups. There was a significant difference of oxidative stress among 3 groups. Conclusion : Our results suggest that there is a weak positive correlation between subjective psychological stress and oxidative stress. There is a significant difference of oxidative stress between HSR group and LSR group.

• The Journal of Asian Finance, Economics and Business
• /
• v.2 no.2
• /
• pp.13-18
• /
• 2015

In this paper the DRC model is presented for solving multi objective problem. The proposed model is a combination of data envelopment analysis, Cuckoo algorithm and the response surface method. Due to reasons like costs, time and irreversible damages, it is not possible to analyze each and every one of the proposed models in practice, so the simulation is used. Since the number of experiments for simulation process is high then the optimization has gone to practice and directs the simulation process. The response surface method is used as one of the approaches of simulation optimization. Furthermore, data envelopment analysis is used to consider several response surfaces as efficiency response surface. Then this efficiency response surface is solved by Cuckoo algorithms. The main advantage of DRC model is to make one efficiency response surface function instate of multi surface function for every output and also using the advantages of Cuckoo algorithms. In order to demonstrate the effectiveness of the proposed approach, the branches of Refah bank in Mashhad is analyzed and the results are presented.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.1
• /
• pp.184-189
• /
• 2014

This paper presents a multi-objective optimization approach to design rotor slot geometry of three-phase squirrel cage induction machine to achieve NEMA design D torque-speed (T-S) characteristics with high efficiency. The multi-objective Particle Swarm Optimization (MOPSO) algorithm combined with the adaptive response surface method and Latin hypercube sampling strategy is applied to obtain the Pareto optimal designs. In order to demonstrate the validity of the suggested optimal algorithm, an application to rotor slot design of three-phase induction motor is presented.

• Journal of the Korean Society of Safety
• /
• v.37 no.6
• /
• pp.60-70
• /
• 2022

This paper proposes an optimal design method of a seismic reinforcement system for the seismic performance of adjacent asymmetric-stiffness structures with viscous dampers. The first method considers plan asymmetry for efficient seismic reinforcement, and evaluates the seismic performance of optimal design applied to two cases of modeling: adjacent stiffness-asymmetric structures and adjacent stiffness-symmetric structures. The second method considers the response of asymmetric structures to derive the optimal objective function, and evaluates seismic efficiency of the objective function applied to two cases of responses: horizontal displacement and torsion. Numerical analyses are conducted on 7- and 10-story structures with a uni-asymmetric-stiffness plan using six cases of historic earthquakes, normalized to 0.4g. The results indicate that the seismic performance is excellent as modeled by adjacent asymmetric-stiffness structures and how much horizontal displacement is applied as the objective function.

• Journal of Advanced Marine Engineering and Technology
• /
• v.13 no.1
• /
• pp.69-76
• /
• 1989

This paper presents a method of the optimum design for rotating shaft of centrifugal pump. That is, the object is to optimize the system in stability at the operating speed, unbalance response in the vicinity of the rotor critical speed, leakage flow of the seals. The objective function is composed of these three elements and is minimized by changing seal cleareance, diamoters, and lengths. A typical double suction centrifugal pump is analyzed and its objective function is presented. Then the optimum dimensions of seals are obtained, and vibration characteristics at both initial and optimum conditions are investigated.

• Journal of the Korea Society for Simulation
• /
• v.10 no.3
• /
• pp.31-46
• /
• 2001

Repeated measurements on units under different conditions are common in biological and biomedical studies. In a number of growth and pharmacokinetic studies, the relationship between the response and the covariates is assumed to be nonlinear in some unknown parameters and the form remains the same for all units. Nonlinear random coefficient models are used to analyze such repeated measurement data. Extended least squares methods are proposed in the literature for estimating the parameters of the model. However, neither objective function has closed form expression in practice. This paper proposes Monte Carlo methods to estimate the objective functions and the corresponding estimators. A simulation study that compare various methods is included.

• The Journal of Korean Academy of Sensory Integration
• /
• v.9 no.1
• /
• pp.45-52
• /
• 2011

Objective : The aim of this study was to provide the method to measure physiologic response using equipments and auditory stimulation, and the physiologic response features of adult psychiatric disorders through a systemic review. Methods : The systemic review was executed using PubMed. The key words for search were "auditory stimulation, auditory startle, electromyograph, skin conductance, heart rate, psychiatric disorder, anxiety disorder, schizophrenia, depression". 8 studies were used for data analysis, and all of levels of evidence were level II. The substances of the review were subject(population), auditory stimulation, measure equipments and physiologic response features of psychiatric disorder. Results : 1. The subjects for the studies were anxiety disorder(4) and schizophrenia(4). 2. Auditory stimulation was used in 8 studies and visual stimulation with auditory stimulation was used in 2 studies to induce physiologic response. 3. Every study used electromyograph, and skin conductance was used in 2 studies and heart rate was used in 2 studies with electromyograph to measure physiologic response. 4. The subjects for the studies, schizophrenia and anxiety disorder(PTSD, OCD) have different physiologic response features with the normal control group. Conclusion : All studies used simple tones as an auditory stimulation and electromyograph to measure physiologic response. Psychiatric disorders indicated larger response, shorter and delayed habituation. The objective and systematic study using physiologic measure to investigate the sensory feature of psychologic disorders.

• Korean Journal of Radiology
• /
• v.22 no.3
• /
• pp.366-375
• /
• 2021

Objective: To evaluate the radiological tumor response patterns and compare the response assessments based on immune-based therapeutics Response Evaluation Criteria in Solid Tumors (iRECIST) and RECIST 1.1 in metastatic clear-cell renal cell carcinoma (mccRCC) patients treated with programmed cell death-1 (PD-1) inhibitors. Materials and Methods: All mccRCC patients treated with PD-1 inhibitors at Henan Cancer Hospital, China, between January 2018 and April 2019, were retrospectively studied. A total of 30 mccRCC patients (20 males and 10 females; mean age, 55.6 years; age range, 37-79 years) were analyzed. The target lesions were quantified on consecutive CT scans during therapy using iRECIST and RECIST 1.1. The tumor growth rate was calculated before and after therapy initiation. The response patterns were analyzed, and the differences in tumor response assessments of the two criteria were compared. The intra- and inter-observer variabilities of iRECIST and RECIST 1.1 were also analyzed. Results: The objective response rate throughout therapy was 50% (95% confidence interval [CI]: 32.1-67.9) based on iRECIST and 30% (95% CI: 13.6-46.4) based on RECIST 1.1. The time-to-progression (TTP) based on iRECIST was longer than that based on RECIST 1.1 (median TTP: not reached vs. 170 days, p = 0.04). iRECIST and RECIST 1.1 were discordant in 8 cases, which were evaluated as immune-unconfirmed PD based on iRECIST and PD based on RECIST 1.1. Six patients (20%, 6/30) had pseudoprogression based on iRECIST, of which four demonstrated early pseudoprogression and two had delayed pseudoprogression. Significant differences in the tumor response assessments based on the two criteria were observed (p < 0.001). No patients demonstrated hyperprogression during the study period. Conclusion: Our study confirmed that the iRECIST criteria are more capable of capturing immune-related atypical responses during immunotherapy, whereas conventional RECIST 1.1 may underestimate the benefit of PD-1 inhibitors. Pseudoprogression is not rare in mccRCC patients during PD-1 inhibitor therapy, and it may last for more than the recommended maximum of 8 weeks, indicating a limitation of the current strategy for immune response monitoring.