• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3602-3608
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• 2013

Saccharomyces cerevisiae, which is a common species of yeast, is by far the most extensively studied model of a eukaryote because although it is one of the simplest eukaryotes, its basic cellular processes resemble those of higher organisms. In addition, yeast is a commercially valuable organism for ethanol production. Since the yeast data can be extrapolated to the important aspects of higher organisms, many researchers have studied yeast metabolism under various conditions. In this report, we analyzed and compared metabolites of Saccharomyces cerevisiae under salt and pH stresses of various strengths by using two-dimensional NMR spectroscopy. A total of 31 metabolites were identified for most of the samples. The levels of many identified metabolites showed gradual or drastic increases or decreases depending on the severity of the stresses involved. The statistical analysis produced a holistic outline: pH stresses were clustered together, but salt stresses were spread out depending on the severity. This work could provide a link between the metabolite profiles and mRNA or protein profiles under representative and well studied stress conditions.

• Computers and Concrete
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• v.10 no.5
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• pp.489-505
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• 2012

This paper presents a simplified grid beam model for simulating the nonlinear response of reinforced concrete flat-plate structures. The beam elements are defined with nonlinear behavior for bending moment and torsion. The flexural stiffness and torsional strength of the beam elements are defined based on experimental data to implicitly account for slab two-way bending effects. A failure criterion that considers the interaction between the punching strength and slab flexural behavior is incorporated in the model. The effects of bond-slip of slab reinforcement on connection stiffness are examined. The proposed grid beam model is validated by simulating large-scale tests of slab-column connections subjected to concentric gravity loading and unbalanced moment. This study also determines the critical parameters for a hysteretic model used to simulate flat-plates subjected to cyclic lateral loading.

• The Journal of the Korean dental association
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• v.15 no.4
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• pp.301-304
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• 1977

우리인체의 언어기관은 중추신경에서부터 근육에 이르기까지 광번위한 부분이다. 언어9발성)기관을 근육의 단계에서 볼 때는 다음의 세 가지 model(모형)으로써 언어생성(발성) 과정을 설명할 수 있다. 첫째 모형은 해부학적인 모형으로써 언어생성에 어떠한 근육들이 작용하는가를 볼 수 있고 두째번 모형은 생리학적인 모형으로 언어생성과정의 기능적인 면을 볼 수 있고 셋째번 모형은 물리학적 모형으로 말소리의 물리학적인 성질을 이해하는데에 도움을 준다. 이 세 가지 모형을 이용해서 언어생성 과정을 간결하게 설명했다.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.58.1-58.1
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• 2014

We model the polarized dust emission from aligned grains by radiative torques in molecular clouds. We consider various models of molecular clouds and calculate the polarization spectrum from aligned grains by both internal and external radiation fields. We show that some polarization spectrum exhibits the bump at wavelengths ${\lambda}$ < $100{\mu}m$, which can be explained due to the polarized emission from a population of small grains aligned by internal radiation fields. Our polarization spectra can explain the anomalous spectra observed by Hildebrand et al, with the rising polarization toward short wavelengths

• Journal of Mechanical Science and Technology
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• v.14 no.3
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• pp.338-349
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• 2000

Neck muscle forces and spinal loads at the C4/5 level were estimated that result from isometric voluntary ramp efforts gradually developing to maximums in flexion, extension, left lateral bending and right lateral bending. Electromyographic (EMG) activities, a three-dimensional anatomic data of the neck and a hybrid model, EMG-assisted optimization (EMGAO) model, were used. The model computed the cervical loads at 25%,50%,75%, and 100% of peak moments. The highest model-predicted C4/5 joint compressive forces occurred during flexion; $361\;({\pm}164)\;N,\;811\;({\pm}288)\;N,\;1207\;({\pm}491)\;N\;and\;1674\;({\pm}319)\;N$ in 25%, 50%, 75% and 100% of peak moment respectively. Variations in load distribution among the agonistic muscles and co-contractions of antagonistic muscles were estimated during ramp efforts. Results suggest that higher C4/5 joint loads than previously reported are possible during isometric, voluntary muscle contractions. These higher physiological loads at C4/5 level must be considered possible during orthopedic reconstruction at this level.

• The Korean Journal of Applied Statistics
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• v.25 no.6
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• pp.947-958
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• 2012

When modeling event times in biomedical studies, the outcome might be incompletely observed. In this paper, we assume that the outcome is recorded as current status failure time data. Despite well-developed literature the routine practical use of many current status data modeling methods remains infrequent due to the lack of specialized statistical software, the difficulty to assess model goodness-of-fit, as well as the possible loss of information caused by covariate grouping or discretization. We propose a model based on pseudo-observations that is convenient to implement and that allows for flexibility in the choice of the outcome. Parameter estimates are obtained based on generalized estimating equations. Examples from studies in bile duct hyperplasia and breast cancer in conjunction with simulated data illustrate the practical advantages of this model.

• Communications for Statistical Applications and Methods
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• v.28 no.2
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• pp.189-204
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• 2021

In a regression analysis, a single best model is usually selected among several candidate models. However, it is often useful to combine several candidate models to achieve better performance, especially, in the prediction viewpoint. Model combining methods such as stacking and Bayesian model averaging (BMA) have been suggested from the perspective of averaging candidate models. When the candidate models include a true model, it is expected that BMA generally gives better performance than stacking. On the other hand, when candidate models do not include the true model, it is known that stacking outperforms BMA. Since stacking and BMA approaches have different properties, it is difficult to determine which method is more appropriate under other situations. In particular, it is not easy to find research papers that compare stacking and BMA when regression model assumptions are violated. Therefore, in the paper, we compare the performance among model averaging methods as well as a single best model in the linear regression analysis when standard linear regression assumptions are violated. Simulations were conducted to compare model averaging methods with the linear regression when data include outliers and data do not include them. We also compared them when data include errors from a non-normal distribution. The model averaging methods were applied to the water pollution data, which have a strong multicollinearity among variables. Simulation studies showed that the stacking method tends to give better performance than BMA or standard linear regression analysis (including the stepwise selection method) in the sense of risks (see (3.1)) or prediction error (see (3.2)) when typical linear regression assumptions are violated.

• 한국노년학
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• v.32 no.3
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• pp.729-745
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• 2012

The purpose of this study is to review person-centered care models and the scientific evidence for the impact of person-centered care in U.S. nursing homes, and to analyze the applicability of person-centered care for Korean long-term care system. The most commonly recognized person-centered care models were Eden Alternative, Green House, and Wellspring model. The core components of the three models were autonomy, close relationships, homelike environment, and staff empowerment. Thirty eight empirical studies including 10 model testing studies and 28 studies to examine the impact of person-centered care interventions indicated generally positive outcomes in terms of residents, family, and staff/organization level. The authors analyzed the current situation in the Korean long-term care system with respect to the specific core constructs of person-centered care, and proposed applicable models and practical suggestions in consideration of Korean context. Lastly, future considerations regarding policy and research were discussed.

• Journal of Korean Society for Atmospheric Environment
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• v.25 no.3
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• pp.219-236
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• 2009

Particle-phase organic tracers (molecular markers) have been shown to be an effective method to assess and quantify the impact of sources of carbonaceous aerosols. These molecular markers have been used in chemical mass balance (CMB) models to apportion primary sources of organic aerosols in regions where the major organic aerosol source categories have been identified. As in the case of all CMB models, all important sources of the tracer compounds must be included in a Molecular Marker CMB (MM-CMB) model or the MMCMB model can be subject to biases. To this end, the application of the MM-CMB models to locations where reasonably accurate emissions inventory of organic aerosols are not available, should be performed with extreme caution. Of great concern is the potential presence of industrial point sources that emit carbonaceous aerosols and have not been well characterized or inventoried. The current study demonstrates that emissions from industrial point sources in the St. Louis, Missouri area can greatly bias molecular marker CMB models if their emissions are not correctly addressed. At a sampling site in the greater St. Louis Area, carbonaceous aerosols from industrial point sources were found to be important source of carbonaceous aerosols during specific time periods in addition to common urban sources (i.e. mobile sources, wood burning, and road dust). Since source profiles for these industrial sources have not been properly characterized, method to identify time periods when point sources are impacting a sampling site, needs to avoid obtaining biases source apportionment results. The use of real time air pollution measurements, along with molecular marker measurements, as a screening tool to identify when point sources are impacting a receptor site is presented.

• Research in Community and Public Health Nursing
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• v.13 no.2
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• pp.260-271
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• 2002

Objectives: The purpose of this study was to identify basic health needs of adult clients to develop a community nursing center model in Seoul. Methods: Data were collected using a questionnaire survey from 894 adults registered at a public health center who were health management members, and visiting 4 community nursing centers, University of Wisconsin, Milwaukee during the period from July 1999 to January 2000. The data were analyzed using frequency, percentile, t-test, and ANOVA. Results: 1) The University of Wisconsin- Milwaukee School of Nursing has a long tradition of developing 4 community nursing centers with innovative health care programs. CNCs integrate the ability to implement and test effective intervention strategies with education, research, and practices of nursing students and faculty. They were designed to enhance the health status and quality of life for urban communities through the development of productive, outcome focused, collaborative partnerships among UWM-Nursing faculties and staff, other health and human service providers, consumers, and policy makers. It links the financial resources between UWM and 9 voluntary agencies and 12 public funding organizations including federal. state, and local governments. 2) Of the total health management members, 37.4% were reported to have at least one type of chronic disease such as hypertension, diabetes, and arthritis. Ten percent of them reported having obesity, and 44.2% reported lack of exercise. The health status of the subjects was within normal range in laboratory tests. However, female subjects showed more significant differences in obesity and cholesterol levels than male subjects. The subjects, who were in their 50s, showed more significant differences in obesity, SGOT, SGPT, and cholesterol levels than the subjects in other age groups. Conclusion: A community nursing center needs to be developed, that has a link between the nursing college and the public health center, with partnerships and a multidisciplinary approach. Based on the study results, exercise programs for middle aged adults are considered necessary. In particular, specific exercise programs for pre-menopausal women needs to be implemented in the future to prevent them from developing osteoporosis.