• Coupled systems mechanics
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• v.2 no.3
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• pp.231-253
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• 2013

The impact of spar-nacelle-blade coupling on edgewise dynamic responses of spar-type floating wind turbines (S-FOWT) is investigated in this paper. Currently, this coupling is not considered explicitly by researchers. First of all, a coupled model of edgewise vibration of the S-FOWT considering the aerodynamic properties of the blade, variable mass and stiffness per unit length, gravity, the interactions among the blades, nacelle, spar and mooring system, the hydrodynamic effects, the restoring moment and the buoyancy force is proposed. The aerodynamic loads are combined of a steady wind (including the wind shear) and turbulence. Each blade is modeled as a cantilever beam vibrating in its fundamental mode. The mooring cables are modeled using an extended quasi-static method. The hydrodynamic effects calculated by using Morison's equation and strip theory consist of added mass, fluid inertia and viscous drag forces. The random sea state is simulated by superimposing a number of linear regular waves. The model shows that the vibration of the blades, nacelle, tower, and spar are coupled in all degrees of freedom and in all inertial, dissipative and elastic components. An uncoupled model of the S-FOWT is then formulated in which the blades and the nacelle are not coupled with the spar vibration. A 5MW S-FOWT is analyzed by using the two proposed models. In the no-wave sea, the coupling is found to contribute to spar responses only. When the wave loading is considered, the coupling is significant for the responses of both the nacelle and the spar.

• Proceedings of the Ginseng society Conference
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• 2002.10a
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• pp.456-466
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• 2002

Wild ginseng production is increasing due to forest recovery for last 30 years. Total number of Symmani (traditional mountain ginseng digger) was 558 in 2001. Provincial distribution of Symmani in 2001 was highest in Kangwon $(32\%),$ next in Choongbook $(21\%)$ and least in Jeonnam $(0.7\%)$ and Kyoungnam $(0.9\%).$ Age distribution of Symmani was $33\%\;for\;fourties,\;32\%$ for fifties and $20\%$ for sixties. There were 8 persons in eighties. Symmanies are still keeping traditional ritual for mountain god serving clothes of colored ribbons and foods. Increased production induced open market system from underground dealing of mountain ginseng. Korea Mountain Ginseng Association established mountain ginseng assessment committee with professional Symmanies in 2001. From September to November in 2001, 987 roots were requested for quality assessment to the committee and 476 roots $(48\%)$ were passed and graded and others were rejected. Highest frequency of rejection was foreign origin. Pass rate was highest $(74\%)$ in Choongnam suggesting best place for quality. Number of collected roots in each province was positively correlated (p=0.05) with number of Symmanies. There are 3 quality groups of mountain ginseng, Heaven (pure natural), Earth (from seeding of wild ginseng) and Man (from seeding or seedling of wild ginseng with slight environmental modification). The relationship between price and age was polynomial in high quality root, Heaven, Earth and seed long head of Man group, and linear in low quality group, seedling long head of Man. The best one in 2001 was 26 g, 124 years old and sold with 109 million won. Quality criteria are age, shape, weight, color and healthy outlook. Fine roots are criteria for health status of roots and taproot is criteria for efficacy and called as medicine barrel. The implication is that ginsenosides have rarely been experienced for efficacy. The quality criteria of cultivated ginseng were originated from those of mountain ginseng. It is unique for mountain ginseng that only fresh one can be on market. Since quality criteria of mountain ginseng must be based on the efficacy experience it is well expected that present criteria might almost be established at the age of Shinnong Materia Medica.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.4
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• pp.117-131
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• 2015

Conventional data envelopment analysis (DEA) models require that inputs and outputs are given as crisp values. Very often, however, some of inputs and outputs are given as imprecise data where they are only known to lie within bounded intervals. While a typical approach to addressing this situation for optimization models such as DEA is to conduct sensitivity analysis, it provides only a limited ex-post measure against the data imprecision. Robust optimization provides a more effective ex-ante measure where the data imprecision is directly incorporated into the model. This study aims to apply robust optimization approach to DEA models with imprecise data. Based upon a recently developed robust optimization framework which allows a flexible adjustment of the level of conservatism, we propose two robust optimization DEA model formulations with imprecise data; multiplier and envelopment models. We demonstrate that the two models consider different risks regarding imprecise efficiency scores, and that the existing DEA models with imprecise data are special cases of the proposed models. We show that the robust optimization for the multiplier DEA model considers the risk that estimated efficiency scores exceed true values, while the one for the envelopment DEA model deals with the risk that estimated efficiency scores fall short of true values. We also show that efficiency scores stratified in terms of probabilistic bounds of constraint violations can be obtained from the proposed models. We finally illustrate the proposed approach using a sample data set and show how the results can be used for ranking DMUs.

• Journal of the Korean Solar Energy Society
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• v.37 no.4
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• pp.35-47
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• 2017

Energy efficiency solutions are being pursued as a sustainable approach to reducing energy consumption and related gas emissions across various sectors of the economy. Vacuum Insulation Panel (VIP) is an energy efficient advanced insulation system that facilitates slim but high-performance insulation, based on a porous core material evacuated and encapsulated in a barrier envelope. Although VIP has been applied in buildings for over a decade, it wasn't until recently that efforts have been initiated to propose and adopt a global standard on characterization and testing of VIP. One of the issues regarding VIP is its durability and aging due to pressure and moisture dependent increase of the initial low thermal conductivity with time; more so in building applications. In this paper, the aging of commercially available VIP was investigated experimentally; thermal conductivity was tested in accordance with ISO 8302 standard (guarded hot box method) and long-term durability was estimated based on a non-linear pressure-humidity dependent equation based on study of IEA/ECBCS Annex 39, with the aim of assessing durability of VIP for use in buildings. The center-of-panel thermal conductivity after 25 years based on initial 90% fractile with a confidence level of 90 % for the thermal conductivity (${\lambda}90/90$) ranged from 0.00726-0.00814 (W/m K) for silica core VIP. Significant differences between manufacturer-provided data and measurements of thermal conductivity and internal pressure were observed.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.37-45
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• 2020

The development process of deep learning is an iterative task that requires a lot of manual work. Among the steps in the development process, pre-processing of learning data is a very costly task, and is a step that significantly affects the learning results. In the early days of AI's algorithm research, learning data in the form of public DB provided mainly by data scientists were used. The learning data collected in the real environment is mostly the operational data of the sensors and inevitably contains various noises. Accordingly, various data cleaning frameworks and methods for removing noises have been studied. In this paper, we proposed a method for detecting and removing noises from time-series data, such as sensor data, that can occur in the IoT environment. In this method, the linear regression method is used so that the system repeatedly finds noises and provides data that can replace them to clean the learning data. In order to verify the effectiveness of the proposed method, a simulation method was proposed, and a method of determining factors for obtaining optimal cleaning results was proposed.

• Hwankyungkyoyuk
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• v.15 no.1
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• pp.68-82
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• 2002

My responses to Kim Kyung-Ok's Critique on my critique on the Hungerford approach can be summarized as follows; First, it was argued that possible confusions and misunderstandings around the concept of behavior in REB were mainly caused by Hungerford himself who has used the word in several different ways, from a bunch of overt actions to almost all kinds of responses including cognitive skills, without any clear operational definition of it for more than 20 years. It seems to be needed for future users of the word, 'Behavior' to Prevent unnecessary confusions by providing their operational definition of it. Second, REB is too ambiguous to be a legitimate goal of environmental education and too outcome-oriented to be a meaningful measure for environmental education research. Anyone who accept REB as a goal of EE or a measure for research should clearly suggest procedures and criteria for judging the environmental responsibility of actions under consideration. Third, the Hungerford approach has begun by realizing the limit of a linear traditional behavior change system and has been evolving toward a complex model with dynamic interactions among/between cognitive variables and affective variables. However, it still has one-way structural orientation toward 'Behavior' with no feedbacks. Addition of some feedback processes would make the model more flexible and realistic. Finally, both the Hines model and the Hungeford model were established based on a series of behavioristic studies including three doctoral dissertations equiped with a list of actions which were prejudged to be environmentally responsible by the researchers, not by the learners. What they were primarily interested in was not how mind functions during the learning processes but how learners' behavior can be effectively changed. Considering uncertainty and complexity associated with environmental problems, a great deal of efforts ought to be made toward more context-based and less normative studies applying cognitive psychology and quantitative approaches.

• The Korean Journal of Pain
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• v.34 no.4
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• pp.417-426
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• 2021

Background: Non-cardiac chest pain (NCCP) is a common patient complaint imposing great costs on the healthcare system. It is associated with psychological factors such as depression. The aim of the present study is determining depression predictors in NCCP patients. Methods: The participants of this cross-sectional study were 361 NCCP patients. Patients filled out questionnaires concerning their sociodemographic, lifestyle, and clinical factors (severity of pain, type D personality, somatization, cardiac anxiety, fear of body sensations, and depression). Results: Based on multiple ordinal logistic regression, lack of physical activity (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.09-2.87), sleep quality (OR, 2.98; 95% CI, 1.15-7.69), being a smoker (OR, 1.33; 95% CI, 2.41-4.03), present pain intensity (OR, 1.08; 95% CI, 1.05-1.11), type D personality (OR, 2.43; 95% CI, 1.47-4.03), and somatization (OR, 1.22; 95% CI, 1.15-1.3) were significant predictors of depression in NCCP patients. Additionally, multiple linear regression showed that being unmarried (β = 1.51, P = 0.008), lack of physical activity (β = 1.22, P = 0.015), sleep quality (β = 2.26, P = 0.022), present pain intensity (β = 0.07, P = 0.045), type D personality (β = 1.87, P < 0.001), somatization (β = 0.45, P < 0.001), and fear of bodily sensation (β = 0.04, P = 0.032) increased significantly depression scores in NCCP patients. Conclusions: Physicians should consider the predictors of depression in NCCP patients which can lead to receiving effective psychological consultations and reducing the costs and ineffectual referrals to medical centers.

• Korean Journal of Clinical Pharmacy
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• v.31 no.3
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• pp.237-246
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• 2021

Background: Pembrolizumab, an anti-cancer drug, is known to increase the activity of the immune system, leading to side effects called immune-related adverse events (irAE), including type 1 diabetes. This study analyzed the correlation between blood glucose level and pembrolizumab administration and investigated the covariates that affect those changes in cancer treatment. Methods: The information of 133 adult cancer patients was obtained from the electronic medical record (EMR) to identify the changes in random blood glucose (RBG) levels during the pembrolizumab treatment. Subjects were classified into subgroups according to their baseline RBG level, history of diabetes, and the use of steroids, and linear regression analysis was conducted. In addition, a secondary analysis was performed within the group of subjects having a strong correlation to glycemic change, which was based on the Pearson correlation coefficient being less than -0.7 or greater than +0.7. Univariate and multivariate logistic regressions were conducted to identify the risk factors to glycemic increase. Results: The RBG level tended to descend without significant differences in total patients during the administration period of pembrolizumab. Despite the insignificance, the logistic regression analysis presents that the odds ratios of baseline RBG less than 130 mg/dL, prophylactic steroid use, and higher dose of pembrolizumab per cycle (mg/kg/cycle) were greater than 1. Conclusions: Prophylactic administration of steroids and a higher dose of pembrolizumab per cycle may increase the blood glucose level as irAE in cancer patients with a strong tendency to glycemic change.

• Animal Bioscience
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• v.34 no.12
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• pp.1903-1911
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• 2021

Objective: The objective of this study was to estimate the genetic parameters and various litter trait trends of Danish pigs in South Vietnam, including the number born alive (NBA), number weaned (NW), and litter weight at the 21st day (LW21). Methods: Records of 936 Yorkshire sows with 3361 litters and 973 Landrace sows with 3161 litters were used to estimate the variance components, genetic parameters, and trends of NBA, NW, and LW21. The restricted maximum likelihood method was applied using VCE6 software to obtain the variance components and genetic parameters. Thereafter, the best linear unbiased prediction procedure with an animal model was applied using PEST software to estimate the breeding values of the studied traits. Results: The heritability estimates were low, ranging from 0.12 to 0.21 for NBA, 0.03 to 0.04 for NW, and from 0.11 to 0.13 for LW21. The genetic correlation between the NBA and NW was relatively strong in both breeds, at 0.77 and 0.60 for Yorkshire and Landrace, respectively. Similarly, the genetic correlation between the NW and LW21 was considerably stronger in Landrace pigs (0.71) than in Yorkshire pigs (0.48). The estimates of annual genetic progress were 0.0431, 0.0233, and 0.0461 for NBA, NW, and LW21 in Landrace pigs and 0434, 0.0202, and 0.0667 for NBA, NW, and LW21 in Yorkshire pigs, respectively. Conclusion: The positive genetic trends estimated for the additive genetic values of the selected traits indicated that the current breeding system has achieved favorable results.

• Child Health Nursing Research
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• v.25 no.2
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• pp.234-243
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• 2019

Purpose: The purpose of this study was to investigate associations between self-management and diabetes knowledge, diabetes-related attitudes, family support, and self-efficacy in adolescents with type 1 diabetes mellitus based on the information-motivation-behavior skills model. Methods: Data collection was conducted between March 18 and September 30, 2018. Patients (N=87) aged 12 to 19 years were recruited from the outpatient clinic of S children's hospital and an online community for patient with type 1 diabetes mellitus. Data were analyzed using descriptive statistics, the independent t-test, one-way ANOVA, Pearsons correlation, and hierarchical multiple linear regression with SPSS IBM 23.0, with the two-tailed level of significance set at 0.05. Results: The mean score of self-management in adolescents with type 1 diabetes mellitus was $61.23{\pm}10.00$ out of 80. The regression analysis showed that self-efficacy and family support significantly explained 56.9% of the variance in self-management (F=21.38, p<.001). Self-efficacy (${\beta}=.504$, p<.001) and family support (${\beta}=.188$, p<.001) were significant predictors of self-management. Conclusion: It is necessary to develop individual interventions to improve self-efficacy and family support for adolescents with type 1 diabetes mellitus to help them enhance their self-management.