• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.92-99
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• 2016

A wind turbine is controlled for the purpose of obtaining the maximum power below its rated wind speed. Among the methods of obtaining the maximum power, TSR (Tip Speed Ratio) optimal control and P&O (Perturbation and Observation) control are widely used. The P&O control algorithm using the turbine power and rotational speed is simple, but its slow response is a weak point. Whereas TSR control's response is fast, it requires the precise wind speed. A method of measuring or estimating the wind speed is used to obtain a precise value. However, estimation methods are mostly used, because it is difficult to avoid the blade interference when measuring the wind speed near the blades. Neural networks and various numerical methods have been applied for estimating the wind speed, because it involves an inverse problem. However, estimating the wind speed is still a difficult problem, even with these methods. In this paper, a new method is introduced to estimate the wind speed in the wind-power graph by using the turbine power and rotational speed. Matlab/Simulink is used to confirm that the proposed method can estimate the wind speed properly to obtain the maximum power.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.214-226
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• 1992

In this paper, the characteristics of fatigue crack growth in the spot welded joint of the same kinds of specimens($HS{\times}HS,\;GA{\times}GAB$) and different kinds of specimens($HS{\times}GA,\;HS{\times}GAB$) which consist of dual phase high strength steel(HS) and monogalvanized steel(GA) were examined with static tension tests and axial tension fatigue tests. Some of the important results are as follows : 1. The divergence of tensile strengths among the same and different kinds of spot welds under the same conditions is comparatively low regardless of the difference of stiffness. 2. At the low load bevel and long life legion, the fatigue crack is initiated near the nugget. However, in the high load level and short life region, it occurs a tittle far from the nugget. 3. It has shown a linear relation between maximum stress Intensity factor, Kmax and fatigue life, $N_f$ among each of the spot welds and has gathered in a narrow band on the log-log graph paper. $Kmax=H{\cdot}{N_f}^{P}$ where H and P are a material constant.

• Journal of Korean Society of Forest Science
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• v.110 no.4
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• pp.658-664
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• 2021

This study aimed to develop accurate status site index curves for C. japonica in Gyeongsang-do that reflect the regional characteristics. The development of high-growth models in Chapman-Richards, Schumacher, and Gompertz for 552 C. japonica growing in Gyeongsang-do. The Gompertz growth function is the most suitable for developing site index curves. The comparative test was analyzed using the F test at a significance level of 5% and the graph. As a result, compared with the national site index curves and site index curves under base age in Jeolla-do, the p-value was 0.05 or higher, and there was no statistically significant difference. The p-value was 0.05 or lower compared with site index curves over stand age in Jeolla-do, indicating a statistically significant difference. Therefore, it was determined that site index curves for C. japonica in Gyeongsang-do can be applied to the national site index curves and site index curves under base age in Jeolla-do, but not to site index curves over base age in Jeolla-do. Hence, based on the results of the study, it is possible to provide basic data on the forest management system for C. japonica in Gyeongsang-do and systematic and reasonable management through high field application reflecting regional characteristics.

• Applied Chemistry for Engineering
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• v.35 no.3
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• pp.222-229
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• 2024

The use of low-toxic, hypoallergenic, and environmentally friendly natural pigments has increased. With growing interest in health, research on natural extracts containing beneficial substances for the human body is actively underway. In this study, natural pigments were extracted from sprout barley using a solvent extraction method and CCD-RSM was used to optimize the extraction process. The experiment's independent variables included extraction temperature, alcohol/ultra-pure volume ratio, and extraction time. The response variables were set to achieve a target chromaticity (L = 45, a = -35, b = 45), and to maximize DPPH radical scavenging activity evaluating the antioxidant capacity. The statistical significance of the main effect, interaction effect, and effect on the response value was evaluated and analyzed through the F and P values for the regression equation variables calculated using RSM optimization. Additionally, the reliability of the experiment was also confirmed through the P values of the probability plot graph. The extraction conditions for optimizing the four reaction values are 76.1 vol.% alcohol/ultra pure water volume ratio, an extraction temperature of 52.9 ℃ , and an extraction time of 49.6 min. Under these conditions, the theoretical values of the reaction values are L = 45.4, a = -36.8, and b = 45.0 DPPH radical scavenging activity = 30.9%. When the actual experiment was conducted under these optimal extraction conditions and analyzed, the measured values were L = 46.2, a = -36.1, and b = 48.2, and antioxidant capacity = 31.1% with an average error rate of 2.9%.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.6
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• pp.2909-2912
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• 2012

Aim: To evaluate efficacy and tolerability of topotecan treatment for recurrent small cell lung carcinoma. Patients and Methods: A total of 62 patients were evaluated retrospectively. Statistical analysis was performed using GraphPad Instat (version 3.05). Results: DFifty five of patients (89%) were male and 7 (11%) were female. Median age was $56.7{\pm}9.3$ (34-75). Forty eight of patients (80%) were extensive stage (ES) at the time of diagnosis. Fifty of the patients (80.6 Medical Oncology Clinic) were given median 5.36 cycles of cisplatin-etoposide (2-8 cycles). Time to recurrence was $15.6{\pm}6.13$ weeks in patients with limited stage (LS) and $6.3{\pm}3.82$ weeks in extensive stage (ES) (p<0.0001). Overall survival was $14.0{\pm}6.08$ months in ES and $17.9{\pm}6.88$ months in LS. The difference between two groups was statistically meaningful (p=0.0447). The overall survival of the patients was $14.8{\pm}6.43$ months (4.5-40 months). In terms of survival, there was no difference between males and females (p=0.1171). In 17 (27%) patients who were refractory to topotecan or in whom progression occurred other chemotherapies were used. Conclusion: Small cell lung cancer is chemosensitive, but recurrences occur in short time. Other chemotherapy regimens are used in progression. Topotecan is one of them. Patients who were young and in whom recurrences occur late had given better response to topotecan. Because of the retrospective nature of the study, we couldn't reach the records exactly and consequently, rate and duration of response couldn't be calculated. In recurrent SCLC topotecan is one of the treatment choices. But both hematological and non hematological side effects should be taken into consideration.

• Journal of Korean Academy of Nursing
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• v.15 no.3
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• pp.5-20
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• 1985

The purpose of this study was to assess the value-of post-operative treatment in terms of nursing care in the allevation of pain. More specifically, the effects of supportive touch and patient education were examined. On the date before each patient's operation, the Bevels of anxiety, depression and affiliation were examined. The post-operative treatment was adminis. tered after an initial measurement of the patient's fain, according to the experimental category for the three days following the operation. On the final day, the level of anxiety and depression were again measured. The subjects of this study were 138 patient from the general surgical and gynecological wards in H university Hospital in Seoul. The study was conducted over a three-month period from June 24, 1984 to September 18, 1984. All patients had undergone laparatomies. Various standard instruments were used to measure the pain, anxiety, depression and affiliation levels. for pain, 5 grate Simple Descriptive Scale, and the Mclachlan four-range Observational Pain Scale were employed. For anxiety and depression, respectively the Spielberger State Anxiety Inventory and Beck Depression Inventory (B.D.I.) were used. Lastly, the affiliation was determined by the Mehrabian Affiliation Scale. The outcome of the research was as follows: 1. The first hypothesis concerning the existence of lower pain levels of Experimental Group A and Experimental Group B than the pain levels of Control Croup C was not supported. 2. The second hypothesis concerning the existence if lower anxiety levels of Experimental Group A and Experimental Group B than the anxiety levels of Control Group C was supported at the level of F=3.58 (p=.03). 3. The third hypothesis concerning the existence of lower depression levels of Experimental Group A and Experimental Group B than the depression levels of Control Group C was not supported. 4. The fourth hypothesis concerning the existence of different levels of pain in accordance with the levels of affiliation in Experimental Group A was not supported. 5. A positive correlation did exist between pain and anxiety after surgery (r=.34, p=.0001). Thus, the fifth hypothesis was supported. 6. A positive correlation did exist between pain and depression following surgery(r=.36, p=.0001). Thus, the sixth hypothesis was supported. Based on the above results, it was found that supportive touch and patient education either through human sources or via tape recorder do influence the anxiety of a patient after surgery, that a Positive correlation between pain, anxiety and deparession exist, that affiliation does not alter the influence of supportive touch, and that the graph on which pain levels were depicted indicates the possibility of development even if the effects of supportive touch did not reach a meaningful level. Thus it can be concluded that patient education, regardless of its form, is essential for the patient after surgery and that supportive touch, when reasonably modified and supplemented, can be an effective method of alleviating pain.

• Journal of Korean Clinical Health Science
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• v.2 no.4
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• pp.231-238
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• 2014

Purpose. This study examines the effects of improving students self-esteem and sociability by conducting a Group Art Therapy Program for students with learning disabilities. This study focused on three students with learning disabilities, attending B middle school special education class located in K county. The study was conducted for two hours once a week (Friday) at B middle school during special education class from May 2, 2014 to July 18, 2014. Methods. For the tools of studying, Self-esteem and social strip forms/rubrics were filled, by students', before and after and data processing was inspected, paired t-Test using the SPSS / WIN (Ver.18.0) for quantitative analysis. Also, on the basis of content, analyzed data of the individuals' self-esteem social changes are shown in graph format. In addition, this qualitative study shows before and after of dynamic house, tree, person (K-H, T, P), dynamic family (KFD), dynamic school life of search phase (4-6 sessions) significant improvement of self-esteem and sociability in adolescents' with learning disabilities influenced by conducting a Group Art Therapy Program. Results. The result of this study can be summarized as follows. First, Group Art Therapy Program shows a statistically significant difference (p<.05) showing that self esteem average is 2.04 before Group Art Therapy Intervention but self esteem average is 2.92 after Group Art Therapy Intervention. Second, as a result of social strip pre-post, there wasn't statistically significant difference compared to self esteem pre-post result, although, post examination's average level was enhanced after Group Art Therapy Program in difference examination.(p>.05). Third, as a result of analysis the indicated pre-post change of Students' pre-post dynamic house, tree, person (HTP), dynamic family (KFD), a dynamic school daily life (KSD), students' family and interpersonal relationships, self-concept shows statistical significant changes. Conclusion. As the result of this study, Group Art Therapy Program shows effective improvement in students' self-esteem and social skills learning disabilities. However, a future study on larger and more diverse group of students' with learning disabilities are advised to be conducted in order to better understand the significance of the Group Art Therapy Program.

• Korean Journal of Radiology
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• v.23 no.10
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• pp.986-997
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• 2022

Objective: Whether metabolic redistribution occurs in patients with white matter hyperintensities (WMHs) on magnetic resonance imaging (MRI) is unknown. This study aimed 1) to propose a measure of the brain metabolic network for an individual patient and preliminarily apply it to identify impaired metabolic networks in patients with WMHs, and 2) to explore the clinical and imaging features of metabolic redistribution in patients with WMHs. Materials and Methods: This study included 50 patients with WMHs and 70 healthy controls (HCs) who underwent ¹⁸F-fluorodeoxyglucose-positron emission tomography/MRI. Various global property parameters according to graph theory and an individual parameter of brain metabolic network called "individual contribution index" were obtained. Parameter values were compared between the WMH and HC groups. The performance of the parameters in discriminating between the two groups was assessed using the area under the receiver operating characteristic curve (AUC). The correlation between the individual contribution index and Fazekas score was assessed, and the interaction between age and individual contribution index was determined. A generalized linear model was fitted with the individual contribution index as the dependent variable and the mean standardized uptake value (SUV_mean) of nodes in the whole-brain network or seven classic functional networks as independent variables to determine their association. Results: The means ± standard deviations of the individual contribution index were (0.697 ± 10.9) × 10^-3 and (0.0967 ± 0.0545) × 10^-3 in the WMH and HC groups, respectively (p < 0.001). The AUC of the individual contribution index was 0.864 (95% confidence interval, 0.785-0.943). A positive correlation was identified between the individual contribution index and the Fazekas scores in patients with WMHs (r = 0.57, p < 0.001). Age and individual contribution index demonstrated a significant interaction effect on the Fazekas score. A significant direct association was observed between the individual contribution index and the SUV_mean of the limbic network (p < 0.001). Conclusion: The individual contribution index may demonstrate the redistribution of the brain metabolic network in patients with WMHs.

• Journal of the Korean Chemical Society
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• v.58 no.3
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• pp.283-288
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• 2014

A column solid phase extraction procedure based on modified polyurethane foam (PUF) by a newly synthesized Schiff base ionophore, named 2,2'-{iminobis[propane-3,1-diylnitrilo(1E)prop-1-yl-1-ylidene]}diphenol, was developed for preconcentration step of trace amounts determination of copper ions in water samples by atomic absorption flame spectroscopy. The influence of parameters on the adsorption process such as sample pH, amount of modified PUF packed in the column, type and volume of stripping reagent and its flow rate were investigated and optimized. Under optimum experimental conditions, the calibration graph was linear in a relatively wide range ($0.005-210{\mu}g/ml$) with a limit of detection $0.002{\mu}g/ml$ of copper. The proposed method allows achieving to a concentration factor of >133. The capacity of a column (1.6 cm i.d.) packed by 6 g of PUF modified by 12 mg of the Schiff base was found to be $247.7({\pm}2.1){\mu}g$ of copper. It was found that the adsorption process was highly selective towards copper ions with respect to some associated metal ions. The presented procedure was successfully applied for determination of copper in some water samples.

• Journal of the Korean Society of Safety
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• v.30 no.4
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• pp.26-31
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• 2015

The purpose of this paper is to measure the induced voltage of the downscaled and simulated overhead ground wire of a 22.9kV-Y distribution line. This study performed a test of the downscaled and simulated distribution line according to whether it is grounded or not and the value of the ground resistance. In order to verify the reliability of the data measured by the test, the data was analyzed using the Minitab 17 program. It was found that the induced voltage of the downscaled and simulated distribution line is influenced by the value of the ground resistance. It was also found that the ground resistance obtained at a certain point is closely related to whether electric poles are grounded or not. The analysis results of the measured test data with a statistical method showed that the Anderson Darling (AD) was analyzed to be the smallest as 0.188 when the ground resistance of the electric poles had been maintained at $10{\Omega}$. In addition, the P value analyzed to be 0.894 which is in the proximity of the theoretical value of 1 and verified the reliability of the test data. It could be seen that the data measured by the downscaled simulation test forms a linear graph. It is thought that if a distribution line is installed in the same manner as the downscaled, simulated distribution line, the mean induced voltage will be reduced and reliability will be increased.