• Title/Summary/Keyword: p-center problem

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Extraction of optimal time-varying mean of non-stationary wind speeds based on empirical mode decomposition

  • Cai, Kang;Li, Xiao;Zhi, Lun-hai;Han, Xu-liang
    • Structural Engineering and Mechanics
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    • v.77 no.3
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    • pp.355-368
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    • 2021
  • The time-varying mean (TVM) component of non-stationary wind speeds is commonly extracted utilizing empirical mode decomposition (EMD) in practice, whereas the accuracy of the extracted TVM is difficult to be quantified. To deal with this problem, this paper proposes an approach to identify and extract the optimal TVM from several TVM results obtained by the EMD. It is suggested that the optimal TVM of a 10-min time history of wind speeds should meet both the following conditions: (1) the probability density function (PDF) of fluctuating wind component agrees well with the modified Gaussian function (MGF). At this stage, a coefficient p is newly defined as an evaluation index to quantify the correlation between PDF and MGF. The smaller the p is, the better the derived TVM is; (2) the number of local maxima of obtained optimal TVM within a 10-min time interval is less than 6. The proposed approach is validated by a numerical example, and it is also adopted to extract the optimal TVM from the field measurement records of wind speeds collected during a sandstorm event.

Effects of a Cognitive Behavioral Stress Management Program on Perceived Stress, Coping Strategies, and Stress Response in People with Diabetes Mellitus Type 2 (인지행동기반 스트레스관리 프로그램이 제2형 당뇨병 환자의 스트레스, 대처 및 스트레스 반응에 미치는 효과)

  • Park, Hyoung-Sook;Park, Kyung-Yeon
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.15 no.3
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    • pp.291-300
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    • 2008
  • Purpose: The purpose of this study was to identify the effects of a cognitive behavioral stress management program on perceived stress, coping strategies, and cortisol in people with Diabetes Mellitus Type 2. Method: Patients with type 2 diabetes were recruited from of a public health center in an urban area. Thirty-five participants (experimental group=17, and control group=18) enrolled. The experimental group received small group-based cognitive behavioral stress management training for eighty minutes per session, once a week for eight weeks. Data were collected at baseline and ninth week for perceived stress, affect-oriented coping, problem-oriented coping, and cortisol. The data were analyzed using SPSS 12.0. Results: The experimental group had significantly less perceived stress (t=-9.82, P<.001) and cortisol (t=-2.14, p=.040) than the control group. No significant group differences were found in affect-oriented coping (t=-.43, p=.673) or problem-oriented coping (t=1.40, P<.170). Conclusion: These results suggest that a cognitive behavioral stress management program can have positive effects on perceived stress and cortisol in patients with diabetes mellitus type 2. Further research with a larger sample and for a longer period is needed to expand our understanding of the effects of the program for patients with diabetes mellitus type 2.

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Predictive Factors Affected to Forced Vital Capacity in Children with Cerebral Palsy (뇌성마비 아동에서 노력성 폐활량에 영향을 미치는 요인 분석에 관한 연구)

  • Nam, Ki Seok;Lee, Hye Young
    • The Journal of Korean Physical Therapy
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    • v.25 no.4
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    • pp.204-209
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    • 2013
  • Purpose: Children with cerebral palsy generally have a high incidence of respiratory problem, resulted from poor coughing, airway clearance problem, respiratory muscle weakness, kyphoscoliosis and so forth. The purpose of this study is to investigate the possible factors that can be affected to forced vital capacity (FVC) in children with cerebral palsy. Methods: Total thirty six children with diplegic and hemiplegic cerebral palsy were recruited in this study. They were evaluated by general demographic data (i.e., age, gender, body mass index (BMI)) and variables related to respiratory functions (i.e., chest mobility, waist mobility, maximal phonation time, and maximum inspiratory/expiratory pressure (MIP/MEP)). The correlation between forced vital capacity and the rested variables were analyzed, and multiple regression with stepwise method was conducted to predict respiratory function, in terms of FVC as the dependent variable, and demographic and other respiratory variables as the independent variable. Results: FVC showed a significant correlation with waist mobility (r=0.59, p<0.01), maximal phonation time (r=0.48, p<0.05), MIP (r=0.73, p<0.01), and MEP (r=0.60, p<0.01). In addition, the multiple regression analysis model indicated that FVC could be predicted by the assessment of each waist mobility and MIP. Conclusion: These finding suggest that respiratory function is related to body size and respiratory muscle strength, and that BMI, waist mobility, and MIP can be predictable factors to affected respiratory function in term of FVC.

Development of a Pain Assessment Tool for Critically Ill Patients (중환자 통증사정 도구 개발)

  • Choi, Eun Hee;Kim, Jin Hee;Choi, Kyung Ok;Yoo, Jung Sook;Kim, Mi Soon;Kim, Pil Ja;Jang, In Sun
    • Journal of Korean Clinical Nursing Research
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    • v.18 no.1
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    • pp.136-148
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    • 2012
  • Purpose: The purpose of this study was to develop a reliable and valid pain assessment tool suitable for critically ill patients with communication problem in Korean intensive care unit. Methods: This pain assessment tool, Critical Care Non-verbal Pain Scale (CNPS), was developed based on review of national and international researches. Data were collected from ten intensive care units at five major general hospitals in Seoul. Reliability and validity were tested during performance of position change and endotracheal suctioning. Pain was measured before, during, and 20 minutes after the two procedures. Results: Interrater reliability of the CNPS was analyzed by ICC (Intraclass correlation coefficients). ICC values were significant from .833 to .883. Significant correlation between the FPS (Face Pain Scale) scores and the CNPS scores verified concurrent validity of the CNPS. For position change, CNPS scores increased significantly between before and during (t=-23.399, p<.001) and decreased significantly between during and 20 minutes after (t=22.760, p<.001). For endotracheal suctioning, CNPS scores increased significantly between before and during (t=-29.064, p<.001) and significantly decreased between during and 20 minutes after (t=28.194, p<.001), verifying construct validity of the CNPS. Conclusion: Results indicate that the CNPS can be used to assess pain of critically ill patients who have communication problem.

Effects of Screen Time on Problematic Behavior in Children During the COVID-19 Pandemic in South Korea

  • Iyeon Kim;Sangha Lee;Su-Jin Yang;Donghee Kim;Hyojin Kim;Yunmi Shin
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.34 no.3
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    • pp.175-180
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    • 2023
  • Objectives: The coronavirus disease 2019 (COVID-19) pandemic has led to a decrease in face-to-face classes worldwide, affecting the mental health of children and their parents. The global pandemic has increased children's overall use of electronic media. This study analyzed the effect of children's screen time on problematic behaviors during the COVID-19 pandemic. Methods: A total of 186 parents from Suwon, South Korea, were recruited to participate in an online survey. The mean age of the children was 10.14 years old, and 44.1% were females. The questionnaire included questions on children's screen time, problematic behaviors, and parental stress. Children's behavioral problems were evaluated using the Behavior Problem Index, whereas the Parental Stress Scale was used to estimate parental stress. Results: The mean smartphone usage frequency of the children was 5.35 days per week, and the mean smartphone screen time was 3.52 hours per day. Smartphone screen time (Z=4.49, p<0.001) and usage frequency (Z=2.75, p=0.006) were significantly correlated with children's behavioral problem scores. The indirect effect of parental stress on this relationship was also statistically significant (p=0.049, p=0.045, respectively). Conclusion: This study suggests that children's smartphone screen time has affected problematic behaviors during the COVID-19 pandemic. Furthermore, parental stress is related to the relationship between children's screen time and problematic behaviors.

The Change of Muscle Strength, Muscle Endurance, Flexibility and Activities of Daily Living of the Kidney Transplant Recipients (신장이식 환자의 근력, 근지구력, 유연성 및 일상생활활동의 변화)

  • Ahn, Jae Hyun;Ha, Hee Sun;Hong, Jeong Ja
    • Korean Journal of Adult Nursing
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    • v.13 no.1
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    • pp.5-14
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    • 2001
  • The purpose of this study was to explore the change of muscle strength, muscle endurance, flexibility and activities of daily living to develop a rehabilitational program. The subjects were selected randomly among the patients who underwent kidney transplantations at one major transplantation hospital in Seoul, Korea. This study was carried out between November 23, 1999 and February 15, 2000. The subjects in this study consisted of 16 patients who had kidney transplantations between 1 month and 12 months ago prior to this study. They were all on steroids and did not take any physical exercise regularly. The muscle strength, muscle endurance, flexibility and activities of daily living were evaluated at 1st week and after 12 weeks. The data were analyzed with numbers, percentiles, mean, standard deviation and t-test. The results were as follows: 1. After 12 weeks, the grip strength was significantly decreased than 1st week (p=.0002). 2. After 12 weeks, the back lift strength was significantly decreased than 1st week (p=.0002). 3. After 12 weeks, the muscle endurance was increased than 1st week, but it was not significant(p=.5487). 4. After 12 weeks, the flexibility was significantly decreased than 1st week (p=.0002). 5. After 12 weeks, the activities of daily living was significantly decreased than 1st week (p=.0006). Like the above result, the kidney transplant receipients' muscle strength, flexibility and activities of daily living were reduced. In order to solve this problem, the writer has found that program development to prevent the defects should be extremely required. Since now on the number of patients should expand. After the kidney transplantation, the periods of 4, 8, 12 and 16 weeks are extended. The writer proposes to examine the different phase of change in each periods.

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Assessment of Problem Based Learning Application in Clinical Pharmacy Education (임상약학 교육에서의 문제중심학습 수업 방법 적용 평가)

  • Kim, Jung Tae;Kim, Jong Yoon;Kim, Myung Chun;Rhew, Ki Yon
    • Korean Journal of Clinical Pharmacy
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    • v.23 no.1
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    • pp.65-70
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    • 2013
  • Background: Colleges of Pharmacy in Korea have increased the number of years required for the degree from 4 years to 6 years in 2009. These changes are demanding revolution of education in pharmacology. The center of gravity is moving from medicine to application, theory to work. Problem-Based Learning is "learn to learn" working cooperatively in groups to seek solutions to real problems. PBL process cheers students to think critically to find optimal solution using appropriate learning resources. Method: Eighteen students in college of pharmacy are selected to participate in PBL lecture and take part in the survey about the effect of PBL in clinical pharmacy education. Results: General satisfaction score was high as four on a five-point scale, and students have improved on anxious about communication since the PBL classes compared to before of the lecture (P=0.037). Conclusion: PBL could be applied in clinical pharmacy education to progress student's participation and satisfaction. In addition this is improved communication skill in medical team during pharmacy practice.

Insufficient Sleep and Visuospatial Memory Decline during Adolescence (청소년기 수면 부족과 시공간 기억력 저하)

  • Lee, Chang Woo;Jeon, Sehyun;Cho, Seong-Jin;Kim, Seog Ju
    • Sleep Medicine and Psychophysiology
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    • v.26 no.1
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    • pp.16-22
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    • 2019
  • Objectives: The objective of this study was to investigate the correlation between insufficient sleep and visuospatial memory in adolescents using a computerized neurocognitive function test. Methods: A total of 103 high school students (26 males and 77 females; mean age $17.11{\pm}8.50years$) without a serious psychiatric problem was recruited. All subjects were requested to complete a self-report questionnaire about weekday total sleep time and weekend total sleep time. The epworth sleepiness scale (ESS) and the beck depression inventory (BDI) were administered to measure daytime sleepiness and symptoms of depression. Seven subsets of the Cambridge Neuropsychological test automated battery were examined to assess visuospatial memory. Results: After controlling for age, sex, ESS, and BDI, longer weekend total sleep time was correlated with poor performance on delayed matching to sample (r = -0.312, p = 0.002) and immediate recall on pattern recognition memory (r = -0.225, p = 0.025). Increased weekend catch-up sleep time was correlated with poor performance of delayed matching to sample (r = -0.236, p = 0.018), immediate recall on pattern recognition memory (r = -0.220, p = 0.029), and delayed recall on pattern recognition memory (r = -0.211, p = 0.036) after controlling for age, sex, ESS, and BDI. Conclusion: This study showed that increased weekend catch-up sleep time reflecting insufficient weekday sleep were associated with poor performance in delayed recall tasks of visual memory. This finding suggests that insufficient sleep during adolescence might produce a decline of visuospatial memory.

The Effects of Social Skills Training as a Preventive Approach for Children in the Community Setting (지역사회에서 예방적 접근으로 실시한 사회기술훈련의 효과)

  • Yoon, Seok Min;Kwack, Young Sook
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.25 no.3
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    • pp.128-135
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    • 2014
  • Objectives : The purpose of this study was to evaluate the effect of social skills training (SST) for children in two different community settings, an elementary school and a child community center. Methods : Two separate groups of 15 children (10 boys and 5 girls) and 13 children (4 boys and 9 girls) participated in a SST program twice per week at an elementary school and a child community center, respectively. Age range of participants was from 8 to 10 years. Sixty-minute-long sessions of SST were continued twice per week for 4 weeks. Korean-Child Behavior Checklist (K-CBCL), Conner's Rating Scales, Korean-Attention-Deficit Hyperactivity Disorder Rating Scale (K-ARS), Social Skills Rating System (SSRS), and Matson's Evaluation of Social Skills with Youngsters (MESSY) were evaluated by their parents before and after the SST program. Results : Pre-and-post analysis of SST indicated no significant statistical differences in the elementary school group. However, the child community center group showed significantly increased scores for total social ability (p<.05) and decreased scores for attention problem (p<.05) on the K-CBCL. In addition, scores of MESSY were significantly increased (p<.05). These differences between the two groups were still significant after controlling pre-SST scores ; and difference of SST scores between the two groups disappeared after SST. Conclusion : Results suggest that SST in the community setting is an effective tool for prevention of social deficits and problems in attention by promoting social function and attention.

A Novel Nicotinamide Adenine Dinucleotide Correction Method for Mitochondrial Ca2+ Measurement with FURA-2-FF in Single Permeabilized Ventricular Myocytes of Rat

  • Lee, Jeong Hoon;Ha, Jeong Mi;Leem, Chae Hun
    • The Korean Journal of Physiology and Pharmacology
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    • v.19 no.4
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    • pp.373-382
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    • 2015
  • Fura-2 analogs are ratiometric fluoroprobes that are widely used for the quantitative measurement of [$Ca^{2+}$]. However, the dye usage is intrinsically limited, as the dyes require ultraviolet (UV) excitation, which can also generate great interference, mainly from nicotinamide adenine dinucleotide (NADH) autofluorescence. Specifically, this limitation causes serious problems for the quantitative measurement of mitochondrial [$Ca^{2+}$], as no available ratiometric dyes are excited in the visible range. Thus, NADH interference cannot be avoided during quantitative measurement of [$Ca^{2+}$] because the majority of NADH is located in the mitochondria. The emission intensity ratio of two different excitation wavelengths must be constant when the fluorescent dye concentration is the same. In accordance with this principle, we developed a novel online method that corrected NADH and Fura-2-FF interference. We simultaneously measured multiple parameters, including NADH, [$Ca^{2+}$], and pH/mitochondrial membrane potential; Fura-2-FF for mitochondrial [$Ca^{2+}$] and TMRE for ${\Psi}_m$ or carboxy-SNARF-1 for pH were used. With this novel method, we found that the resting mitochondrial [$Ca^{2+}$] concentration was $1.03{\mu}M$. This $1{\mu}M$ cytosolic $Ca^{2+}$ could theoretically increase to more than 100 mM in mitochondria. However, the mitochondrial [$Ca^{2+}$] increase was limited to ${\sim}30{\mu}M$ in the presence of $1{\mu}M$ cytosolic $Ca^{2+}$. Our method solved the problem of NADH signal contamination during the use of Fura-2 analogs, and therefore the method may be useful when NADH interference is expected.