• Title/Summary/Keyword: Z-R Relationship

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Bioelectrical Impedance Analysis at Inner Forearms of the Human Body using Bioelectrical Impedance Measurement System

  • Kim, Jae-Hyung;Kim, Soo-Hong;Baik, Sung-Wan;Jeon, Gye-Rok
    • Journal of Korea Multimedia Society
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    • v.19 no.7
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    • pp.1146-1153
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    • 2016
  • The bioelectrical impedance (BI) at the inner forearms was measured using bioelectrical impedance measurement system (BIMS), which employs the multi-frequency and the two-electrode method. Experiments were performed as follows. First, while applying a constant alternating current of 800A to the inner region of the forearms, BI (Z) was measured at nineteen frequencies ranging from 5 to 500 kHz. The prediction marker (PM) was calculated for right and left forearm. The resistance (R) and the reactance (Xc) were simultaneously measured during impedance measurement. Second, a Cole-Cole plot (relationship between reactance and resistance) was obtained for left and right forearm, indicating the different characteristic frequencies (fc). Third, the phase angle was obtained, indicating strong dependence on the applied frequency.

Spatio-Temporal Changes and Drivers of Deforestation and Forest Degradation in North Korea (북한 산림의 시·공간 변화와 황폐화 추동)

  • Yu, Jaeshim;Kim, Kyoungmin
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.6
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    • pp.73-83
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    • 2015
  • The objective of this study is to establish implications for forest restoration planning in North Korea by analyzing spatio-temporal forest changes and detecting bio-physical factors driving forest degraded. We measured the relationship and spatial distribution between shifting cultivation and sparse forest. We also analyzed between degraded forest land and ecological variables by binary logistic regression to find biophysical drivers of forest degradation and deforestation in North Korea. Between the sparse forest and the shifting cultivation, a positive relationship is found (r=0.91) and scattered discontinuously throughout the country (Moran's I = -1, Z score = -13.46 (p=0.000)). The sparse forest showed a negative relationship with the warmest month(bio 9), the coldest month(bio10), and the minimum of soil water contents (swc_min), while the shifting cultivation had a negative relationship with the warmest month(bio 9) and the minimum of soil water contents(swc_min). However, the most critical drivers convert forests into sloping farmland were the three months rainfall in summer(bio8) and the yearly mean of soil water contents. Such results reflect the growth period of crops which overlaps with the rainy season in North Korea and the recent land reclamation of uplands where the soil water contents are maintained with a dense forest. When South Korea aids forest restoration projects in North Korea, in consideration of food shortage due to North Korea's cropland deficiency, terrace farmlands where soil water contents can be maintained should be excluded from the priority restoration area. In addition, an evaluation method for selecting a potential restoration area must be modified and applied based on multiple criteria including altitude and socio-economic factors in the respective regions.

Chemotherapy-related Cognitive Impairment and Quality of Life in People with Colon Cancer: The Mediating Effect of Psychological Distress (대장암 환자의 항암화학요법 관련 인지손상과 삶의 질: 심리적 디스트레스(우울·불안)의 매개효과)

  • Oh, Pok Ja;Kim, Jeong Hye
    • Journal of Korean Academy of Nursing
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    • v.46 no.1
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    • pp.19-28
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    • 2016
  • Purpose: The purpose of this study was to test the mediating effect of psychological distress in the relationship between chemotherapy related cognitive impairment (CRCI) and quality of life (QOL) in people with cancer. Methods: A purposive sample of 130 patients undergoing chemotherapy was recruited for the cross-sectional survey design. Data were collected from November 2014 to June 2015. The instruments were K-MMSE (Korean Mini-Mental State Examination), Everyday Cognition (ECog), Hospital Anxiety Depression Scale (HADS), and Functional Assessment of Cancer Therapy-General (FACT-G). Data were analyzed using descriptive statistics, correlation, and multiple regression using Baron and Kenny steps for mediation. Results: The mean score for objective cognitive function was 27.95 and 69.32 for perceived cognitive decline. Overall quality of life was 91.74. The mean score was 17.52 for psychological distress. The prevalence was 56.2% for anxiety and 63.1% for depression, and 20.0% for CRCI. There were significant correlations among the variables, objective cognitive function and self-reported cognitive decline, psychological distress, and quality of life. Psychological distress was directly affected by CRCI. ($R^2=29%$). QOL was directly affected by CRCI. Psychological distress and CRCI effected QOL ($R^2=43%$). Psychological distress had a partial mediating effect (${\beta}=-.56$, p <.001) in the relationship between self-reported cognitive decline and quality of life (Sobel test: Z= -5.08, p <.001). Conclusion: Based on the findings of this study, nursing intervention programs focusing on managing cognitive decline, and decreasing psychological distress are highly recommended to improve quality of life in cancer patients.

Seasonal Variation of Water Quality in a Shallow Eutrophic Reservoir (얕은 부영양 저수지의 육수학적 특성-계절에 따른 수질변화)

  • Kim, Ho-Sub;Hwang, Soon-Jin
    • Korean Journal of Ecology and Environment
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    • v.37 no.2 s.107
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    • pp.180-192
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    • 2004
  • This study was carried out to assess the seasonal variation of water quality and the effect of pollutant loading from watershed in a shallow eutrophic reservoir (Shingu reservoir) from November 2002 to February 2004, Stable thermocline which was greater than $1^{\circ}C$ per meter of the water depth formed in May, and low DO concentration (< 2 mg $O_2\;L^{-1}$) was observed in the hypolimnion from May to September, 2003. The ratio of euphotic depth to mixing depth ($Z_{eu}/Z_{m}$) ranged 0.2 ${\sim}$ 1.1, and the depth of the mixed layer exceeded that of the photic layer during study period, except for May when $Z_{eu}$ and $Z_{m}$ were 4 and 4.3 m, respectively. Most of total nitrogen, ranged 1.1 ${\sim}$ 4.5 ${\mu}g\;N\;L^{-1}$, accounted for inorganic nitrogen (Avg, 58.7%), and sharp increase of $NH_3$-N Hand $NO_3$-N was evident during the spring season. TP concentration in the water column ranged 43.9 ${\sim}$ 126.5 ${\mu}g\;P\;L^{-1}$, and the most of TP in the water column accounted for POP (Avg. 80%). During the study period, DIP concentration in the water column was &;lt 10 ${\mu}g\;P\;L^{-1}$ except for July and August when DIP concentration in the hypolimnion was 22.3 and 56.7 ${\mu}g\;P\;L^{-1}$, respectively. Increase of Chl. a concentration observed in July (99 ${\mu}g\;L^{-1}$) and November 2003 (109 ${\mu}g\;L^{-1}$) when P loading through two inflows was high, and showed close relationship with TP concentration (r = 0.55, P< 0.008, n = 22). Mean Chl. a concentration ranged from 13.5 to 84.5 mg $L^{-1}$ in the water column, and the lowest and highest concentration was observed in February 2004 (13.5 ${\pm}$ 1.0 ${\mu}g\;L^{-1}$) and November 2003 (84.5 ${\pm}$29.0 ${\mu}g\;L^{-1}$), respectively. TP concentration in inflow water increased with discharge (r = 0.69, P< 0.001), 40.5% of annual total P loading introduced in 25 July when there was heavy rainfall. Annual total P loading from watershed was 159.0 kg P $yr^{-1}$, and that of DIP loading was 126.3 kg P $yr^{-1}$ (77.7% of TP loading. The loading of TN (5.0ton yr-1) was 30 times higher than that of TP loading (159.0 kg P yr-1), and the 78% of TN was in the form of non-organic nitrogen, 3.9 ton $yr^{-1}$ in mass. P loading in Shingu reservoir was 1.6 g ${\cdot}$ $m^{-2}$ ${\cdot}$ $yr^{-1}$, which passed the excessive critical loading of Vollenweider-OECD critical loading model. The results of this study indicated that P loading from watershed was the major factor to cause eutrophication and temporal variation of water quality in Shingu reservoir Decrease by 71% in TP loading (159 kg $yr^{-1}$) is necessary for the improvement of mesotrophic level. The management of sediment where tine anaerobic condition was evident in summer, thus, the possibility of P release that can be utilized by existing algae, may also be considered.

The Effect of Social Support of the Elderly Using Elderly Welfare Center on Suicidal Ideation through the Mediating Effect of Avoidance Coping Style (복지관 이용 노인의 사회적 지지가 회피적 대처방식의 매개효과를 통하여 자살생각에 미치는 영향)

  • Chang, Koung-Oh
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.6
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    • pp.226-236
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    • 2021
  • The purpose of this study was to investigate the effect of social support on suicidal ideation among the elderly at welfare centers through the mediating effect of avoidance coping style. This is a descriptive research survey of 392 elderly people at four elderly welfare centers located in G city. Data were collected from October 21 to November 8, 2019, and analyzed using the IBM SPSS/win 26.0 program by t-test, ANOVA, and the Pearson's correlation coefficient. The mediating effect was analyzed by multiple regression analysis according to Baron and Kenny's 3-step analysis procedure. Social support of the subjects was found to be high with an average score of 5.73±1.23, avoidance coping style with 12.53±3.47 points, and suicidal ideations with 6.21±2.06 points. In the correlation between the variables, suicidal ideations were negatively correlated with social support (r=-.146, p=.004) and avoidance coping style (r=.315, p<.001), and these correlations were statistically significant. There was a positive correlation. The avoidance coping style of the elderly using the welfare centers was found to partially mediate the relationship between social support and suicidal ideation (Z=-.270, p<.001). Therefore, to prevent negative emotions such as suicidal ideations in the elderly, various policies and support programs at the local and government level should be continuously implemented.

Improvement of Radar Rainfall Intensity and Real-time Estimation of Areal Rainfall (레이더에 의한 개선된 강우강도와 면적 강우량의 실시간 추정)

  • Jung, Sung-Hwa;Kim, Kyung-Eak;Kim, Gwang-Seob
    • Proceedings of the Korea Water Resources Association Conference
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    • 2006.05a
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    • pp.643-646
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    • 2006
  • An operational calibration is applied to improve radar rainfall intensity using rainfall obtained from rain gauge. The method is applied under the assumption of the temporal continuity of rainfall, the rainfall intensity from rain gauge is linearly related to that from radar. The method is applied to the cases of typhoon and rain band using the reflectivity of CAPPI at 1.5km obtained from Jindo radar. The CAPPI is obtained by bilinear interpolation. For the two cases, the rainfall intensities obtained by operational calibration are very consistent with the ones by the rain gauges. The present study shows that the correlation between the rainfall intensity by operational calibration and rain gauges is better than the one between the rainfall intensity by M-P relationship and rain gauges. The correlation coefficients between the total rainfall intensity obtained by operational calibration and rain gauges in typhoon and rain band cases are 0.99 and 0.97, respectively. Areal rainfalls are estimated using the field of calibration factor interpolated by Barnes objective analysis. The method applied here shows an improvement in the areal rainfall estimation. For the cases of typhoon and rain band, the correlation between the areal rainfall by operational calibration and rain gauges is better than the one between the area rainfall by M-P relationship and rain gauges. The correlation coefficients between the areal rainfall obtained by operational calibration and rain gauges in typhoon and rain band cases are 0.97 and 0.84, respectively. The present study suggests that the operational calibration is very useful for the real-time estimation of rainfall intensity and areal rainfall.

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DNA Repair Capacity in Peripheral Blood Lymphocytes Predicts Efficacy of Platinum-based Chemotherapy in Patients with Gastric Cancer

  • Zhang, Yi-Yin;Gu, Kang-Sheng
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.9
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    • pp.5507-5512
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    • 2013
  • Objective: To investigate the correlation between ERCC1 expression levels in tumor tissue and peripheral blood lymphocytes (PBL) from patients with gastric cancer and assess the relationship between PBL DNA repair rate (DRR) and the efficacy of platinum chemotherapy. Methods: A total of 53 patients with gastric cancer receiving surgery and 20 controls were studied. ERCC1 protein expression in tumour tissue and PBL were determined by immunohistochemical staining. The PBL DRRs of 47 advanced patients and 20 controls were estimated by comet assay. Results: The positive expression rates of ERCC1 were 67. 9%, 56. 6% and 10.0% in tumour tissues, PBLs of gastric cancer patients, and PBLs of the control group. PBL ERCC1 expression correlated with that in tissue (${\chi}^2$=15. 463, p=0.000). Pearson contingency coefficient=0.475). DRRs of cancer patients by tail length (TL) (Z=4. 662, p=0.000) and tail moment (TM) (Z=3. 827, p=0.000) were significantly lower than that of control group. When TL was applied as an indicator, the correlation between DRR and chemotherapy efficacy was significant (Spearman rank correlation r=0.327, p=0.032). Patients with low levels of DRR in PBL presented better short-term efficacy of chemotherapy than those with high levels of DRR. Conclusions: The ERCC1 expression in PBLs may indirectly reflect ERCC1 expression in gastric cancer tissues. Compared with non-cancer populations, patients with gastric cancer may have lower DNA repair capacity. DRR in PBL may predict the short-term efficacy of platinum-based chemotherapy for patients with advanced gastric cancer.

The Impact of Self-regulated Learning Ability on Learning Persistence Intention in Freshmen in Nursing College: Focusing on the Mediating Effects of Learning Motivation (간호대학 신입생의 자기조절학습능력이 학습지속의향에 미치는 영향: 학습동기의 매개효과를 중심으로)

  • Park, Ju Young;Woo, Chung Hee;Lee, Jung Hyuk;Kim, Jeong Min
    • The Journal of Korean Academic Society of Nursing Education
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    • v.24 no.2
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    • pp.127-136
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    • 2018
  • Purpose: The purpose of this study was to examine the effects of self-regulated learning ability of freshmen in nursing college on the learning persistence intention, and to determine if their learning motivation meditates the relationship between them. Methods: The study design was based on descriptive research. Data were collected from 146 nursing freshmen studying at a university in D city from June 5, 2017 to June 7, 2017. Results: There was a positive correlation among learning persistence intention, self-regulated learning ability (r=.57, p<.001) and learning motivation (r=.60, p<.001). Also, it was found that learning motivation was positively correlated with self-regulated learning ability (r=.79, p<.001). According to the Sobel test results, the learning motivation had a complete mediating effect (${\beta}=.39$, p<.001) between self-regulated learning ability and learning persistence intention (Z=3.63, p<.001). Conclusion: Therefore, this study suggests developing a learning motivation program to improve self-regulated learning ability and learning persistence intention of nursing students during their freshman year.

The mediating effect of task value between grit and academic stress on nursing students (간호대학생의 그릿과 학업스트레스와의 관계에서 과제가치의 매개효과)

  • Kang, Moon-Hee
    • Journal of Digital Convergence
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    • v.20 no.1
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    • pp.471-479
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    • 2022
  • The purpose of this study is to investigate the mediating effect of task value on the relationship between grit and academic stress in nursing students. Data collection was conducted through a mobile Google questionnaire from August 31, to September 9, 2021, and the subjects were a total of 192 nursing students from three universities. The data were analyzed using descriptive statistics, t-test, one-way ANOVA, Pearson's correlation coefficients, and multiple regression analysis with SPSS/WIN 20.0 program. The grit had statistically significant negative correlation with academic stress and positive correlation with task value, and task value and academic stress had positive correlation. Task value had a partial mediating effect on the between grit and academic stress. Thus intervention program that considers the task value along with the grit should be developed in order to alleviate the academic stress of nursing students.

Estimation of reflectivity-rainfall relationship parameters and uncertainty assessment for high resolution rainfall information (고해상도 강수정보 생산을 위한 레이더 반사도-강수량 관계식 매개변수 보정 및 불확실성 평가)

  • Kim, Tae-Jeong;Kim, Jang-Gyeong;Kim, Jin-Guk;Kwon, Hyun-Han
    • Journal of Korea Water Resources Association
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    • v.54 no.5
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    • pp.321-334
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    • 2021
  • A fixed reflectivity-rainfall relationship approach, such as the Marshall-Palmer relationship, for an entire year and different seasons, can be problematic in cases where the relationship varies spatially and temporally throughout a region. From this perspective, this study explores the use of long-term radar reflectivity for South Korea to obtain a nationwide calibrated Z-R relationship and the associated uncertainties within a Bayesian inference framework. A calibrated spatially structured pattern in the parameters exists, particularly for the wet season and parameter for the dry season. A pronounced region of high values during the wet and dry seasons may be partially associated with storm movements in that season. Overall, the radar rainfall fields based on the proposed modeling procedure are similar to the observed rainfall fields. In contrast, the radar rainfall fields obtained from the existing Marshall-Palmer relationship show a systematic underestimation. In the event of high impact weather, it is expected that the value of national radar resources can be improved by establishing an active watershed-level hydrological analysis system.