• Journal of Environmental Science International
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• v.26 no.10
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• pp.1147-1153
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• 2017

To maintain a rich biological diversity is important to develop for biomaterial resources such as Korean evergreen broad-leaved tree species, the distribution of which is restricted to the southern part of Korean peninsula. We assessed photosynthetic characteristics of Quercus acuta and Castanopsis sieboldii, the representative evergreen broad-leaved trees in Korea, in order to establish a basis for conservation strategy related to distributional change in evergreen broad-leaved tree species according to climate change. Photosynthetic characteristics were evaluated in the sun and shade leaves of the two species. Sun leaves in both species revealed higher light compensation point and maximum photosynthetic rate compared to the shade leaves. In addition, photosynthetic rate was higher in Q. acuta than C. sieboldii, which was supported by a higher leaf nitrogen content and leaf mass per area. Water use efficiency was also higher in Q. acuta as compared to that in C. sieboldii. Similar photosynthetic rate, however, was shown in photosynthetic response to $CO_2$ concentration in the intercellular space. These results suggest that both species could respond differently to the changing environmental factors including climate change, suggesting the possibility of distributional changes resulting from a differential growth rate.

• Journal of Climate Change Research
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• v.8 no.1
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• pp.63-71
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• 2017

It is recognized that tetrafluoromethane ($CF_4$) has a great influence on global warming. The $CF_4$ is known to have a large impact on climate change due to its large global warming index. In this study, a waterjet plasma scrubber (WPS) was designed and manufactured for the $CF_4$ decomposition. The WPS is a novel technology which is combined a gliding arc plasma and water injection at the center of the plasma discharge. This can give an innovative way for $CF_4$ decomposition by achieving larger plasma columnand generating OH radicals. A performance analysis was achieved for the design factors such as waterjet flow rate, total gas flow rate, consumption electric power, and electrode gap. The highest $CF_4$ decomposition and energy efficiencies were 64.8% and 6.43 g/kWh, respectively; Optimal operating conditions were 20 mL/min of waterjet flow rate, 200 L/min total gas flow rate, 5.3 kW consumption electric power, and 4.4 mm electrode gap. As for the 2 stage reactor of the WPS, the $CF_4$ decomposition efficiency improved as the 85.3% while the energy efficiency decreased as the 5.57 g/kWh.

• Research in Community and Public Health Nursing
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• v.6 no.1
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• pp.98-113
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• 1995

The purpose of this study were two fold : first, to determine the effect of aerobic exercise on BP, pulse rate, body fat, body weight, symptoms of sterss response: and secondly, to apply the aerobic exercise on nursing practice in the healthy or ill subjects. In an attempt to investigate the physiological and psychological effect of exercise, a quasi -experiment, non-equivalent control group pre-test & post-test design was planned. Experiments were carried out from July 4, through August 30, 1994 with 37 subjects conveniently sampled from K & Y sports center located in Taejon. The 37 research subjects were assigned to experimental(16 subjects) and control(21 subjects) groups. Aerobic exercise was carried out for experimental group from three times to five times a week for 6 weeks in aerobic center. Data were analyzed with t-test, mean, per centage of change using SAS program. Results were obtained as follows: 1) Systolic blood pressure (M=123.75mmHg, % of change=1.12%) and diastolic blood pressure (M=74.38mmHg, % of change=5.79%) was increased on that of experimental group after 6 weeks experiment. But there was no significant difference between experimental group and control group. 2) Body weight was decreased on that of experimental group(M=56.54Kg, % of change=-1.60%) and that of control group(M=52.05, % of change=-0.99%) after 6 weeks. But there was no significant difference between experimental group and control group. 3) Body fat was decreased on that of experimental group(M=30.53%, % of change=-3.60%) and that of control group (M=28.75%, % of change=-3.52%) after 6 weeks. There was no significant difference between experimental group and control group. 4) Pulse rate was decreased on that of experimental group(M=69.19회/min, % of change -8.43%) and that of control group(M=76.0회/min, % change -0.07%) after 6weeks. There was significant difference(t=-2.621, P<0.05) between experimental group and control group. 5) Symptoms of stress response were decreased on that of experimental group(M=0.97) and that of control group(M=1.15) after 6 weeks. There was no significant difference between experimental group and control group. Therefore, adherence to aerobic exercise for 6 week seem to be affected mainly pulse rate of subjects. A futher study is necessary to determine the difference in the effect of variety exercise, programs, to study over 6 weeks, to produce professional educational program for exercise speciality nurses.

• Conservation Science in Museum
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• v.3
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• pp.71-78
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• 2001

The airtightness of museum cases in museums was measured by using CO₂ tracing gas, but it has been pointed that it has a problem with measuring the airtightness of a museum case which has a hole inside before it is used or while is being used. So studies tried to come up with alternatives which make it possible to measure the airtightness of a museum case before it is used or while it is being used if necessary by indirectly measuring the airtightness of the museum case without changing its form. Indirect measuring is done by measuring the change of Art-sorb weight and the change of temperature and humidity inside the museum case. Experiments were made for 12 days with three builtin wall case installed at the same place without turning on the lights but with Art-sorb and the data logger of temperature and humidity put into museum case. The change rate was produced with the change of temperature and humidity inside the museum case divided by that of those around museum case. As a result, the temperature change rate of museum case A(0.67) was lower than that of museum case B(0.69) or museum case C(0.79). The humidity change rate of museum case A(0.12) was lower than that of museum case B(0.19) or museum case C(0.72) showing that its airtightness was the best. Also in the direct airtightness measurement by CO₂ tracing gas, the air exchange rate was compared with the humidity change rate by Art-sorb in the indirect measurement.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.26 no.6
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• pp.21-32
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• 2023

The Environmental Impact Assessment (EIA) plays a pivotal role in predicting the potential environmental impacts of proposed developments and planning appropriate mitigation measures to minimize effects on species. However, as concerns over biodiversity loss rise, there's ongoing debate about the efficacy of these mitigation plans. In this study, we utilized data from EIAs and post-environmental impact surveys to understand the trends in biodiversity during construction and operation phases. By examining 30 urban development projects, we categorized species richness indices of mammals, birds, amphibians, and reptiles into pre-construction, during construction, and post-construction operational stages. The biodiversity trends were analyzed based on the rate of change in these indices. The results revealed three distinct biodiversity change patterns: (A) An initial increase in biodiversity indices post-development, followed by a gradual decline over time; (B) a sustained increase in biodiversity as a result of mitigation measures; and (C) a continuous decline in biodiversity post-development. Furthermore, all species exhibited a higher rate of biodiversity decline during the construction phase compared to the operational phase, with mammals showing the most significant rate of change. Notably, the biodiversity change rate during operation was generally lower than during construction. In particular, mammals seemed to be most influenced by mitigation measures, displaying the smallest rate of change. This study provides empirical evidence on the efficacy of mitigation measures and deliberates on ways to enhance their effectiveness in minimizing the adverse impacts of urban development on biodiversity. These findings can serve as foundational data for addressing terrestrial biodiversity reduction.

• 한국데이터정보과학회:학술대회논문집
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• 2004.10a
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• pp.25-32
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• 2004

In this study, we use various change-point detection methods to detects Korea economic crisis of 1997, and then compares their performance. In change-point detection method, there are three major categories: (1) the parametric approach, (2) the nonparametric approach, and (3) the model-based approach. Through the application to Korea foreign exchange rate during her economic crisis, we compare the employed change-point detection methods and, furthermore, determine which of them performs better.

• Journal of the Korean Data and Information Science Society
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• v.15 no.3
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• pp.585-592
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• 2004

This study detects Korea economic crisis of 1997 using various change-point detection methods and then compares their performance. In change-point detection method, there are three major categories: (1) the parametric approach, (2) the nonparametric approach, and (3) the model-based approach. Through the application to Korea foreign exchange rate during her economic crisis, we compare the employed change-point detection methods and, furthermore, determine which of them performs better.

• Journal of Korean Biological Nursing Science
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• v.17 no.2
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• pp.114-122
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• 2015

Purpose: This study attempted to test whether there are differences in the level and hemodynamic side effects (blood pressure, heart rate, $O_2$ saturation), and nausea & vomiting of spinal anesthesia using hyperbaric bupivacaine according to position (supine, lateral, and prone positions) in orthopedic surgery patients who received podiatric surgery under spinal anesthesia. Methods: This study was conducted with 53 patients who had received orthopedic surgery under spinal anesthesia at I General Hospital. Data were analyzed using SPSS 20.0 through repeated-measures ANOVA, post-hoc test, Chi-test, and Fisher's exact test. Results: The change of position after spinal anesthesia with hyperbaric bupivacaine caused a change in the level of spinal anesthesia (F=12.768, p<.001). However, no difference of blood pressure, heart rate, $O_2$ saturation and nausea and vomiting caused by the change in anesthesia level was observed, and in prone position, drug was administered for the correction of side effects. Conclusion: As expected, recognizing that there can be a change in the level of spinal anesthesia after the change of position in surgical patients, nurse anesthetists should monitor their conditions carefully and continuously.

• Korean Journal of Chemical Engineering
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• v.35 no.11
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• pp.2321-2326
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• 2018

We evaluated the optimal conditions for fluidization of nickel oxide (NiO) and its reduction into high-purity Ni during hydrogen reduction in a laboratory-scale fluidized bed reactor. A comparative study was performed through structural shape analysis using scanning electron microscopy (SEM); variance in pressure drop, minimum fluidization velocity, terminal velocity, reduction rate, and mass loss were assessed at temperatures ranging from 400 to $600^{\circ}C$ and at 20, 40, and 60 min in reaction time. We estimated the sample weight with most active fluidization to be 200 g based on the bed diameter of the fluidized bed reactor and height of the stocked material. The optimal conditions for NiO hydrogen reduction were found to be height of sample H to the internal fluidized bed reactor diameter D was H/D=1, reaction temperature of $550^{\circ}C$, reaction time of 60 min, superficial gas velocity of 0.011 m/s, and pressure drop of 77 Pa during fluidization. We determined the best operating conditions for the NiO hydrogen reduction process based on these findings.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1021-1027
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• 1997

$CO_2$production in fermentation of dongchimi was measured and interrelated with changes in pH and titratable acidity. The effects of salt content and temperature on $CO_2$production rate were analysed. Fermentation of dongchimi showed drastic pH decrease in early stage and subsequent levelling off around 3.9, with linearly increased acidity up to 0.3~0.4% optimum quality. $CO_2$production of dongchimi could be analysed to consist of two consecutive stages of constant rate. The first stage $CO_2$production of higher rate moved to the second stage of lower rate when acidity rose beyond 0.3%. When compared to those of 1 and 2% salt content, dongchimi of 3% salt showed lower $CO_2$production rate in the 1st stage and slower acidity change through the whole fermentation period. However, it resulted in the product of highest $CO_2$accumulation at optimal ripeness because of consistent $CO_2$production of longer 1st stage period and relatively high $CO_2$production rate in 2nd stage. $CO_2$production depended on temperature less compared to acidity change(activation energy: 57.3 and 44.3kJ/mol for $CO_2$production of 1st and 2nd stages, respectively; 79.3kJ/mol for acidity change), which means higher ratio of $CO_2$production rate relative to acidity increase at lower temperature. Slower increase in acidity at low temperature also was shown to extend the period of 1st stage $CO_2$production. Therefore, low temperature fermentation was effective in producing the high $CO_2$content dongchimi at adequate acidity, which is desirable organoleptically.