• Journal of Plant Biology
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• v.28 no.2
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• pp.165-175
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• 1985

The natural forest vegetation of the Piagol, Mt. Chiri, was classified into five major communities, i.e. Quercus mongolica, Carpinus laxiflora, C. tschonoskii, Q. serrata and Fraxinus mandshurica community. C. tschonoskii, C. laxiflora and Q. mongolica characteristically were dominated in the range of 500∼700 m, 700∼900 m and 900∼1,400 m in altitude, respectively. Abies nephrolepis and Rhododendron schlippenbachii in the ridge of Nogodan-Nalnaribong, and F. mandshurica and Q. serrata in the Yongsuam ravine were found as the dominant species. The transition between C. tschonoskii and C. laxiflora communities was relatively wide. The boundary between F. mandshurica, in the conglomerated zone, and the other communities surrounding its community was fairly abrupt. In Q. mongolica community, the canopy was relatively opened and the oak young tree of undergrowth was fairly dense. In the community of C. laxiflora and C. tschonoskii, the species composed of their understory was rich while their coverage was lower than that of Q. mongolica community. Shannon's diversity index was decreased in order of C. tschonoskii, C. laxiflora and Q. mongolica community, while their Simpson's dominance index increased conversely. Judging by the DBH-class distribution showing the negative exponential curve, these communities were considered as the climax forest. In Polar Ordination used samples (quadrats), the vegetation of the Piagol was divided into five groups, which was coincided with five communities classified by Braun-Blanquet system. In the ordination, the first axis and the second axis may be considered soil conditions and thermal conditions, respectively. It seems that two different methods, phytosociological method in macro level and ordination techniques in micro level, are useful for the vegetation classification.

• Journal of the Korean Chemical Society
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• v.55 no.5
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• pp.733-740
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• 2011

Multiple regression analysis was used for the calculation of pKa values of 15 substituted benzaldoximes by using various types of descriptors as parameters. These descriptors are based on quantum mechanical treatments. They were derived by employing semi-empirical calculation represented by the PM3 model and an Abinitio method expressed by Hartree-Fock(HF) model performed at the 6-311 G(d, p) level of theory. The parameters tested for their ability to represent the variations observed in the experimental pKa(s) are atomic and structural properties including Muliken charges on the atoms of hydroxyl group and C=N bond, the angle $C_6-C_1-C_7$, and length of O-H bond. Molecular properties are also used like energies of HOMO and LUMO, hardness(${\eta}$), chemical potential(${\mu}$), total energy(TE), dipole of molecule(DM), and electrophilicity index(W). The relation between pKa values and each of these parameters of the studied compounds is investigated. Depending on these relations, two sets of parameters were constructed for comparison between the PM3 and HF methods. The results obtained favor the Abinitio method for such applications although both models proved to have high predictive power and have sufficient reliability to describe the effect of substituents on pKa values of benzaldoxime compounds under consideration which is clear from the values of correlation coefficient $R^2$ obtained and the consistency between the experimental and the calculated values.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.3
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• pp.285-291
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• 2011

The error motion of a machine tool spindle directly affects the surface errors of machined parts. The error motions of the spindle are not desired errors in the three linear direction motions and two rotating motions. Those are usually due to the imperfect of bearings, stiffness of spindle, assembly errors, external force or unbalance of rotors. The error motions of the spindle have been needed to be decreased to desired goal of spindle's performance. The level of error motion is needed to be estimated during the design and assembly process of the spindle. In this paper, the estimation method for the five degree of freedom (5 D.O.F) error motions of the spindle is suggested. To estimate the error motions of the spindle, waviness of shaft and bearings, external force model was used as input data. And, the estimation models are considering geometric relationship and force equilibrium of the five degree of the freedom. To calculate error motions of the spindle, not only imperfection of the shaft, bearings, such as rolling element bearing, hydrostatic bearing, and aerostatic bearing, but also driving elements such as worm, pulley, and direct driving motor systems, were considered.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.6
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• pp.625-629
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• 2015

In this study, we develop a prognostic method of assessing the stator windings of power generators against water absorption through statistical data analysis and degradation modeling. The 42 windings of the generator are divided into two groups: the absorption and normal groups. A degradation model of a winding is constructed using Fick's second law to predict the level of absorption. By analyzing data from the normal group, we can determine the distribution of the data of normal windings. The health index of a winding is estimated using the directional Mahalanobis distance (DMD) method. Finally, the probability distributions of the failure time of the windings are determined.

• Journal of Nutrition and Health
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• v.31 no.2
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• pp.166-178
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• 1998

The purpose of this study was no investigate serum lipid levels of primary school children and to estimate their intakes of total fat and fatty acids. Subjects fasting blood samples were obtained and analyzed for serum triglycerides(TG), total cholesterol(Chol) and high density lipoprotein-cholesterol (HDL-Chol). Low density lipoprotein cholesterol (LDL-Chol), LDL-Chol/HDL-Chol ratio(LPH), and atherogenic index(AI) were calculated,. Dietary intake of nutrients was assessed by means of a 24-hour recall method using food models and other measuring tools . The serum levels of TG, Chol and LDL-Chol in girls were higher than those in boys, but the serum HDL-Chol level of girls was lower than that of boys. As the degree of obesity increased, the serum TG level of girls was lower than that of boys. As the degree of oesity increased , the serum TG level of girls increased. The serum LDL-Chol level was higher in obese boys than in normal ones. Percentage s of subjects at risk of cardiovascular disease based on corresponding criteria of TG, Chol,HDL-CHol and LDL-Chol were 25.9%, 7.6%, 20.7% and 10.1%, respectively. The serum TG level of children provided with the national school lunch program(NSLP) was lower than that of children without NLSP. The total fat intake of boys was higher than that of girls, but calorie-adjusted fat intake became similar between the two groups. Intakes of polyunsaturated fatty acids(PUFA), monounsaturated fatty acids(MUFA) and saturated fatty acids(SFA) were 13.3$\pm$9.5g, 16.1$\pm$9.3g and 21.4$\pm$14.2g in boys, respecitively , and 12.6$\pm$11.3g, 15.3$\pm$9.7g and 19.9$\pm$13.1g in girls, respectively . The ratios of polyunsaturated /monoun-saturated /saturated /saturated fatty acids(P/M/S) in boys and girls were 0.7/0.8/1.0 and 0.8/0.8/1.0 respectively. The ratios of $\omega$6/$\omega$3 fatty acids in boys and girls were found to be 12.1 /1.0 and 8.6/1.0 , respectively. These results indicated the urgent need of nutritional education in primary schools to prevent further increase in childhood obesity and hyperlipidemia . Therefore, this study will contribute to the establishment of dietary guidelines and health recommendation for school children.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.193-203
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• 2011

With the recent growth of environmental and ecological interests, various river restoration and habitat environment creation projects are being carried out. For this, the estimation of the habitat flow discharge is important. In U.S. and Europe nations, The instream flow incremental methodology (IFIM) has been used to estimate the habitat discharge. IFIM is the method that can be applied to evaluate the flow discharge for the suitable habitat. To use the IFIM in river, a habitat suitability index(HSI) for the target organism is needed. However, HSIs for only two species of Zacco platypus and Zacco temminckii were proposed from the field monitoring. Thus, for the estimation of the ecological flow rate for a group of fish, the development of the HSIs for various fish are necessary. In this study, physical data such as water level and flow rate, chemical data such as acidity and dissolved oxygen, and life data such as fish types and population are collected in Keum river watershed. Based on the 2,736 field data, HSIs for the following 6 fish are developed: Zacco platypus, Zacco temminckii, Microphysogobio yaluensis, Coreoleuciscus splendidus, Pungtungia herzi, Pseudogobio esocinus. Through the comparison with HSIs in the literature, the developed HSIs are modified. Also, the limits of Froude number, pH, and DO for 6 fish are proposed. The HSIs developed in this study can be utilized as a essential data for performing river project evaluations.

• Journal of the Korean Society of Physical Medicine
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• v.19 no.1
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• pp.81-94
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• 2024

PURPOSE: This study aimed to investigate the effect of a progressive balance training program with whole-body vibration stimulation on knee joint pain, dysfunction, psychosocial status, and balance ability in individuals aged ≥ 65 years with knee osteoarthritis. METHODS: A total of 40 individuals aged ≥ 65 years with osteoarthritis of the knees participated in the study. Using a randomization program, participants were assigned to an experimental group (n = 20) or a control group (n = 20). Both groups were assigned a knee strength training program, and a progressive balance training program with whole-body vibration stimulation was assigned to the experimental group. All interventions were conducted three times a week for four weeks. Participants were evaluated for the following: pain (numeric rating scale, NRS), knee dysfunction (Korean version of the Western Ontario and McMaster Universities Arthritis Index, K-WOMAC), fall efficacy (Korean Version Falls Efficacy Scale, K-FES), quality of life (Euro Quality of life 5 Dimension, EQ-5D), and advanced balance scale score (Fullerton advanced balance scale, FAB) before and after the intervention, and the effects of the intervention were compared accordingly between groups. RESULTS: Both groups showed significant differences in the results of the NRS, K-WOMAC, K-FES, and EQ-5D assessments before and after the intervention, and there was a significant difference in the amount of change between the two groups (p < .05). There was a significant improvement in FAB in all but items FAB 8 and FAB 9 after the intervention in the experimental group. In the control group, there was a significant improvement in FAB 1, FAB 2, FAB 7, and FAB total after the intervention (p < .05). In addition, there was a significant difference in the amount of change between the two groups in all items except FAB 8 and FAB 9 (p < .05). CONCLUSION: The progressive balance training program with whole body vibration stimulation is an effective intervention method with clinical significance in improving knee joint pain, knee disability index, psychosocial level, and balance ability in adults aged ≥ 65 with osteoarthritis of the knees.

• Journal of Intelligence and Information Systems
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• v.28 no.1
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• pp.107-129
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• 2022

It is important to preempt new technology because the technology competition is getting much tougher. Stakeholders conduct exploration activities continuously for new technology preoccupancy at the right time. Gartner's Hype Cycle has significant implications for stakeholders. The Hype Cycle is a expectation graph for new technologies which is combining the technology life cycle (S-curve) with the Hype Level. Stakeholders such as R&D investor, CTO(Chef of Technology Officer) and technical personnel are very interested in Gartner's Hype Cycle for new technologies. Because high expectation for new technologies can bring opportunities to maintain investment by securing the legitimacy of R&D investment. However, contrary to the high interest of the industry, the preceding researches faced with limitations aspect of empirical method and source data(news, academic papers, search traffic, patent etc.). In this study, we focused on two research questions. The first research question was 'Is there a difference in the characteristics of the network structure at each stage of the hype cycle?'. To confirm the first research question, the structural characteristics of each stage were confirmed through the component cohesion size. The second research question is 'Is there a pattern of diffusion at each stage of the hype cycle?'. This research question was to be solved through centralization index and network density. The centralization index is a concept of variance, and a higher centralization index means that a small number of nodes are centered in the network. Concentration of a small number of nodes means a star network structure. In the network structure, the star network structure is a centralized structure and shows better diffusion performance than a decentralized network (circle structure). Because the nodes which are the center of information transfer can judge useful information and deliver it to other nodes the fastest. So we confirmed the out-degree centralization index and in-degree centralization index for each stage. For this purpose, we confirmed the structural features of the community and the expectation diffusion patterns using Social Network Serice(SNS) data in 'Gartner Hype Cycle for Artificial Intelligence, 2021'. Twitter data for 30 technologies (excluding four technologies) listed in 'Gartner Hype Cycle for Artificial Intelligence, 2021' were analyzed. Analysis was performed using R program (4.1.1 ver) and Cyram Netminer. From October 31, 2021 to November 9, 2021, 6,766 tweets were searched through the Twitter API, and converting the relationship user's tweet(Source) and user's retweets (Target). As a result, 4,124 edgelists were analyzed. As a reult of the study, we confirmed the structural features and diffusion patterns through analyze the component cohesion size and degree centralization and density. Through this study, we confirmed that the groups of each stage increased number of components as time passed and the density decreased. Also 'Innovation Trigger' which is a group interested in new technologies as a early adopter in the innovation diffusion theory had high out-degree centralization index and the others had higher in-degree centralization index than out-degree. It can be inferred that 'Innovation Trigger' group has the biggest influence, and the diffusion will gradually slow down from the subsequent groups. In this study, network analysis was conducted using social network service data unlike methods of the precedent researches. This is significant in that it provided an idea to expand the method of analysis when analyzing Gartner's hype cycle in the future. In addition, the fact that the innovation diffusion theory was applied to the Gartner's hype cycle's stage in artificial intelligence can be evaluated positively because the Gartner hype cycle has been repeatedly discussed as a theoretical weakness. Also it is expected that this study will provide a new perspective on decision-making on technology investment to stakeholdes.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.8
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• pp.1606-1616
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• 2011

The blood pressure measuring equipment, which is being supplied and used most widely by being recognized convenience and accuracy now generally, is oscillometric blood pressure monitor. However, a change in blood pressure is basically influenced by diverse elements such as each individual's physiological status and physical condition. Thus, the measurement of blood pressure, which used single element called oscillation in blood pressure of being conveyed to cuff, is not considered on physiological elements such as cardiovascular system status and blood vessel stiffness index, and on external elements, thereby being quite in error. Accordingly, this study detected diverse bio-signals and body informations in each individual as the measurement subject such as ECG, PPG, and Korotkoff Sound in order to enhance convenience and accuracy of measuring blood pressure in the complex measurement equipment, thereby having extracted regression method for compensation in error of oscillometric blood pressure measurement on the wrist, and having improved accuracy of measuring blood pressure. To verify a method of improving accuracy, the blood pressure value in each of SBP, DBP, MAP was acquired through 4-stage experimental procedure targeting totally 51 subjects. Prior to experiment, the subjects were divided into two groups such as the experimental group for extracting regression method and the control group for verifying regression method. Its error was analyzed by comparing the reference blood pressure value, which was obtained through the auscultatory method, and the oscillometric blood pressure value on the wrist. To reduce the detected error, the blood pressure compensation regression method was calculated through multiple linear regression analysis on elements of blood pressure, individual body information, PTT, HR, K-Sound PSD change. Verification was carried out on improving significance and accuracy by applying the regression method to the data of control group. In the experimental results, as a result of confirming error on the reference blood pressure value in SBP, DBP, and MAP, which were acquired through applying regression method, the results of $-0.47{\pm}7.45$ mmHg, $-0.23{\pm}7.13$ mmHg, $0.06{\pm}6.39$ mmHg could be obtained. This is not only the numerical value of satisfying the sphygmomanometer reference of AAMI, but also shows the lower result than the numerical value in SBP : $-2.5{\pm}12.2$ mmHg, DBP : $-7.5{\pm}8.4$ mmHg, which is the mean error in the experimental results of Brram's research for verifying accuracy of Omron RX-M, which shows relatively high accuracy among wrist sphygmomanometers. Thus, the blood pressure compensation could be confirmed to be made within significant level.

• Journal of radiological science and technology
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• v.23 no.1
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• pp.49-54
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• 2000

It is important to identify modifiable risk factors for breast cancer, because the breast cancer is one of the major causs of mortality among women. Some reported that obesity is a risk factor for breast cancer, but the results are not constant. Many risk factors are related to the duration of estrogenic stimulation of the breast. In general, early menarche and late menopause are positive risk factors. Human breast cancer has different characteristics according to the status of menopause(premenopause and postmenopause). In premenopausal women, about 60% of circulating estrogen is from the ovaries in the form of estradiol, and the remaining 40% is estrogen formed primarily in the adipose(fat) tissue via aromatization of androstenedion from the adrenal glands. After menopause this adipose cell production of estrone is the main source of estrogens and the level of estrone is maintained approximately at premenopausal levels. This study was undertaken to determine the role of body size and body mass index by status of menopause in development of breast cancer using retrospective case/control study. From March 1991 to February 1997 at the Wonkwang University Hospital, the breast cancer cases(n=72) and controls(n=86) were selected. By statistical analysis method, regression analysis, paired T-test and multiple logistic regression were done to estimate the influenced factors same as height, weight, BMI, age at menarche and age at menopause. The following results were obtained : 1. In premenopausal women, age at menarche was showed comparatively high correlation coefficients and BMI was described prominently highly in postmenopause. 2. At the results of multiple regression analysis, age at monarch, BMI and weight were showed as significant variables. In this method, critical factor ($R^2$) was 0.054. 3. Paired samples T-test was undertaken to test mean difference between two groups of cases and controls. The result of test performance showed a significant difference. 4. In comparison with women whose weight less than 50 kg, the ORs for the upper 5th group was 1.82(95% confidence interval). The heaviest women had a higher risk(OR=1.14, 95% confidence interval $1.12{\sim}1.31$, p=0.005). Higher body mass index was significantly associated with increased risk of premenopausal breast cancer (OR=1.01, 95% confidence interval $1.08{\sim}l.18$, p=0.05).