• Journal of agriculture & life science
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• v.43 no.4
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• pp.9-14
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• 2009

The purpose of this study was to estimate height growth pattern and to derive site index equation for Pinus densiflora grown at Mt. Osu region, Chungnam. A total of 21 repre - sentative trees from the established temporary plots around Boryeng and Cheongyang regions were destructively sampled to measure diameter, height, volume growth per 1-year interval by using of DTRS- 2000 measurement instrument. The Schnute growth function was select ed for height growth prediction using 181 height-age paired observations and derived anamorphic base age invariant site index curves (base index age 30 years). The fitted index and the asymptotic value of Schnute model indicated both 0.96 and 10.8 meter, respectively. The results suggested in this study could be very useful to understand the height growth pattern and productivity of the site quality on Pinus densiflora grown at Mt. Osu region, Chungnam.

• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.75-80
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• 2018

This study was conducted to provide basic data on the dental hygienists Happiness Index and identify factors influencing dental hygienists A self-administered questionnaire survey was conducted dental hygienists in Jeollabuk-do(Jeonju, Iksan, Gunsan) from October to November 2017. Data were analyzed using t-test, ANOVA and multiple regression. As the result of study, Happiness Index of socioeconomic level has increased when the more work career, and more monthly wage, and better interpersonal relationship. Happiness Index of psychological well-being has increased when younger group and more monthly wage, and better interpersonal relationship. Therefore, in order to increase the happiness index of dental hygienists, economic compensation such as incentives and if the education of the communication method of the cases where the most difficulty case of the communication situation in the human relationship is confirmed is preceded, the quality of the medical service provided to the patient due to the happy working life will be improved.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.23 no.4
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• pp.353-360
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• 2010

In this paper, an efficient algorithm is established in order to estimate the plastic properties of power-law hardening bulk specimen materials with one simple spherical indentation impression test. This work is based on a new formulation of representative strain and, therefore, compare to the preceding approaches the fitting parameters are significantly reduced. Moreover, the new definition of representative strain endowed more physical meaning to the representative strain. In order to verify the reliability of the reverse analysis, we have studied a broad set of materials whose property ranges cover essentially all engineering metals and alloys. Based on the indentation force-displacement P-${\delta}$ curves obtained from numerical simulations, the characteristics of the indentation response and material elastoplastic properties are bridged via explicit functions. Next, through the procedure of reverse analysis the yield stress and power-law hardening exponent of bulk specimen materials can be determined. Finally, good agreement between the result from reverse analysis and initial input data from experiment can be observed.

• The Journal of Korean Association of Computer Education
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• v.18 no.2
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• pp.83-90
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• 2015

In an virtualization environment, several virtual machines use physical resources together. If a specific virtual machine uses to much of the computing resources, other machines may not be working properly. There are various method to solve this problem. Most representative study is to migrate a specified virtual machines to a different server, a target server. In this study, server load can be transferred to a target server by the remigrate of the load imposed on virtual machine. It is still problematic that virtual machine has to remigrate to a different server. This thesis has proposed the algorithm determining the remigration targets by applying dynamic thresholds to solve those problems. The migration algorithm applies dynamic thresholds according to the following criteria. Firstly, the usage of CPU, network and memory; secondly, decide the set of artificial machine and the target server based on the resources surpassed thresholds; thirdly, determine artificial machines based on the resource usage in the target server.

• Journal of the Korea Society of Computer and Information
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• v.28 no.5
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• pp.75-82
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• 2023

In collaborative filtering systems, the item rating prediction values calculated by the systems are very important for customer satisfaction with the recommendation list. In the time-aware system, predictions are calculated by reflecting the rating time of users, and in general, exponentially lower weights are assigned to past rating values. In this study, to find out whether the influence of rating time on the rating value varies according to various factors, the correlation between user rating value and rating time is investigated by the degree of user rating activity, the popularity of items, and item genres. As a result, using two types of public datasets, especially in the sparse dataset, significantly different correlation index values were obtained for each factor. Therefore, it is confirmed that the influence weight of the rating time on the rating prediction value should be set differently in consideration of the above-mentioned various factors as well as the density of the dataset.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.62-72
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• 2006

Biological health in aquatic environments has been assessed by several approaches using various bio-taxa. Especially, fish has been identified as one of the best ecological indicators for an integrative health assessments in aquatic environments. In this preliminary study, the necropsy-based approach using the Health Assessment Index (Adams et al., 1993; HAI, Blazer, 2000), was employed for the assessments of aquatic environments influenced by effluent water from wastewater disposal plants (WDP) near a urban stream (i.e., Cap-Stream). For the impact analysis from the effluents, we developed 10 metric necropsy-based model including $M_l\;skin,\;M_2\;fin,\;M_3\;thymus,\;M_4\;spleen,\;M_5\;hindgut,\;M_6\;kidney,\;M_7\;liver.\;M_8\;eyes,\;M_9\;gill,\;and\;M_{10}$ pseudobranch. We set up duplicate controls (natural upstream water plus 5 fishes in each control tank) and duplicate treatments (effluent water from the WDP plus 5 fishes in each treatment tank) in the laboratory. Preliminary results showed that HAI values in the controls were zero, indicating an excellent condition by the criteria of HAI, while the HAI values in the treatments ranged between 40 and 150, indicating a poor condition. Also, various health conditions, based on the index of biological integrity (IBI), species richness, tolerance guilds, and trophic guilds supported the HAI approach. The HAI approach, not applied in Korea, not may be used as an surrogate fer ecological health assessment in lotic ecosystems.

• Journal of dental hygiene science
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• v.15 no.4
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• pp.413-418
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• 2015

Recent cross-sectional studies indicate that obesity is a risk factor for periodontal disease. This study was aimed to investigate whether the four-week weight control program including caloric restriction and exercise training could have an effect on periodontal health. Forty-one obese (body mass index [BMI] ${\geq}25.0$) and five overweight ($23.0{\leq}BMI<25.0$) students participated in the weight control program. Anthropometric data and oral examination data were collected at the baseline and at the 27th day. BMI, waist hip ratio (WHR), and percent of body fat (PBF) of the subjects decreased significantly, but gingival index, sites with bleeding on probing (BOP), and sites with shallow pocket depth didn't show the significant changes in paired t-test. There was no difference in the outcomes according to smoking, drinking alcohol, and sex. Nevertheless, PBF and sites with BOP (r=0.777) and WHR and sites with shallow pocket depth (r=0.444) showed positive correlations. PBF accounted for 58.9% of the variance in sites of BOP in regression analysis. We suggested that obesity might relate with periodontal health, although it was not clear whether weight control could influence on periodontal health directly.

• Journal of Korean Society of Forest Science
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• v.86 no.1
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• pp.17-24
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• 1997

As the first step to estimate the potential natural vegetation distribution of the globe, the best spherical interpolation method was developed to the temperature and precipitation which have close relation to the distribution pattern of world natural vegetation. For developing the interpolation method, a named Light Climatic Dataset composed of 1,060 stations around the globe was randomly divided into halves of feeding side and target side. The discrepancy between the observed and estimated values at the target stations was compared with combinations of parameters and methods. The estimated values were calculated to each combination which is all-out, constant radius and constant station methods in the selection of the feeding stations, n square reciprocal and negative exponential functions in weighting function of distance between feeding stations and each target, and oval weighting in direction of the feeding stations from each target. As a result, it turned out that the spherical interpolation with negative exponential weighting function fed from the constant radius stations ovally weighed yields the best estimates both for temperature and for precipitation. The parameters for temperature are $30^{\circ}$ in constant radius, 0.78 in negative exponential function and 0.4 in oval weighting, and for precipitation are $30^{\circ}$, 0.53 and 0.4, respectively.

• Journal of Naturopathy
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• v.7 no.1
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• pp.1-9
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• 2018

The purpose of this study is to statistically investigate the changes in mean differences of the vascular age types and index, heart beating, vessel elasticity, diastolic reserves contents measured by the fingertip plethysmogram before and after the subjects (49 people) visit the Gotjawal forest for two hours. While there is no significant change in the mean differences of vascular age types and index, heart beating, diastolic reserves contents in the control group before and after the visit, the differences in the test groups gets higher than the control group and shows a significant difference. Moreover, the variance analyses of the mean values of the contents shows a significant change after the visit. There is no significant change in the values of vessel elasticity changes between the groups after the visit, but the change of values is significant in the within group, and it is not significant between group by variance analysis. The differences of the heart beating was insignificant in the within group, but significant between group after the visit. In conclusion this study proves the effects of forest bathing, because the HRV index significantly improved after the bathing. Therefore the b-c-d-e/a ratio may be useful for evaluation of HRV.

• 한국경영정보학회:학술대회논문집
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• 2008.06a
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• pp.141-148
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• 2008

각종 인공지능 기법들을 활용하여, 주식시장의 흐름을 예측하려는 연구가 지금까지 많은 인공지능 및 금융공학의 연구자들에 의해 시도되어 왔으며, 그 결과 다양한 인공지능 기법들이 예측 방법론으로 제시되어 왔다. 이런 가운데 서로 다른 예측모형들이 산출하는 예측결과를 종합 - 보완하는 결합기법에 관련된 연구가 90년대 후반부터 오늘날까지 꾸준하게 발표되고 있다. 본 연구 역시 유전자 알고리즘 기반의 새로 인공지능 예측모형간 결합기법을 제시하고 있다. 다만, 기존의 연구모형들이 각 개별모형 결과의 상대적 가중치에 초점을 맞추고 있었다면, 본 연구의 제안모형은 등락을 판단하는데 활용되는 임계치까지 유전자 알고리즘을 이용해 동시에 최적화하도록 설계되어 있다는 점에서 차별화된다. 제안모형의 유용성을 검증하기 위해, 본 연구에서는 지난 1998년부터 2007년까지의 KOSPI 지수 등락 예측을 위해 구축된 로지스틱 회귀모형, 인공신경망, SVM모형의 결과들을 제안모형을 이용해 결합하였다. 그 결과, 예측력 향상에 본 연구의 제안모형이 기여 할 수 있음을 확인 할 수 있었다.