• Title/Summary/Keyword: and Factor Analysis

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Dominant-species Variation of Soil Microbes by Temperate Change (온도변화에 기인한 토양미생물 우점종의 변화에 관한 연구)

  • Park, Kap-Joo;Lee, Byeong-Chol;Lee, Jae-Seok;Park, Chan-Sun;Cho, Myung-Hwan
    • Korean Journal of Environmental Biology
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    • v.29 no.1
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    • pp.52-60
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    • 2011
  • Today, the weather is changing continually, due to the progress of global warming. As the weather changes, the habitats of different organisms will change as well. It cannot be predicted whether or not the weather will change with each passing day. In particular, the biological distribution of the areas climate change affects constitutes a major factor in determining the natural state of indigenous plants; additionally, plants are constantly exposed to rhizospheric microorganisms, which are bound to be sensitive to these changes. Interest has grown in the relationship between plants and rhizopheric microorganisms. As a result of this interest we elected to research and experiment further. We researched the dominant changes that occur between plants and rhizospheric organisms due to global warming. First, we used temperature as a variable. We employed four different temperatures and four different sites: room temperature ($27^{\circ}C$), $+2^{\circ}C$, $+4^{\circ}C$, and $+6^{\circ}C$. The four different sites we used were populated by the following species: Pinus deniflora, Pinus koraiensis, Quercus acutissima, and Alnus japonica. We counted colonies of these plants and divided them. Then, using 16S rRNA analysis we identified the microorganisms. In conclusion, we identified the following genera, which were as follows: 10 species of Bacillus, 2 Enterobacter species, 4 Pseudomonas species, 1 Arthrobacter species, 1 Chryseobacterium species, and 1 Rhodococcus species. Among these genera, the dominant species in Pinus deniflora was discovered in the same genus, but a different species dominated at $33^{\circ}C$. Additionally, that of Pinus koraiensis changed in both genus and species which changed into the Chryseobacrterium genus from the Bacilus genus at $33^{\circ}C$.

Simultaneous Multiple Transmit Focusing Method with Orthogonal Chirp Signal for Ultrasound Imaging System (초음파 영상 장치에서 직교 쳐프 신호를 이용한 동시 다중 송신집속 기법)

  • 정영관;송태경
    • Journal of Biomedical Engineering Research
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    • v.23 no.1
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    • pp.49-60
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    • 2002
  • Receive dynamic focusing with an array transducer can provide near optimum resolution only in the vicinity of transmit focal depth. A customary method to increase the depth of field is to combine several beams with different focal depths, with an accompanying decrease in the frame rate. In this Paper. we Present a simultaneous multiple transmit focusing method in which chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in a sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels. and the crossorelation function of any Pair of the signals has values smaller than the sidelobe levels of each autocorrelation function. This means that each chirp signal can be separated from the combined received signals and compressed into a short pulse. which is then individually focused on a separate receive beamformer. Next. the individually focused beams are combined to form a frame of image. Theoretically, any two chirp signals defined over two nonoverlapped frequency bands are mutually orthogonal In the present work. however, a tractional overlap of adjacent frequency bands is permitted to design more chirp signals within a given transducer bandwidth. The elevation of the rosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals We also observe that the Proposed method provides better images when the low frequency chirp is focused at a near Point and the high frequency chirp at a far point along the depth. better lateral resolution is obtained at the far field with reasonable SNR due to the SNR gain in Pulse compression Imaging .

Medicinal Herb Extracts Attenuate 1-Chloro-2,4dinitrobenzene-induced Development of Atopic Dermatitis-like Skin Lesions (한약재 단일 추출물 및 복합 추출물을 이용한 아토피성 피부염 억제 효과)

  • Lee, Moon Hee;Han, Min Ho;Yoon, Jung Jeh;Song, Myung Kyu;Kim, Min Ju;Hong, Su Hyun;Choi, Byung Tae;Kim, Byung Woo;Hwang, Hye Jin;Choi, Yung Hyun
    • Journal of Life Science
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    • v.24 no.8
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    • pp.851-859
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    • 2014
  • The present study was designed to investigate whether ethanol extracts of Sophora flavescens (GS), Glycyrrhiza uralensis (GC), Dictamnus dasycarpus (BSP), and their mixtures (GGB-1, -2, -3, and -4) inhibit 1-chloro-2,4-dinitrobenzene (DNCB)-induced atopic dermatitis (AD) in a mouse model. DNCB was topically applied on the dorsal surface of Balb/c mice to induce AD-like skin lesions. The pathological phenotypes of AD, such as erythema, ear thickness, edema, scabs, and discharge, were significantly decreased in the GGB (DNCB + GS:GC:BSP = 3:1:1 mixture)-1-treated groups compared with the other treated groups. The weight of the spleen in immune organs was significantly decreased in the GGB-1-treated groups, whereas the weight of the liver in a control group was similar to that of the groups treated with the samples. Furthermore, toluidine blue staining analysis, a method used to specifically identify mast cells, showed that master cell infiltration into the dermis of the GGB-1-treated group was significantly decreased. The immunoglobulin E concentration was lower in the GGB-1-treated group. In addition, the levels of inflammatory cytokines (interferon-${\gamma}$, interleukin-1, 4, 5, 6, and 13, $1{\beta}$, and tumor necrosis factor-${\alpha}$) were also significantly reduced in the GGB-1-treated group. Taken together, these results suggest that a mixture of GS, GC, and BSP in a proportion of 3:1:1 (GGB-1) may contribute to the relief of AD symptoms and may be considered an excellent candidate for an AD therapeutic drug.

Effect of thread design on the marginal bone stresses around dental implant (임플란트 나사산 디자인이 변연골 응력에 미치는 영향)

  • Lee, Sang-Hyun;Jo, Kwang-Heon;Lee, Kyu-Bok
    • The Journal of Korean Academy of Prosthodontics
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    • v.49 no.4
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    • pp.316-323
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    • 2011
  • Purpose: The purpose of this study was to investigate the effect of different thread designs on the marginal bone stresses around dental implant. Materials and methods: Standard ITI implant(ITI Dental Implant System; Straumann AG, Waldenburg, Switzerland), 4.1 mm in diameter and 10 mm in length, was selected as control. Test implants of four different thread patterns were created based on control implant, i.e. maintaining all geometrical design of control implant except thread pattern. Four thread designs used in test implants include (1) small V-shape screw (model A), (2) large V-shape screw (model B), (3) buttress screw (model C), and (4) trapezoid screw (model D). Surface area for unit length of implant was 14.4 $mm^2$ (control), 21.7 (small V-shape screw), 20.6 (large V-shape screw), 17.0 (buttress screw) and 28.7 $mm^2$ (trapezoid screw). Finite element models of implant/bone complex were created using an axisymmetric scheme with the use of NISA II/DISPLAY III (Engineering Mechanics Research Corporation, Troy, MI, USA). A load of 100 N applied to the central node on the crown top either in parallel direction or at 30 degree to the implant axis (in order to apply non-axial load to the implant NKTP type 34 element was employed). Quantification and comparison of the peak stress in the marginal bone of each implant model was made using a series of regression analyses based on the stress data calculated at the 5 reference points which were set at 0.2, 0.4, 0.6, 0.8 and 1.0 mm from implant wall on the marginal bone surface. Results: Results showed that although severe stress concentration on the marginal bone cannot be avoided a substantial reduction in the peak stress is achievable using different thread design. The peak marginal bone stresses under vertical loading condition were 7.84, 6.45, 5.96, 6.85, 5.39 MPa for control and model A, B, C and D, respectively. And 29.18, 26.45, 25.12, 27.37, 23.58 MPa when subject to inclined loading. Conclusion: It was concluded that the thread design is an important influential factor to the marginal bone stresses.

Anti-proliferative Activities of Solvent Fractions of Lees Extracts in Human Colorectal HCT116 Cells (대장암 세포주에서 주박 추출물의 유기용매 분획물의 항성장 활성)

  • Kang, Hyung-Taek;Lee, Seung Hoon;Kim, Soon Young;Kim, Mi-Sun;Shin, Woo-Chang;Sohn, Ho-Yong;Kim, Jong-Sik
    • Journal of Life Science
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    • v.24 no.9
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    • pp.967-972
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    • 2014
  • In the present study, we prepared eighty-five different kinds of lees extracts and their solvent fractions and investigated their anti-proliferative activities against human colorectal cancer HCT116 cells. HCT116 cells were treated with eighty-five solvent fractions of lees extracts and then cell viability was measured using MTS assay. Among the treated solvent fractions, three solvent fractions (KSD-E1-3, KSD-E2-3, and KSD-E4-3) were selected based on cell viability assay. In addition, we performed an oligo DNA microarray analysis to analyze the gene expression changes by treatment of KSD-E1-3 in HCT116 cells. Among the upregulated genes, we selected 4 genes (NAG-1, ATF3, p21, and DDIT3) and performed RT-PCR using gene-specific primers. Among the treated solvent fractions, KSD-E1-3 dramatically induced the expressions of the four selected genes. In addition, we investigated whether the upregulations of those genes were dependent on the transcription factor p53's presence using p53 null HCT116 cells. The results indicate that the upregulations of NAG-1, ATF3, and DDIT3 are not dependent on the p53 presence, whereas p21 is dependent on the p53 presence. These findings may help to understand the molecular mechanisms of the anti-proliferative activity mediated by rice wine lees in human colorectal cancer cells.

The effect of cavity wall property on the shear bond strength test using iris method (Iris 법을 이용한 전단접착강도 측정에서 와동벽의 영향)

  • Kim, Dong-Hwan;Bae, Ji-Hyun;Cho, Byeong-Hoon;Lee, In-Bog;Baek, Seung-Ho;Ryu, Hyun-Mi;Son, Ho-Hyun;Um, Chung-Moon;Kwon, Hyuck-Choon
    • Restorative Dentistry and Endodontics
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    • v.29 no.2
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    • pp.170-176
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    • 2004
  • Objectives : In the unique metal iris method. the developing interfacial gap at the cavity floor resulting from the cavity wall property during polymerizing composite resin might affect the nominal shear bond strength values. The aim of this study is to evaluate that the iris method reduces the cohesive failure in the substrates and the cavity wall property effects on the shear bond strength tests using iris method. Materials and Methods : The occlusal dentin of 64 extracted human molars were randomly divided into 4 groups to simulate two different levels of cavity wall property (metal and dentin iris) and two different materials ($ONE-STEP^{\circledR}$ and $ALL-BOND^{\circledR}$ 2) for each wall property. After positioning the iris on the dentin surface. composite resin was packed and light-cured. After 24 hours the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Fracture analysis was performed using a microscope and SEM. The data was analyzed statistically by a two-way ANOV A and t-test. Results : The shear bond strength with metal iris was significant higher than those with dentin iris (p=0.034). Using $ONE-STEP^{\circledR}$, the shear bond strength with metal iris was significant higher than those with dentin iris (p=0.005), but not in $ALL-BOND^{\circledR}$ 2 (p=0.774). The incidence of cohesive failure was very lower than other shear bond strength tests that did not use iris method. Conclusions:The iris method may significantly reduce the cohesive failures in the substrates. According to the bonding agent systems. the shear bond strength was affected by the cavity wall property.

A Study on Applicability of Stabilizing Pile to Foundation Soil of Slope with Various Strength Parameters (사면하부지반의 강도정수에 따른 억지말뚝 적용성 연구)

  • Lee, Seung-Hyun;Jang, In-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.10
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    • pp.331-337
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    • 2016
  • Several foundation soil conditions below a homogeneous sand slope were assumed and slope stability analyses were conducted to determine the soil condition, in which a stabilizing pile can be used to increase the factor of safety against sliding. The assumed heights of the sand slope were 5m and 10m. For a 5m slope height, a stabilizing pile can be used in the foundation soil with a $15^{\circ}$ internal friction angle and a cohesion of 10kPa. For a 10m slope height, a stabilizing pile can be used in the foundation soil with a $20^{\circ}$ internal friction angle and a cohesion of 10kPa and a stabilizing pile can be used in the foundation soil with a $0^{\circ}$ internal friction angle and 40kPa, 45kPa and 50kPa of cohesion. According to the analysis results of stabilizing pile-reinforced foundation soil, the length of the stabilizing pile and magnitude of the maximum bending moment were strongly affected by the internal friction angle of the foundation soil. The lengths of stabilizing pile, for an internal friction angle of $0^{\circ}$ were 4.6, 8.0 times greater than those with an internal friction angle of $5^{\circ}$. The magnitude of the maximum bending moment of the stabilizing pile for an internal friction angle of $0^{\circ}$ was 24.6 times greater than that for an internal friction angle of $5^{\circ}$. Practically, a stabilizing pile cannot be used for foundation soil with an internal friction angle of $0^{\circ}$. Considering the results derived from this study, the effects of a stabilizing pile can be maximized for soft foundation soil that is embanked with a slow construction speed.

Risk Factors of Socio-Demographic Variables to Depressive Symptoms and Suicidality in Elderly Who Live Alone at One Urban Region (일 도시지역의 독거노인에 있어서 우울증상 및 자살경향성에 영향을 미치는 인구학적 변인에 대한 고찰)

  • Park, Hoon-Sub;Oh, Hee-jin;Kwon, Min-Young;Kang, Min-Jeong;Eun, Tae-Kyung;Seo, Min-Cheol;Oh, Jong-Kil;Kim, Eui-Joong;Joo, Eun-Jeong;Bang, Soo-Young;Lee, Kyu Young
    • Korean Journal of Psychosomatic Medicine
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    • v.23 no.1
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    • pp.36-46
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    • 2015
  • Objectives: To understand the risk factors of demographic data in geriatric depression scale, and suicidality among in elderly who live alone at one urban region. Methods:In 2009, 589 elderly who live alone(age${\geq}$65) were carried out a survey about several socio-demographic data, Korean version of the Geriatric Depression Scale(SGDS-K) and Suicidal Ideation Questionnaire (SIQ). Statistical analysis was performed for the collected data. Results: Mean age of elderly who live alone is 75.69(SD 6.17). 40.1% of participants uneducated, 31.4% graduate from elementary school, 12.9% graduate from high school, 11.7% graduate from middle school, 3.2% graduate from university. Religionless, having past history of depression or physical diseases, low subjective satisfaction of family situation, and not having any social group activity have significance to depressive symptoms of elderly who live alone. Having past history of depression, religionless, low subjective satisfaction of family situation have significance to suicidality. Especially, low subjective satisfaction of family situation and having past history of depression are powerful demographic factor both depressive symptoms and suicidality of elderly who live alone. Conclusions: When we take care elderly who live alone, we should consider many things, but especially the social support network such as family satisfaction and past history of depression for reducing or preventing their depression and suicide both elderly depression and suicide who live alone.

Development of a water quality prediction model for mineral springs in the metropolitan area using machine learning (머신러닝을 활용한 수도권 약수터 수질 예측 모델 개발)

  • Yeong-Woo Lim;Ji-Yeon Eom;Kee-Young Kwahk
    • Journal of Intelligence and Information Systems
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    • v.29 no.1
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    • pp.307-325
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    • 2023
  • Due to the prolonged COVID-19 pandemic, the frequency of people who are tired of living indoors visiting nearby mountains and national parks to relieve depression and lethargy has exploded. There is a place where thousands of people who came out of nature stop walking and breathe and rest, that is the mineral spring. Even in mountains or national parks, there are about 600 mineral springs that can be found occasionally in neighboring parks or trails in the metropolitan area. However, due to irregular and manual water quality tests, people drink mineral water without knowing the test results in real time. Therefore, in this study, we intend to develop a model that can predict the quality of the spring water in real time by exploring the factors affecting the quality of the spring water and collecting data scattered in various places. After limiting the regions to Seoul and Gyeonggi-do due to the limitations of data collection, we obtained data on water quality tests from 2015 to 2020 for about 300 mineral springs in 18 cities where data management is well performed. A total of 10 factors were finally selected after two rounds of review among various factors that are considered to affect the suitability of the mineral spring water quality. Using AutoML, an automated machine learning technology that has recently been attracting attention, we derived the top 5 models based on prediction performance among about 20 machine learning methods. Among them, the catboost model has the highest performance with a prediction classification accuracy of 75.26%. In addition, as a result of examining the absolute influence of the variables used in the analysis through the SHAP method on the prediction, the most important factor was whether or not a water quality test was judged nonconforming in the previous water quality test. It was confirmed that the temperature on the day of the inspection and the altitude of the mineral spring had an influence on whether the water quality was unsuitable.

Earnings Management of Firms Selected as Preliminary Unicorn (예비유니콘 선정기업의 이익조정에 대한 연구)

  • HAKJUN, HAN;DONGHOON, YANG
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.18 no.1
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    • pp.173-188
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    • 2023
  • This paper analyzed the Earnings management of firms selected as preliminary Unicorn. If a manager is selected as a preliminary unicorn firm, he can receive financial support of up to 20 billion won, creating a factor in managing the manager's earnings. The motive for management's earnings management is related to the capital market. Accounting information is used by investors and financial analysts, and corporate profits affect corporate value. Therefore, if the accounting earning is adjusted upward, the corporate value will be raised and investment conditions will be favorable. In this paper, earnings quality was measured by the modified Jones model of Dechow et al.(1995) by the ROA control model of Kothari et al.(2005) among the discretionary accruals estimated using an alternative accrual prediction model. Competing similar companies in the same market as the selected companies were formed, and the discretionary accruals were mutually compared to verify the research hypotheses, and only the selected companies were analyzed for the audit year and after the audit year. As a result of the analysis, it was found that the companies selected as preliminary unicorns had higher earnings management compared to the corresponding companies in question, which had a negative impact on the quality of accounting profits. It was found that the companies selected as preliminary unicorns continued to receive incentives for management's earnings management even after being selected. These results indicate that the companies selected as prospective unicorns are recognized for their value in the market through external growth rather than internal growth, and thus, incentives for management's earnings management to attract investment from external investors under favorable conditions are continuing. In the future preliminary unicorn selection evaluation, it was possible to present what needs to be reviewed on the quality of accounting earning. The implication of this paper is that the factors of management's earnings management eventually hinder investors and creditors from judging the reliability of accounting information. It was suggested that a policy alternative for the K-Unicorn Project, which enhances reliability were presented by reflecting the evaluation of earnings quality through discretionary accruals.

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