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Quantitative Study on Threshold Condition of Critical Non-propagating Crack (임계정류피로크랙의 하한계 전파조건의 정량적 고찰)

  • Kim, Min-Gun
    • Journal of Industrial Technology
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    • v.30 no.B
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    • pp.17-23
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    • 2010
  • Since the propagation of a short fatigue crack is directly related to the large crack which causes the fracture of bulk specimen, the detailed study on the propagation of the short crack is essential to prevent the fatigue fracture. However, a number of recent studies have demonstrated that the short crack can grow at a low applied stress level which are predicted from the threshold condition of large crack. In present study, the threshold condition for the propagation of short fatigue crack is examined with respect to the micro-structure and cyclic loading history. Specimens employed in this study were decarburized eutectoid steels which have various decarburized ferrite volume fraction. Rotating bending fatigue test was carried out on these specimens with the special emphasis on the "critical non-propagating crack length" It is found that the reduction of the endurance limit of their particular micro-structures can be due to the increase of the length of critical non-propagating crack, and the quantitative relationship between the threshold stress ${\sigma}_{wo}$ and the critical non-propagating crack length $L_c$ can be written as ${\sigma}_{wo}{^m}{\cdot}L_c=C$ where m,C is constant. Further experiments were carried out on cyclic loading history on the length of critical non-propagating crack. It shown that the length of critical non-propagating crack is closely related to cyclic loading history.

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Implementation of Topological Operators for the Effective Non-manifold CAD System (효율적인 복합다양체 CAD 시스템 위상 작업자 구현)

  • 최국헌
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2004.10a
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    • pp.382-387
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    • 2004
  • As the increasing needs in the industrial filed, many studies for the 3D CAD system are carried out. There are two types of 3D CAD system. One is manifold modeler, the other is non-manifold modeler. In the manifold modeler only 3D objects can be modeled. In the non-manifold modeler 3D, 2D, 1D, and 0D objects can be modeled in a unified data structure. Recently there are many studies on the non-manifold modeler. Most of them are focused on finding unknown topological entities and representing all kinds of topological entities found. In this paper, efficient data structure is selected. The boundary information on a face and an edge is included in this data structure. The boundary information on a vertex is excluded considering the frequency of usage. Because the disk cycle information is not required in most case of modeling. It is compact. It stores essential non-manifold information such as loop cycle and radial cycle. A suitable Euler-Poincare equation is studied and selected. Using the efficient data structure and the selected Euler-Poincare equation, 18 basic Euler operators are implemented. Several 3D models are created using the implemented modeler. A non-manifold modeling can be carried out using the implemented 3D CAD system. The results of this paper could be used in the further studies such as an implementation of Boolean operators, and a translation of 2D CAD drawings to 3D models.

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Assessment of the Quality of Non-Financial Information Disclosure: Empirical Evidence from Listed Companies in Vietnam

  • LE, Binh Thi Hai;NGUYEN, Nhat Quoc;NGUYEN, Cong Van
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.5
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    • pp.111-118
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    • 2022
  • The purpose of this research is to evaluate the quality of non-financial information disclosure by companies listed on the Vietnamese stock exchange. In 2019, 140 annual reports from 140 companies listed on the Vietnam Stock Exchange were included in the research sample. The remaining 134 reports were eligible study after removing those that lacked essential data. Using the statistical software SPSS version 25 and Excel office software, the study has selected the data processing method and the disproportionate disclosure index method to evaluate the quality of non-financial information disclosure of companies. The findings of the study demonstrate that companies listed on the Vietnam stock exchange are particularly interested in giving non-financial information to financial statement consumers as required by law, although the level of disclosure is still inadequate. The findings also illustrate the varying levels of non-financial information disclosure by category of information, as well as substantial disparities between them (general information about the company, environmental and social information, corporate governance information, etc.). The findings of the study show that the majority of Vietnam's publicly traded enterprises are less interested in reporting environmental information.

The Effect of Oregano and Cinnamon Essential Oils on Fermentation Quality and Aerobic Stability of Field Pea Silages

  • Soycan-Onenc, Sibel;Koc, Fisun;Coskuntuna, Levent;Ozduven, M. Levent;Gumus, Tuncay
    • Asian-Australasian Journal of Animal Sciences
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    • v.28 no.9
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    • pp.1281-1287
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    • 2015
  • This study was performed to determine the effect of field pea silages which were the organic acid (OA) alternative of oregano and cinnamon essential oils on fermentation quality and aerobic stability. Whole crop pea was harvested at full pod stage and wilted in the laboratory at the 48 h. The chopped pea was mixed and divided into equal portions allocated to five groups: CON (non-treated), distilled water, denoted as control group; OA group, a mixture of 60% formic acid, 20% sodium formate and 20% water applied at a rate of 5 g/kg fresh forage (Silofarm Liquid, Farmavet); origanum (ORE) group, Origanum onites essential oil at 400 mg/kg fresh forage; cinnamon (CIN) group, cinnamon essential oil at 400 mg/kg fresh forage; origanum+cinnamon (ORECIN) group, a mixture of ORE and CIN applied at an equal rate of 400 mg/kg fresh forage. Cinnamon decreased acetic acid (AA), ammonia nitrogen ($NH_3-N$) and weight loss (WL) at the end of 60 days silage. Crude protein (CP) and dry matter (DM) increased by cinnamon essential oil. Yeasts were not detected in any treatments, including the control, after 7 days of air exposure. The $CO_2$ amount decreased and the formation mold was inhibited in the aerobic period by the addition of cinnamon oil. Oregano did not show a similar effect, but when it was used with cinnamon, it showed synergic effect on AA and during aerobic period, it showed antagonistic effect on mold formation and DM losses. It was found in this study that cinnamon can be an alternative to organic acids.

Effects of Normal Saline and Essential Oil Gargling on Bacterial Colonization in Intubated Patients for General Anesthesia (생리식염수와 에센셜오일을 이용한 가글링이 전신마취를 위한 경구 기관 내 삽관 환자의 균집락화에 미치는 영향)

  • Ko, Sang Jin;Na, Yeon Kyung;Hong, Hae Sook
    • Journal of Korean Biological Nursing Science
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    • v.16 no.2
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    • pp.123-132
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    • 2014
  • Purpose: The purpose of this study was to compare and analyze the effects of gargling using normal saline or essential oil on oral bacterial colonization of the subjects who did transoral endotracheal intubation for general anesthesia. Methods: A repeated measures, non-equivalent control group pretest-posttest design was used in this study. The subjects of the study included 58 people; the gargling group with normal saline (n=19); the gargling group with essential oil (n=20); and the control group (n=19). Data were collected from University hospitals in a Korean province from August 13-31, 2012. The collected data were analyzed with $X^2$-test, t-test, ANOVA and Scheff$\acute{e}$ test using SPSS 19.0. Results: Although statistically significant differences among the three groups did not appear in the change of the aerobic bacterial colony before and after the experiments, the aerobic bacterial colony of the gargling group with normal saline ($71.58{\pm}143.39$) and the group with essential oil ($6.95{\pm}332.07$) have increased less compared to the control group ($145.42{\pm}385.01$). The change of the anaerobic bacterial colony before and after the experiments, the control group was ($167.58{\pm}483.58$) and the gargling group with essential oil was ($169.70{\pm}291.60$) and increased, while the gargling group with normal saline ($-42{\pm}331.09$) reduced, but statistically significant differences have not appeared. Conclusion: These findings indicated that oral gargling with normal saline is effective in reducing anaerobic bacterial colonization.

Effects of Amino Acid in In-vitro Maturation Medium on Nuclear Maturation and Embryo Development of Korean Native Cow (체외성숙 배지에 아미노산의 첨가가 한우 난포란의 핵성숙과 배발달에 미치는 영향)

  • 박용수;김소섭;최수호;박노찬;변명대;박흠대
    • Reproductive and Developmental Biology
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    • v.28 no.1
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    • pp.29-36
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    • 2004
  • The objective of this study was to investigate the effects of amino acid supplementation of oocyte maturation medium on 1st polar body(PB) extrusion, embryo development and blastocsyt cell number. In experiment 1, Cumulus oocyte complexes(COCs) were matured in in vitro maturation(IVM) medium supplemented with 1, 2, or 4-fold of 10 $\mu$l/ml MEM non-essential amino acid(NEAA) and 20 Park, $\mu$ l/ml BME essential amino acid(EAA). The PB extrusion rate of oocytes matured in 1-fold amino acid group was significantly higher than that matured in medium without amino acid (p<0.05), but it was decreased by the increase of the dosage of amino acid. There were no difference in the percentage of embryos reaching 2-cell, 8-cell and blastocyst in all treatments. The number of trophectoderm(TE) cells and total cell number of blastocysts were highest in 2-fold amino acid group, and the number of inner cell mass(ICM) cells was increased by the increase of the dosage of amino acid. In experiment 2, COCs were matured in IVM medium with 1, 5, or 10 mg/ml lactalbumin hydrolysate(LAH). The PB extrusion rate of oocytes matured in medium with 5 mg LAH was significantly higher than that matured in medium with 1 mg LAH (p<0.05). The development rate to the blastocyst stage was significantly higher in non-supplement and 1 mg LAH group than in 5 mg and 10 mg LAH group (p<0.05). The number of TE cells and total cell number did not differ among treatment groups, but the number of ICM cells was increased by the increase of LAH supplement. These results suggested that the supplement of certain group of amino acid in IVM medium effective on the quality of blastocyst, and further studies will be accompany with the search of new sources of amino acid used for the use of in vitro embryo production.

A Review on Treatment of Essential Tremor in Traditional Chinese Medicine (본태성 진전에 대한 중의학 연구동향)

  • Shin, A-Ri;Bae, Yeong-Long;Lim, Jae-Yu;Lee, Seung-Hwan;Kim, Sang-Ho;Lim, Jung-Hwa
    • Journal of Oriental Neuropsychiatry
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    • v.28 no.2
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    • pp.95-107
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    • 2017
  • Objectives: This study was performed to review studies on Essential Tremor (ET) in Traditional Chinese medicine (TCM). Methods: We reviewed papers in the China National Knowledge Infrastructure (CNKI) from 2007~2016. Search keywords were 原发性震颤, 特发性震颤, essential tremor and idiopathic tremor, and excluded non-clinical studies, non-related to ET or TCM studies, theses for degrees and non-Randomized Controlled Trial (RCT). The quality of the articles was assessed by Jadad scale and the Risk of Bias (RoB). Results: Thirteen studies were selected. 'Criteria for the diagnosis of ET' was most frequently used as diagnostic criteria. 'Tremor rating scale' was primarily used for outcome measurement. Meta-analysis of nine trials revealed the effective rate of acupuncture and Western medicine (WM+Acu) groups was significantly higher compared to the WM group (RR: 1.48, 95 percent CI: 1.20 to 1.82, p=0.0002, $I^2=0$ percent) and tremor rating scale was also significantly decreased in the treatment group (MD: -1.35, 95 percent CI: -2.17 to -0.54, p=0.001, $I^2=0$ percent). Also, effective rates of Electro-acupuncture (EA) and Chinese herbal medicine (CHM) groups were significantly higher than that of the WM group {(RR: 1.53, 95 percent CI: 1.22 to 1.92, p=0.0003, $I^2=0$ percent) in EA vs. WM and (RR: 1.35, 95 percent CI: 1.16 to 1.57, p<0.0001, $I^2=0$ percent) in CHM vs. WM}. However, the quality of selected clinical studies was poor. Conclusions: Treatment of ET in TCM may be more effective and safe than in Western medicine. Therefore, we hope this study will lead to further clinical research on treatment of ET in Korean medicine.

The effect of artificial lights on the growth and quality of hydroponic cultivated barley (Hordeum vulgare L.) sprouts (인공조명이 수경재배 새싹보리(Hordeum vulgare L.)의 생장과 품질에 미치는 영향)

  • Kim, Ju-Sung
    • Journal of Plant Biotechnology
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    • v.48 no.1
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    • pp.62-70
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    • 2021
  • We analyzed the growth and quality characteristics of barley sprouts grown under artificial light sources consisting of a fluorescent lamp or light-emitting diode (LED) in an aquaculture system (grown with water only, without nutrients). At the end of the observation period, the shoots grown under the fluorescent lamp treatment were the longest, followed by the LED treatment and natural light-treatment. It was also observed that growth was faster for sprouts subjected to a non-sterilizing treatment than those subjected to a 70% ethanol treatment. As the seed sowing rate for planting trays increased, the yield of harvested barley sprouts increased; among light treatments, the natural light treatment resulted in the lowest yield, while the fluorescent light treatment resulted in the highest. The total phenol and total flavonoid contents of extracts of the barley sprouts were highest for the natural light treatment, but TEAC and FRAP were both highest for the fluorescent lamp treatment. The essential amino acid content ranged from 41.64 to 45.93 mg/g and was relatively higher for the natural light treatment than the other two treatments, while the content of non-essential amino acids was highest for the LED treatment. The total amino acid content was highest for the LED treatment at 97.47 ± 6.30 mg/g, for which the content of non-essential amino acids (53.17%) was higher than that of essential amino acids (46.83%).

Efficient Filtering Method for RFID Data Streams (RFID 데이터 스트림의 효율적인 필터링 기법)

  • Yun, Hong-Won
    • The Journal of the Korea Contents Association
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    • v.7 no.10
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    • pp.27-35
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    • 2007
  • Radio Frequency Identification(RFID) technology is set to play an essential role in object tracking or supply chain management systems. New challenges for RFID data management are needed in the RFID applications. RFID data are generated quickly and automatically, and can be used for object tracking, or for real-time monitoring. These applications are mostly associated with the timestamps when the events happen. In this paper, we propose a temporal RFID data model to maintain the history of events and state changes and to monitor the states of RFID objects. Also we propose data filtering method of non active data based on temporal RFID data model. This data model involves essential basic operations for RFID data. We show increased query performance through the data filtering method of non active data.

WENO methodology for UHD TV Image Quality Improvement (WENO 방법을 이용한 UHD TV 화질 개선)

  • Yi, Dokkyun;Park, Jieun
    • Journal of Digital Convergence
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    • v.16 no.4
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    • pp.149-155
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    • 2018
  • It has passed the era of Full High Definition Television (FHD) and ended the era of Ultra High Definition Television (UHD). We will talk about the problems caused by the difference in the number of pixels in the TVs and introduce a method to improve them. This method is a method of performing an interpolation method suitable for a given image with Weighted Essential Non-Oscillation (WENO). Thus, it is possible to reduce the distortion of the image and to ensure a better image quality. Therefore, if we use the WENO methodology, when we watch old video material on UHD TV, we can enjoy high definition of UHD TV without changing the number of pixels.