• Title/Summary/Keyword: reduced sample size

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The Effect of Corporate Social Responsibility and Audit Size on Credit Rating (기업의 사회적 책임과 감사인 규모가 기업신용등급에 미치는 영향)

  • Jeon, Jin-Ho
    • Journal of the Korea Convergence Society
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    • v.9 no.1
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    • pp.1-8
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    • 2018
  • This study analyzed annual final sample data from 159 companies based on firms selected as economic justice companies by Economic Justice Institute in Citizens' Coalition for Economic Justice in South Korea according to interest variables from 2005 until 2011. Analyzed results are as follows. First, higher scores in soundness and corporate social activities among CSR items suggested that corporate credit rating upgraded. This indicates that credit rating institutions give a good evaluation on their social activities and reflect them in credit rating assessment. However, environmental protection satisfaction and corporate credit rating showed the opposite results. Second, high objectivity and contribution to the economic development as well as supervision by giant auditors had substantial effects on higher corporate credit rating. In contrast, high soundness and supervision by giant auditors reduced corporate credit rating. Based on this outcome, it is estimated that there is a discriminatory response among CSR activities in terms of credit rating evaluation conducted by credit rating institution.

Analysis in Microstructures and Co Volume of WC Powder According to the Lifespan of WC-Co Molds for Cold Forging (냉간단조용 WC-Co 금형의 수명에 미치는 WC 분말의 미세구조 및 Co 부피 분율의 분석)

  • Jeongseok Oh;Jini Park;Sang-yeob Lee;Choong-Heui Chung;Jeong-muk Choi;Joon sik Park
    • Journal of the Korean Society for Heat Treatment
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    • v.36 no.5
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    • pp.270-276
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    • 2023
  • In this study, we analyzed two types of cold forging dies commonly used for manufacturing general nuts and screws to investigate the differences in WC powder according to the lifespan. For both Type I and Type II dies, it was observed that as the lifespan of the molds increases, the area fraction of Co becomes larger and the size of the powder becomes smaller. Moreover, there is a trend where the strength also increases as the lifespan gets longer. Actually, the hardness value of the sample with the longest lifespan is ~ 131 HV higher than the specimen of the shortest lifespan, It is noted that the reduction in toughness of the WC-Co mold is caused by insufficient Co and the decrease in contact surface area of WC-Co results in a reduced bonding surface area. The lifespan of cold-working WC molds increases when the W content and the volume fraction of WC are high, and the size of the WC powder is small. The results can significantly enhance producing high-quality molds with an extended lifespan using WC powder for cold forging.

Effect of Calcination Temperature on Ionic Conductivity of All-solid State Battery Electrolytes (하소 온도가 전고체 전지 전해질의 이온전도도에 미치는 영향)

  • Yu Taek Hong;Ji Min Im;Ki Sang Baek;Chan Gyu Kim;Seung Wook Baek;Jung Hyun Kim
    • New & Renewable Energy
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    • v.20 no.2
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    • pp.71-81
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    • 2024
  • In this study, the electrochemical properties of garnet-structured all-solid-state battery electrolytes (Li6.4La3Zr1.4Ta0.6O12, hereafter LLZTO) were assessed by altering the calcination temperature, while maintaining a consistent sintering duration. Among the various heat treatment conditions employed for sample fabrication, the '700_1100' condition, denoting a calcination temperature of 700℃ and a sintering temperature of 1100℃, resulted in the most exceptional ionic conductivity of 4.89 × 10-4 S/cm and a relative density of 88.72% for the LLZTO material. This is attributed to the low calcination temperature of 700℃, leading to reduced grain size and enhanced cohesiveness, thus resulting in a higher sintered density. In addition, a microstructure similar to the typical sintering characteristics observed in Spark Plasma Sintering (SPS) methods was identified in the SEM analysis results under the '700_1100' condition. Consequently, the '700_1100' heat treatment condition was deemed to optimal choice for enhancing ionic conductivity.

On Optimizing LDA-extentions Using a Pre-Clustering (사전 클러스터링을 이용한 LDA-확장법들의 최적화)

  • Kim, Sang-Woon;Koo, Byum-Yong;Choi, Woo-Young
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.3
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    • pp.98-107
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    • 2007
  • For high-dimensional pattern recognition, such as face classification, the small number of training samples leads to the Small Sample Size problem when the number of pattern samples is smaller than the number of dimensionality. Recently, various LDA-extensions have been developed, including LDA, PCA+LDA, and Direct-LDA, to address the problem. This paper proposes a method of improving the classification efficiency by increasing the number of (sub)-classes through pre-clustering a training set prior to the execution of Direct-LDA. In LDA (or Direct-LDA), since the number of classes of the training set puts a limit to the dimensionality to be reduced, it is increased to the number of sub-classes that is obtained through clustering so that the classification performance of LDA-extensions can be improved. In other words, the eigen space of the training set consists of the range space and the null space, and the dimensionality of the range space increases as the number of classes increases. Therefore, when constructing the transformation matrix, through minimizing the null space, the loss of discriminatve information resulted from this space can be minimized. Experimental results for the artificial data of X-OR samples as well as the bench mark face databases of AT&T and Yale demonstrate that the classification efficiency of the proposed method could be improved.

Wage Differentials between Standard and Non-standard Workers (정규-비정규근로자 임금격차)

  • Kim, Yong-Min;Park, Ki Seong
    • Journal of Labour Economics
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    • v.29 no.3
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    • pp.25-48
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    • 2006
  • In this study, the wage differentials between standard and non-standard workers are estimated using the data from the Establishment Employment Survey of 2003. The estimated wage differentials between standard and non-standard workers become greater controlling for the fixed effects of establishments. The within-establishment wage differential is estimated to be 20.7% between male standard and male non-standard workers in unorganized establishments controlling for establishment heterogeneity. However, the estimated overall wage differential is reduced to 6.8% due to the high wages of non-standard workers in large size establishments and the low wages of standard workers in small size establishments. This difference between 20.7% and 6.8% reflects the between-establishment wage differential. In organized establishments, the wage differential becomes larger, 21.8%, between male standard and male non-standard workers. For the male workers, the greatest wage differential between standard and non-standard workers is found in unorganized large size establishments: it is 35.9%. In organized establishments, it contracts to 25.8%. The additional estimations on the probability of becoming non-standard workers are done. For the male sample, the probability of standard workers to become non-standard workers in unorganized establishments is 6.0 percentage points higher than that in small size organized establishments. The probability is 20.7 percentage points higher for the female sample. However, the signs of the interaction terms of union and large size establishments are all negative. While the effect of large size establishments reduces the effect of union on the probability to 7.3 percentage points for the males, it reduces the probability to 16.0 percentage points for the females.

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Report on the improvement of the in vitro and specimen reception environment system (핵의학과 검체 접수 환경시스템의 개선사례 보고)

  • Kim, Jung In;Kang, Mi Ji;Kim, Na Kyung;Park, Ji Sol;Kwon, Won Hyun;Lee, Kyung Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.25 no.2
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    • pp.29-34
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    • 2021
  • Purpose Sample reception environment system in nuclear medicine has not changed much compared to 20 years ago. When preparing sample for in vitro test, there was no significant change because the test was carried out by generating an own specimen from the parent specimen. In this study, We would like to introduce a method that automatically removes the sample cap using the automated decapper equipment and enables automatic reception at the same time. In addition, including a provisional reception system. Materials and Methods In 2019, it was intended to get a device that automatically removes the cap of a patient's blood sample. This equipment is the same as the equipment used in the Department of Laboratory Medicine (Vacuette Ⓡ Unicap Belt Decapper, Greiner bio-one, Austria). However, the purchase was delayed due to differences in tube size, budget, and space. In January 2020, we borrowed domestic automatic decapper equipment and modified it to suit our laboratory environment. After 9 months, we were able to introduce a system that automatically removes the lid of a patient's blood sample and at the same time automatically accepts the test. And, through the provisional reception system, it was possible to know the arrival of the specimen in a short time. Results With the use of an automatic decapper device, the sample cap was automatically removed, and the reception proceeded at the same time. So, it was very efficient at work because it shortened the sample preparation time by about 20 minutes. In addition, it was possible to prevent the examiner's musculoskeletal disorders caused by repeated wrist use. After using the provisional reception system, patients were able to be discharged quickly, and the number of phone calls to confirm the arrival of samples was reduced. Conclusion Most hospitals have about four employees in the nuclear medicine in vitro laboratory. It is effective to use automatic decapper equipment and a provisional reception system for organizations that perform work with the minimum number of personnel.

The Effects of Sibjeondaebotanggamibang on the Treating of Wound (십전대보탕가미방(十全大補湯加味方)의 창상(創傷) 치유(治癒) 효과(效果))

  • Jung, Hoon;Lee, Hyun-Jae;Kim, Binnara;Lee, Chi-Ho;Lee, Eun-Jung;Heo, Dong-Seok;Oh, Min-Seok
    • Journal of Korean Medicine Rehabilitation
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    • v.24 no.3
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    • pp.51-69
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    • 2014
  • Objectives This study was aimed to investigate the effects of Sibjeondaebotanggamibang (SJT) on the wound-induced rats. Methods It was observed the effects of anti-oxidation and anti-inflammation by using of lipopolysaccharide (LPS)-treated RAW 264.7 cells. For the observing on SJT anti-oxidation, it needed to mesure the total amount of polyphenol, DPPH scavenging ability, ABTS scavenging ability and the value of ROS production. In order to observe on the anti-inflammation of SJT, it was mesured the value of No and Cytokine (TNF-${\alpha}$, IL-$1{\beta}$, IL-6). It needed to make a scar (around $2{\times}2cm^2$) on the top of the fascia in the back of the rats and then the rats were divided into 4 groups (n=6). Control group was not treated at all, whereas SJ group was orally medicated SJT, Terra group was per-cutaneously applied Terramycin, and SJ+Terra group was both orally medicated SJT and percutaneously applied Terramycin per day for three weeks. The size of wound was measured with Digimatic Caliper and the blood samples (WBC, neutrophil, monocyte, lymphocyte) were analyzed using Minos-ST, which were collected by cardiac puncture. The effect on inflammatory cytokine (TNF-${\alpha}$, IL-$1{\beta}$, IL-6), immunological cells in synovial fluid was measured. To measure the wound factor expressed by wounded skin sample, we extracted RNA and to investigate MMP-1,2,9 we used RT-PCR. For performing histopathological examinations, we paralyzed the rats by ether, and extracted wounded skin tissues, which were measured by H & E, and monitored on the optical microscope. Results 1. DPPH and ABTS scavenging activity of SJT was increased concentration-dependantly, and ROS scavenging activity was significantly increased (10, $100{\mu}g/ml$). 2. NO production was significantly reduced in SJT treated cells ($100{\mu}g/ml$), both TNF-${\alpha}$ and IL-6 in SJT treated cells (1, 10, $100{\mu}g/ml$), and IL-$1{\beta}$ in SJT treated cells (1, $100{\mu}g/ml$). 1. The size of wound was significantly decreasing in SJ group, Terra group, SJ+Terra group. 2. WBC was significantly reduced in SJ and SJ+Terra group, monocyte in SJ+Terra group. Neutrophil was also reduced in SJ, SJ+Terra group but meaningless. 3. TNF-${\alpha}$ and IL-6 were significantly reduced in SJ group, Terra group, SJ+Terra group, and IL-$1{\beta}$ in SJ+Terra group. 4. mRNA expression in MMP-1 was significantly reduced in SJ group. 5. Collegan production and chronic inflammation were significantly decreased in SJ group, Terra group, SJ+Terra groups. Re-epithelization on the skin in Terra group, SJ+Terra groups was decreased. Conclusions According to this in vitro experiment, Sibjeondaebotanggamibang (SJT) has the effects of anti-oxidative and anti-inflammatory. By in vivo experiment, SJT has the effects of anti-inflammatory. Moreover, the progress of recovery was found visually, heamatologically, genetically and histopathologically. In conclusion, it could be thought that SJT has effect on the treating of wound.

Study of the seroma volume changes in the patients who underwent Accelerated Partial Breast Irradiation (부분유방방사선치료(Accelerated Partial Breast Irradiation) 환자의 장액종(Seroma) 체적 변화에 대한 연구)

  • Kim, Dae Ho;Son, Sang Jun;Mun, Jun Ki;Seo, Seok Jin;Lee, Je Hee
    • The Journal of Korean Society for Radiation Therapy
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    • v.28 no.1
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    • pp.65-75
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    • 2016
  • Purpose : By analyzing seroma volume changes in the patients who underwent Partial breast radiation therapy after breast conserving surgery, we try to contribute to the improvement of radiotherapy effect. Materials and Methods : Enrolled 20 patients who underwent partial breast radiation therapy by ViewRay MRIdian System were subject. After seeking for the size of the removed sample in the patients during surgery and obtained seroma volume changes on a weekly basis. On the Basis of acquired volume, it was compared with age, term from start of the first treatment after surgery, BMI (body mass index) and the extracted sample size during surgery. And using the ViewRay MRIdian RTP System, the figure was analyzed by PTV(=seroma volume + margin) to obtain a specific volume of the Partial breast radiation therapy. Results : The changes of seroma volume from MR simulation to the first treatment (a week) is 0~5% in 8, 5~10% in 3, 10 to 15% in 2, and 20% or more in 5 people. Two patients(A, B patient) among subjects showed the biggest change. The A patient's 100% of the prescribed dose volume is 213.08 cc, PTV is 181.93 cc, seroma volume is 15.3 cc in initial plan. However, while seroma volume decreased 65.36% to 5.3 cc, 100% of the prescribed dose volume was reduced to 3.4% to 102.43 cc and PTV also did 43.6% to 102.54 cc. In the case of the B patient, seroma volume decreased 42.57% from 20.2 cc to 11.6 cc. Because of that, 100% of the prescribed dose volume decreased 8.1% and PTV also did to 40%. Conclusion : As the period between the first therapy and surgery is shorter, the patient is elder and the size of sample is smaller than 100 cc, the change grow bigger. It is desirable to establish an adaptive plan according to each patient's changes of seroma volume through continuous observation. Because partial breast patients is more sensitive than WBRT patients about dose conformity in accordance with the volume change.

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Densification Study of K+-beta-aluminas Prepared from Their Ultra-fine Milled Powder (초미세 분쇄 분말로 제조된 K+-beta-aluminas의 치밀화 연구)

  • Shin, Jae-Ho;Kim, Woo-Sung;Lim, Sung-Ki
    • Applied Chemistry for Engineering
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    • v.16 no.5
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    • pp.648-652
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    • 2005
  • A super ionic conductor, $K^+$-beta-aluminas, which is known to be difficult to obtain in the form of dense sintered density under atmospheric pressure, was pulverized to 350 nm mean particle size using attrition mill. The sample were pressed into tablet form by uniaxial pressing. The specimen was sintered under atmospheric pressure in powder form. Sintering temperature range was $1400^{\circ}C$ to $1650^{\circ}C$ at $50^{\circ}C$ intervals. Additionally, zone sintering was carried out to control the growth grain at high temperature ($1600^{\circ}C$). The density of specimens that were sintered at $1600^{\circ}C$ and $1650^{\circ}C$, and sintered at $1600^{\circ}C$ by zone sintering were about 93% and 95%, respectively. In the case of the lengthened sintering time to 2 h, the density of specimen was reduced to lower than 90%, since the particles were grown to the duplex microstructure.

Positive Effects of Soy Isoflavone Food on Survival of Breast Cancer Patients in China

  • Zhang, Ya-Feng;Kang, Hong-Bin;Li, Bi-Li;Zhang, Rui-Ming
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.2
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    • pp.479-482
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    • 2012
  • Aim: Soy foods are the major source of isoflavones, which are believed to play important roles in genesis of breast cancer and its progression. We here conducted a prospective study to evaluate the association of soy isoflavone food consumption with breast cancer prognosis. Methods: A prospective study was performed from January 2004 and January 2006 in China. Trained interviewers conducted face-to-face interviews using a structured questionnaire to collect information on dietary habits and potential confounding factors. The relative risk [hazard ratio (HR)] and 95% CI were calculated from the Cox regression model for all significant predictors from cancer diagnosis to the endpoint of the study (event). Results: After a median follow up of 52.1 months (range, 9-60 months), a total of 79 breast cancer related deaths were recorded in our study, risk being inversely associated with a high intake of soy isoflavone. With an average intake of soy isoflavone above 17.3 mg/day, the mortality of breast cancer can be reduced by about 38-36%. We also found the decreased breast cancer death with high soy protein intake, with a HR (95% CI) of 0.71 (0.52-0.98). Stratified analysis with reference to the ER status, further demonstrated a better prognosis of ER positive breast cancer with a high intake of soy isoflavone (HR 0.59, 0.40-0.93). Conclusion: Our study shows the soy food intake is associated with longer survival and low recurrence among breast cancer patients. A cohort study with a larger sample size and long term follow-up is now needed.