• Journal of Integrative Natural Science
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• v.12 no.3
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• pp.91-99
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• 2019

Many researchers in various study fields use the two sample t-test to confirm their treatment effects. The two sample t-test is generally used for small samples, and assumes that two independent random samples are selected from normal populations, and the population variances are unknown. Researchers often conduct F-test, the test of equality of variances, before testing the treatment effects, and the test statistic or confidence interval for the two sample t-test has two formats according to whether the variances are equal or not. Researchers using the two sample t-test often want to know how large sample sizes they need to get reliable test results. This research gives some guidelines for sample sizes to them through simulation works. The simulation had run for normal populations with the different ratios of two variances for different sample sizes (${\leq}30$). The simulation results are as follows. First, if one has no idea equality of variances but he/she can assume the difference is moderate, it is safe to use sample size at least 20 in terms of the nominal level of significance. Second, the power of F-test for the equality of variances is very low when the sample sizes are small (<30) even though the ratio of two variances is equal to 2. Third, the sample sizes at least 10 for the two sample t-test are recommendable in terms of the nominal level of significance and the error limit.

• The Journal of Internal Korean Medicine
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• v.19 no.2
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• pp.392-410
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• 1998

In order to investigate the effect of Alismatis Lhizoma on hyperlipidemia, experimental studies were performed on hyperlipidemia rats. Hyperlipidemia model (controll group) was induced by 1% cholesterol fed-diet for 8 weeks. Sample I group fed with 1% cholesterol and 4% Alismatis Lhizoma diet for 8 weeks. Sample II group fed with 1% cholesterol and 8% Alismatis Lhizoma diet for 8 weeks. The contents of serum total cholesterol, triglyceride, free fatty acid, phospholipid, HDL-cholesterol and LDL-cholesterol were measured, and fat accumulation in liver and the change of elastic and collagenous fiber in aortic wall were observed. The results were summurized as follows ; 1. The content of total cholesterol in the serum compared with control group tended to be decreased in sample group, and then sample I group showed a significant value. 2. The content of triglyceride in the serum compared with control group tended to be decreased in sample group, and then sample I group showed a significant value. 3. The content of free fat acid in the serum compared with control group tended to be decreased in sample group, but did not show a significance. 4. The content of phospholipid in the serum compared with control group tended to be decreased in sample group, and then sample I group showed a significant value. 5. The content of HDL-cholesterol in the serum compared with control group tended to be increased in sample group, and then sample II group showed a significant value. 6. The content of LDL-cholesterol in the serum compared with control group tended to be decreased in sample group, and then sample I group showed a significant value. 7. The lipophagy in liver compared with control group tended to be repressed in sample group. 8. The change of elastic and collagenous fiber lesion in tunica media of aortic wall, compared with control group tended to be repressed in sample group. According to the above results, it is assumed that Alismatis Lhizoma has a valid effect on hyperlipidemia. And yet, it needs to make further researches that sample I group showed more significant value than sample II group.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.3
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• pp.625-633
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• 2015

Olive flounder (Parlichthys olivaceus) is a large carnivorous fish that live at coastal area and shallow seas in Korea. It was good texture and clean taste because of a high collagen content and low lipid content. More than 70% of olive flounder annual production was traded alive, consequently processing food product from olive flounder is rare to be towed. This study was conducted to investigate the best method of olive flounder cutlet processing. Clean fillet (headless, skinless and contain no viscera part) of olive flounder were divided into 5 portion. Every 100 g of olive flounder meat was wrapped with vinyl then flatten with meat hammer. Flatten fillet then was coated with wheat flour, and seasoned with salt and pepper. These were then coated with egg wash and bread crumbs. Two different method of processing was to make this olive flounder cutlet. Cutlet-1 was fried for 1 min in olive oil, then kept in polyethylene film vacuum packaging ($20{\times}30{\times}0.05mm$) and stored at $-20^{\circ}C$ for 7 days. After 7 days the cutlet was thawed and heat up in microwave for 2 min (Sample-1). The other proup is cutlet-2, which is directly stored in polyethylene film vacuum packaging at $-20^{\circ}C$ for 7 days then thawed and fried for 1 min in olive oil (Sample-2). The factors such as pH, TBA value, amino-N, free amino acid, chemical composition, color value (L, a, b), texture profile, sensory evaluation and viable bacterial count of the olive flounder cutlet (Sample-1, Sample-2) were measured. From the result of sensory evaluation, Sample-2 showed a little high scores than Sample-1. But there was no significant differences in color, odor, taste, texture and overall acceptance between Sample-1 and Sample-2 products.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.2 no.1
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• pp.1-16
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• 1989

The studies were attempted experimental effects of Jingyochangchooltang (Sample A), Jingyochangchooltang plus Sophorae Semen (Sample B) and Deungyangjingyochangchooltang (Sample C) on analgesia, antipyretic, antiinflammatory action and Tramsport of Intestinal contents in mice. The result of studies were as follows: 1. Analgesia action by Acetic acid method was showed significant effect at all sample groups. 2. Analgesia action by Acetylcholine-HCil method was showed significant effect in sample A group. 3. Analgesia action by Reandall-selitto method was showed significant effect at all sample groups especially sample B group was showed more significant effect from 2 hours to 3 shours. 4. Antipyretic action by yeast method was showed significant effect at all sample groups, especially sample A group and sample C group were showed more significant effect after 6 hours than sample B group. 5. Antiinflammatory action by carrageenine method was showed significant effect at all simple groups. 6. In the intestinal transport, in contrast to control group, sample A group revealed the increasing rate $38.7\%$ and sample B group revealed the increasing rate $47.7\%$. According to the above result, it can be concluded that Jingyochangchooltang, Jingyochangchooltang plus sophorae Semen and Deungyangjingyochangchooltang had a remarkable effect on the treatment of hemorrhoids caused by Pung Yul and inflammation of anus.

• The Journal of Pediatrics of Korean Medicine
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• v.8 no.1
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• pp.1-12
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• 1994

In order to investigate the effects of Insamyangwee Tang on cell-mediated and humoral immune response, solid extract of Insamyangwee Tang (sample A), mixture of individual solid extract of Insamyangwee Tang (sample B) were administered orally for 14 days. The auther used ICR mice having a body weight of about 20-22g as experimental animals dividing them into three groups-Saline, Sample A and Sample B group. All of the mice were sensitized i.v. with $10^8$ sheep red blood cells(SRBC) and challenged i.d. with $10^8$ SRBC 4 days later. Such immune responses as delayed-type hypersensitivity(DTH), rosette forming cells(RFC), hemagglutinin titers(HA titers) and hemolysin titers(HL titers) were measured at 24 hours after challenge. The results were as follow: 1. DTH in Sample A & Sample B group was increased, as compared with Saline group, with satistical significance. 2. RFC in Sample A & Sample B group were increased, as compared with Saline group, with statistical significance. 3. HA titers in Sample A & Sample B group were not increased, as compared with Saline group, with statistical significance. 4. HL titers were increased just only in Sample A group with statistical significance. The inference from the above results is that Sample A group is better than Sample B group, and Insamyangwee Tang enhance the cell-mediated and humoral immune response.

• Journal of Veterinary Clinics
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• v.32 no.1
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• pp.73-77
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• 2015

There has been increasing attention on sample size requirements in peer reviewed medical literatures. Accordingly, a statistically-valid sample size determination has been described for a variety of medical situations including diagnostic test accuracy studies. If the sample is too small, the estimate is too inaccurate to be useful. On the other hand, a very large sample size would yield the estimate with more accurate than required but may be costly and inefficient. Choosing the optimal sample size depends on statistical considerations, such as the desired precision, statistical power, confidence level and prevalence of disease, and non-statistical considerations, such as resources, cost and sample availability. In a previous paper (J Vet Clin 2012; 29: 68-77) we briefly described the statistical theory behind sample size calculations and provided practical methods of calculating sample size in different situations for different research purposes. This review describes how to calculate sample sizes when assessing diagnostic test performance such as sensitivity and specificity alone. Also included in this paper are tables and formulae to help researchers for designing diagnostic test studies and calculating sample size in studies evaluating test performance. For complex studies clinicians are encouraged to consult a statistician to help in the design and analysis for an accurate determination of the sample size.

• THE JOURNAL OF KOREAN ORIENTAL ONCOLOGY
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• v.4 no.1
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• pp.89-110
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• 1998

Yookmijihwangtang has been widely used oriental herb prescriptions, which is healing some discuss that come from insufficiency of innate essence and deficiency of kidney Ki. The meaning of healing discusses tonification of insufficient innate essence and insufficient kidney Ki can be regarded as reinforcement of wholely power of keeping homeostasis, that is correlated with immuno-responsibility which protects subject from outer antigen to keep normal vital condition. This study was aimed to investigate correlative effects of Yookmijihwangtang water abstract on the RBC, WBC, blood CD4+ T helper cell count, blood testosterone, blood cAMP and blood cortisol. 40 Sprague-Dawley male rats were divided into 5 groups(Normal, Control, Sample I, Sample II, Sample III), 6 animals in every group. Normal group was not treated anything, control group was administrated normal saline in the same dosage of Sample I. 3 Sample groups were received some of Yookmijihwangtang water abstract at one time per 24 hours during 5 days in different dosage. Sample I(1/310pack/ml), Sample II(1/62pack/ml), Sample III(1/2.4pack/ml). After finishing treatment, all experimental subjects were killed for blood sample on RBC, WBC, blood CD4+ T helper cell count, spleen CD4+ T helper cell count, axillary lymph node CD4+ T helper cell count. blood cAMP, blood testosterone and blood cortisol. The results were as follows; RBC and WBC were increased in all sample groups. Blood CD4+ T helper cell count(CD4+ T cell count in the blood/whole lymphocyte count in the blood ${\times}100%$) was Normal $46.17{\pm}5.88$, Control $44.50{\pm}4.37$, Sample I $53.00{\pm}2.28$, Sample II $53.83{\pm}3.87$, Sample III $52.17{\pm}2.93$. By the 95% Duncan ANOVA all experimental groups(sample I, Sample II, Sample III) showed slight significant difference from Normal and Control. Blood cAMP(nmol/l) were Normal $1.12{\pm}0.17$, Control $1.16{\pm}0.32$, Sample I $0.46{\pm}0.07$, Sample II $0.44{\pm}0.04$, Sample III $0.54{\pm}0.04$. All experimental groups were singificantly different from both Normal and Control groups(p<0.05). Blood cortisol(nl/ml) were Normal $100.00{\pm}2.00$ Control $90.00{\pm}4.00$, Sample I $440.00{\pm}5.00$, Sample II $520.00{\pm}40.00$, Sample III $470.00{\pm}7.00$. Blood cortisol of all experimental groups were significantly increased(p<0.05). The results suggest that Yookmijihwangtang water abstract could be administrated to patients who have some diseases insufficient essence.

• Journal of Trauma and Injury
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• v.37 no.1
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• pp.67-73
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• 2024

Purpose: Posttraumatic stress disorder (PTSD) is prevalent and is associated with protracted recovery and worse outcomes after injury. This study compared PTSD prevalence using the PTSD Checklist for DSM-5 (PCL-5) with the prevalence of PTSD risk using the Injured Trauma Survivor Screen (ITSS). Methods: Adult trauma patients at a level I trauma center were screened with the PCL-5 (sample 1) at follow-up visits or using the ITSS as inpatients (sample 2). Results: Sample 1 (n=285) had significantly fewer patients with gunshot wounds than sample 2 (n=45) (8.1% vs. 22.2%, P=0.003), nonsignificantly fewer patients with a fall from a height (17.2% vs. 28.9%, P=0.06), and similar numbers of patients with motor vehicle collision (40.7% vs. 37.8%, P=0.07). Screening was performed at a mean of 154 days following injury for sample 1 versus 7.1 days in sample 2. The mean age of the patients in sample 1 was 45.4 years, and the mean age of those in sample 2 was 46.1 years. The two samples had similar proportions of female patients (38.2% vs. 40.0%, P=0.80). The positive screening rate was 18.9% in sample 1 and 40.0% in sample 2 (P=0.001). For specific mechanisms, the positive rates were as follows: motor vehicle collisions, 17.2% in sample 1 and 17.6% in sample 2 (P>0.999); fall from height, 12.2% in sample 1 and 30.8% in sample 2 (P=0.20); and gunshot wounds, 39.1% in sample 1 and 80.0% in sample 2 (P=0.06). Conclusions: The ITSS was obtained earlier than PCL-5 and may identify PTSD in more orthopedic trauma patients. Differences in the frequency of PTSD may also be related to the screening tool itself, or underlying patient risk factors, such as mechanism of injury, or mental or social health.

• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.403-420
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• 1994

An economic design of the $\bar{X}-R$ chart using variable sample size (VSS) scheme is proposed in this paper. In this design the sample size at each sampling time changes according to the values of the previous two sample statistics, sample mean and range. The VSS scheme uses large sample if the sample statistics appear near inside the control limits and smaller sample otherwise. The set of process parameters, such as the sampling interval, control limits and the sample sizes, are chosen to minimize the expected cost per hour. The efficiency of the VSS scheme is compared to the fixed sample size one for cases where there is multiple of assignable causes. Percent reductions of the expected cost in the VSS design are calculated for some given sets of cost parameters. It is shown that the VSS scheme improves the confidence of the procedure and performs statistically better in terms of the number of false alarms and the average time to signal, respectively.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1109-1114
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• 2008

To investigate the effect of sample size on coefficient of consolidation of non-homogeneous soil, the result of a large size consolidation test using a huge undisturbed sample with $1200mm(D){\times}2000mm(H)$ in dimension is compared with that of oedometer test using undisturbed small sample. In addition, test results are compared with those of same test using remold sample. Experimental results show that, due to the lump of sand/silt was mixed in sample, the coefficient of consolidation of undisturbed samples have a difference for each tests. Whereas, the difference of coefficient of consolidation between remolded large and small samples is not found. Because sample size affects the test results, sample must be carefully selected for non-homogeneous soil.