• Communications for Statistical Applications and Methods
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• 제26권2호
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• pp.163-173
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• 2019

Simon's two-stage designs are frequently used in phase II single-arm trials for efficacy studies. A concern of safety studies is too many patients who experience an adverse event. We show that Simon's two-stage designs for efficacy studies can be similarly used to design a two-stage safety study by modifying some of the design parameters. Given the type I and II error rates and the proportion of adverse events experienced in the first stage cohort, we prescribe a procedure whether to terminate the trial or proceed with a stage 2 trial by recruiting additional patients. We study the relationship between a two-stage design with a safety endpoint and an efficacy endpoint as well as use simulation studies to ascertain their properties. We provide a real-life application and a free R package gen2stage to facilitate direct use of two-stage designs in a safety study.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.1037-1040
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• 2004

Sound and vibrations enter every aspect of our daily lives. Some, like music and verbal communications, soothe and relax us; others, such as the noise and vibration from traffic or machinery, can threaten our well being. The Rion Co., Ltd. was eslablished in 1944 as an affiliate of physics and acoustic pioneer, Kobayashi Institute of Physical Research. The RION lineup affords a full line of easy-to handle measuring, recording, and analyzing equipment with innumerable applications for monitoring and maintaining a comfortable environment. RION's concern takes in all manner of sound and vibration. Our activities extend from measuring reverberation time in concert halls and testing the soundproofing characteristics of housing materials to the control and maintenance of machine noise and vibration levels.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.61-62
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• 2023

Promoting energy-efficient retrofit of existing buildings to achieve carbon neutrality by 2050 is critically vital and challenging. The bulk of outdated educational buildings in particular are of grave concern since they are not only have a significant negative impact on the environment but also dangerous to inhabitants'health. This study laid the groundwork for understanding the connection between occupant health and energy efficiency. This study proposes a prioritized strategic GR framework in South Korea's aging preschools. The possible prospects and levels of development in the GR plan are identified by this evaluation. Policy markers, educators, and other key stakeholders may help to create a more sustainable and healthy environment by putting the recommended framework into practice.

• Asian-Australasian Journal of Animal Sciences
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• 제11권2호
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• pp.162-170
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• 1998

The dose response effects of different levels of wheat barn (WB) supplementation to a rice straw based diet has been studied in growing native (Bos indicus) bulls of Bangladesh. Twelve bulls of $266{\pm}29.6kg$ live weight and $32{\pm}9.5$ months old were given either of three diets of ad libitum untreated rice straw alone (T1) or straw supplemented with 2 (T2) or 3 (T3) kg WB. Besides, the experimental animals also received a mineral mixture. In 4 weeks, data were recorded on the intake, digestibility, microbial N (MN) yield, N balance (NB) and growth rate (GR). In the three diets, WB was 0 (T1), 29.6 (T2) and 42 (T3) percent of the total DM intake. With the increasing levels of WB supplementation, the total DM and OM intake increased, but the straw intake decreased linearly. WB supplementation increased the digestibilities of DM, OM and N but had no effect on ADF digestibility. The urinary purine derivative excretion and hence the MN yield increased with WB supplementation. The total MN yield were 7.26 and 35 g/d respectively for 0.2 and 3 kg WB supplementation. However, the efficiency of MN yield was highest (13 g/kg DOMR) at 2 kg WB level. Despite the increase DOM intake, the dietary ME content remain below 6 MJ/kg DM even at 3 kg WB supplementation. The NB were -84,467 and 1,620 mg/kg $W^{0.75}/d$ which were reflected on the GR of -186,346 and 554 g/d for 0, 2 and 3 kg WB supplementation respectively. Depending on the cost effectiveness, on an untreated rice straw diet, WB may be supplemented by up to 3 kg/d (42% of the diet) or more. However, if the maximum utilization of roughage is the main concern, the optimum WB level would probably be around 2 kg (30% of the diet) daily.

• 한국환경과학회지
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• 제6권6호
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• pp.659-670
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• 1997

차량 내부의 높은 휘발성 유기물질 농도와 이들 휘발성 유기물질의 독성 때문에 휘발성 유기물 질에 대한 차량 내부에서의 노출이 주요한 관심을 받고 있다. 본 연구에서는 115회의 도시 지역 (대구 광역시) 출퇴근과 9회의 정차 실험을 통해 상업용 공기정화기의 6 종류 휘발성 유기물질에 대한 제거 효율이 평가되었다. 네 종류의 운전 조건에서 수행된 정차 및 출퇴근 연구 결과, 본 연구에서 이용된 두 개의 시중 시판 차량용 공기정화기는 휘발성 유기물질에 대해 제거 효율이 없는 것으로 나타났다. 벤젠을 제외한 다섯 종류의 휘발성 유기물질의 농도는 최근 차량보다 오래된 차량 내부에서 높게 나타났다 (p<0.05). 본 연구에서 측정된 벤젠과 톨루엔의 평균 농도는 로스앤젤레스에서 측정된 값과 유사하게 나타났고, 그 이외의 미국내 비교지역의 측정 값보다는 높게 나타났다. 휘발성 유기물질에 대한 노출 및 해당 발암 위해성은 차량 내부에서 실외 공기의 약 8배 정도 높게, 그리고 실내 공기의 약 절반 정도로 산정 되었다.

• Nutrition Research and Practice
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• 제5권2호
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• pp.157-162
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• 2011

The importance of dietary intake in the treatment of type 2 diabetes was emphasized. This study was performed to investigate the dietary intakes of Korean type 2 diabetes patients according to the treatment and duration of diabetes and to examine the relationships between their diet and serum lipid profiles. The subjects were 111 type 2 diabetic patients who were treated by medical nutrition therapy only, oral hypoglycemic agents (OHA), or insulin with medical nutrition therapy. Dietary intake was assessed by a registered dietitian using semi-quantitative food frequency questionnaires Comparisons according to treatment type were made using covariance analyses. General linear models identified the independent effects of the different treatments after covarying for age, duration of diabetes, and 2-way interactions. There were no significant differences in age and BMI but was in duration of diabetes according to treatment type in these subjects. Carbohydrate to energy ratio was higher in the OHA group (P < 0.05), whereas the fat to energy ratio was higher in the insulin group for males (P < 0.05). Carbohydrate ($R^2$ = 0.24, P = 0.005) and fat ($R^2$ = 0.26, P = 0.02) to energy ratios were independently associated with the duration of diabetes after covarying for age, sex, treatment, and 2-way interactions. The levels of triglyceride (TG; $R^2$ = 0.32, P = 0.02) and total cholesterol (TC) were associated independently with energy intake and the carbohydrate ($R^2$ = 0.15, P = 0.02) and fat ($R^2$ = 0.15, P = 0.01) to energy ratios, respectively. The concern that the independent association of dietary intake with either duration of diabetes or dietary factors affects blood lipid levels could suggest that specific dietary recommendations may work better for identifiable groups of diabetes patients.

• 한국지역사회생활과학회지
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• 제23권3호
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• pp.255-263
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• 2012

Polybrominated diphenyl ethers (PBDEs) are a group of brominated flame retardants (BFRs), which are used in a variety of consumer products. Several of those are produced in large quantities. Their chemical structure similarities to polychlorinated dibenzo-p-dioxins and polychlorinated biphenyls (PCBs), as well as their toxicity, has been studied. PBDEs are persistent and lipophilic, which results in their bioaccumulation in the fatty tissues of organisms and enrichment throughout food chains. In addition, a number of studies also reported high levels of PBDEs in animals and food resulting from the use of contaminated animal feed Public concern about PBDEs levels in animals and food has been raised. Feed contamination by toxic chemicals has been the cause of the contamination of poultry products. The purpose of this study was to evaluate PBDEs in pig feed to search the origin chase of POPs in pigs. Feed samples were obtained wheat from East Europe, corn from South America and America, soybean meal from Korea, America, South America and India and tallow from Korea. The preparation of samples was based on the EPA method 1614. Instrumental analysis was based on the use of high resolution gas chromatography coupled to high resolution mass spectrometry (HRGC/HRMS). Quantification was carried out by the isotopic dilution method. The analysis of ${\Sigma}PBDEs$ involved 22 PBDE congeners, including BDE-17, 28, 47, 49, 66, 71, 77, 85, 99, 100, 119, 126, 138, 153, 154, 156, 183, 184, 190, 191, 196 and 197.

• Clinical and Experimental Reproductive Medicine
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• 제44권1호
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• pp.22-27
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• 2017

Objective: Azoospermia owing to testicular disorders is the most severe manifestation of male infertility. The main concern for patients with nonobstructive azoospermia (NOA) is the probability of successful sperm retrieval following testicular sperm extraction (TESE). Therefore, the goal of this study was to determine predictive factors correlated with sperm retrieval. Methods: We assessed the testicular histopathological patterns, the choice of TESE surgical procedure, hormone levels, and chromosomal abnormalities in patients with NOA (n=170). The histopathology specimens were analyzed based on the histopathological patterns of hypospermatogenesis, maturation arrest, and Sertoli cell-only syndrome. Results: The mean rate of sperm retrieval was 48.8%. The rate of sperm retrieval was significantly higher in the hypospermatogenesis group than in the other groups (p<0.001). There was a positive correlation between micro-TESE (vs. conventional TESE) and the sperm retrieval rate (odds ratio, 8.077; p<0.01). A logistic regression model demonstrated that high levels of follicle-stimulating hormone (FSH) and small testicular volume were significantly associated with lower chances of successful sperm retrieval. Conclusion: Some parameters, including testicular histopathology patterns, FSH levels, testicular volume, and method of TESE surgery, may be able to predict the chances of obtaining spermatozoa in patients with NOA. However, despite the efficiency of some predictive models, the hope of retrieving any functioning spermatozoa may be sufficient to disregard predictive factors of the success of intracytoplasmic sperm injection in these patients.

• 한국환경보건학회지
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• 제32권2호
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• pp.186-191
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• 2006

Metal contamination of medicinal herbs is of growing concern because of their potential adverse health effects. In this study, metal exposures were estimated and their potential health risks were preliminarily evaluated using available data including metal contamination levels and consumption estimates of herbal medicine in Korea. Consumption and contamination data of 34 medicinal herbs abundantly used in Oriental medicine in Korea were used in this study. Lead, mercury, arsenic, cadmium, cobalt, and chrome were identified as contaminants of potential health concerns. Even based on a conservative exposure scenario, i.e., consuming 5 times more herbal medicine with 95th percentile contamination levels, health risks associated with herbal medicine consumption were estimated to be minuscule. Herbal consumption was 0.3% of the provisional tolerable daily intake levels recommended by Joint Expert Committee on Food Additives (JECFA) of WHO/FAO. However, it should be noted that there are several important assumptions and uncertainties associated with this evaluation: This study was conducted for only 34 types of medicinal herbs of which consumption and metal contamination data were available. In addition, there are no reliable herbal medicine consumption data among Korean population. The pattern and amount of herbal (medicine) consumption in Korea need to be investigated in order to conduct more refined risk assessment associated with metal contamination in medicinal herbs.

• Ocean and Polar Research
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• 제40권3호
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• pp.169-176
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• 2018

Recently, the pop-up satellite archival tag (PSAT) is being used in studies as a method of using satellites for monitoring organisms. Because PSATs are attached directly on the organism being monitored, it is used mostly on larger species since the health of the organism is an important concern. For this reason, PSAT-based surveys are lacking in Korea with no studies on the physiological responses of organisms with PSAT attached. Accordingly, as a basic biomonitoring study using PSAT, the present study investigated the physiological changes in fish in response to the attachment of PSAT. The present study used red seabream (Pagrus major) and Korean rockfish (Sebastes schlegelii) as the experimental fish. The PSAT was attached to the muscle below the experimental fish's dorsal fin using a mono filament (n = 3). To investigate the changes in physiological responses according to PSAT attachment, blood samples were collected from all experimental fish, including the control (n = 3), at 1, 7, 14 and 21 days after the attachment. Upon blood sample collection, whole blood was used to measure hematocrit and hemoglobin levels. After separating the plasma, the separated plasma was used to measure the GOT, GPT, glucose, total protein, and cholesterol levels. Meanwhile, the plasma cortisol, superoxide dismutase, and catalase levels were measured using the ELISA method. The results showed that attaching the tag did not have any impact on the immunity and stress response of the experimental fish. The findings in this study also demonstrated the possibility of using PSAT for studying relatively smaller species living in the coastal waters of Korea.