• Composites Research
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• 제32권6호
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• pp.307-313
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• 2019

Triboelectric nanogenerators (TENGs)는 정전기 기반의 마찰 전기 발전기로써 간단한 구조로 저비용, 대면적으로 손쉽게 활용할 수 있는 기술이다. 본 연구에선 생활 용품을 활용하여 화학적 결합 및 SEM image로써 분석을 하고 C-C/C-H/C-O/C=O bonding에 따라 bonding 조성비에 따라 C-C bonding의 비율이 클수록 음전하, C-H bonding 비율이 클수록 양전하 대전체가 되는 것을 확인하였다. 그러한 특성을 가지고 최적 생활용품을 활용하여 정전 출력 실험을 했을 때 최대 210 V, 14.6 ㎂, 9.83 mW의 출력을 얻었다. 최종적으로, 랩과 마그네틱 노트를 이용해 97개의 Light Emitting Diodes (LEDs)를 점등할 수 있었다.

• Computers and Concrete
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• 제17권6호
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• pp.787-799
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• 2016

Climate anomalies in recent years, numerous natural disasters caused by landslides and a large amount of entrained sands and stones in Taiwan have created significant disasters and greater difficulties in subsequent reconstruction. How to respond to these problems efficaciously is an important issue. In this study, the sands and stones were doped with recycled materials (waste LCD glass sand, slag powder), and material was mixed for recycled ready-mixed soil. The study is based on security and economic principles, using flowability test to determine the water-binder ratio (W/B=2.4, 2.6, and 2.8), a fixed soil: sand ratio of 6:4 and a soil: sand: glass ratio of 6:2:2 as fine aggregate. Slag (at concentrations of 0%, 20%, and 40%) replaced the cement. The following tests were conducted: flowability, initial setting time, unit weight, drop-weight and compressive strength. The results show that the slump values are 220 -290 mm, the slump flow values are 460 -1030 mm, and the tube flow values are 240-590 mm, all conforming to the objectives of the design. The initial setting times are 945-1695 min. The unit weight deviations are 0.1-0.6%. The three groups of mixtures conform to the specification, being below 7.6 cm in the drop-weight test. In the compressive strength test, the water-binder ratios for 2.4 are optimal ($13.78-17.84kgf/cm^2$). The results show that Recycled ready-mixed soil materials (RRMSM) possesses excellent flowability. The other properties, applied to backfill engineering, can effectively save costs and are conducive to environmental protection.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7701-7706
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• 2013

Background: In a prospective cohort study of antiemetic therapy conducted in Malaysia, a total of 94 patients received low emetogenic chemotherapy (LEC) with or without granisetron injections as the primary prophylaxis for chemotherapy-induced nausea and vomiting (CINV). This study is a retrospective cost analysis of two antiemetic regimens from the payer perspective. Materials and Methods: This cost evaluation refers to 2011, the year in which the observation was conducted. Direct costs incurred by hospitals including the drug acquisition, materials and time spent for clinical activities from prescribing to dispensing of home medications were evaluated (MYR 1=$0.32 USD). As reported to be significantly different between two regimens (96.1% vs 81.0%; p=0.017), the complete response rate of acute emesis which was defined as a patient successfully treated without any emesis episode within 24 hours after LEC was used as the main indicator for effectiveness. Results: Antiemetic drug acquisition cost per patient was 40.7 times higher for the granisetron-based regimen than for the standard regimen (MYR 64.3 vs 1.58). When both the costs for materials and clinical activities were included, the total cost per patient was 8.68 times higher for the granisetron-based regimen (MYR 73.5 vs 8.47). Considering the complete response rates, the mean cost per successfully treated patient in granisetron group was 7.31 times higher (MYR 76.5 vs 10.5). The incremental cost-effectiveness ratio (ICER) with granisetron-based regimen, relative to the standard regimen, was MYR 430.7. It was found to be most sensitive to the change of antiemetic effects of granisetron-based regimen. Conclusions: While providing a better efficacy in acute emesis control, the low incidence of acute emesis and high ICER makes use of granisetron as primary prophylaxis in LEC controversial.

• 한국환경과학회지
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• 제32권11호
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• pp.821-831
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• 2023

Recently, landscaping construction has played a significant role in enhancing the quality of life for citizens by creating and maintaining outdoor spaces. However, landscaping projects vary in material procurement depending on the contracting method, and they also present various challenges in defect occurrence and defect rectification due to their specialized nature. In this study, we classified different types of projects based on material procurement ratios and conducted on-site assessments of defect status by specific processes. We also analyzed the itemization of material ratios and defect rectification costs. The results revealed it was found that projects with a higher proportion of government-provided materials had the poorest defect status in terms of planting works and also incurred the highest defect rectification costs. Moreover, conflicts concerning the responsibility for defects arose. Currently, there are no specific guidelines for setting standards for the proportion of government-provided materials in landscaping construction contracts. Furthermore, there is ambiguity in the management of defect rectification. Therefore, it is necessary to establish a systematic landscaping construction contracting framework by providing institutional guidelines tailored to local governments or the circumstances of contracting entities and to conduct thorough reviews of construction processes.

• 지질공학
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• 제26권4호
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• pp.485-495
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• 2016

본 연구에서는 방파제 하부지반을 저치환율 재료로 보강 및 개량하기 위한 치환율과 재하중 방치기간을 확률론적 최적화 기법을 이용하여 분석하였다. 해석에 필요한 확률변수의 불확실성을 최소화하기 위하여 사전자료를 활용한 베이지안 갱신결과 최대 39.8% 포인트까지 불확실성이 감소하였고, 특히 사전함수의 표본수가 더 많은 구간의 감소폭이 컸다. 치환율 결정을 위하여 저치환율 단면 중 15~40% 범위에서 일계신뢰도법 및 몬테카를로 시뮬레이션 방법에 의해 해석한 결과 목표파괴확률을 만족하는 치환율은 심층고결처리 및 쇄석다짐말뚝 구간에서 각각 20% 및 25% 이상으로 나타났다. 치환율에 대한 최적화를 위하여 생애주기비용 분석을 실시한 결과 목표파괴확률을 만족하는 범위 내에서 최적 치환율이 산정되었으며, 두 구간에서 각각 20% 및 30%가 가장 경제적인 것으로 결정되었다. 재하중의 방치기간에 대한 확률론적 해석결과 3개월 이상인 경우 모두 목표파괴확률을 만족하는 것으로 나타났다.

• International Journal of Concrete Structures and Materials
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• 제8권4호
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• pp.301-307
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• 2014

Rice husk ash (RHA) is classified as a highly reactive pozzolan. It has a very high silica content similar to that of silica fume (SF). Using less-expensive and locally available RHA as a mineral admixture in concrete brings ample benefits to the costs, the technical properties of concrete as well as to the environment. An experimental study of the effect of RHA blending on workability, strength and durability of high performance fine-grained concrete (HPFGC) is presented. The results show that the addition of RHA to HPFGC improved significantly compressive strength, splitting tensile strength and chloride penetration resistance. Interestingly, the ratio of compressive strength to splitting tensile strength of HPFGC was lower than that of ordinary concrete, especially for the concrete made with 20 % RHA. Compressive strength and splitting tensile strength of HPFGC containing RHA was similar and slightly higher, respectively, than for HPFGC containing SF. Chloride penetration resistance of HPFGC containing 10-15 % RHA was comparable with that of HPFGC containing 10 % SF.

• Asian Pacific Journal of Cancer Prevention
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• 제16권18호
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• pp.8265-8270
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• 2016

Purpose: A cost-utility analysis was performed to assess the cost-utility of neoadjuvant chemotherapy regimens containing doxorubicin and cyclophosphamide (AC) versus paclitaxel and gemcitabine (PG) for locally advanced breast cancer patients in Iran. Materials and Methods: This cross-sectional study in Namazi hospital in Shiraz, in the south of Iran covered 64 breast cancer patients. According to the random numbers, the patients were divided into two groups, 32 receiving AC and 32 PG. Costs were identified and measured from a community perspective. These items included medical and non-medical direct and indirect costs. In this study, a data collection form was used. To assess the utility of the two regimens, the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core30 (EORTC QLQ-C30) was applied. Using a decision tree, we calculated the expected costs and quality adjusted life years (QALYs) for both methods; also, the incremental cost-effectiveness ratio was assessed. Results: The results of the decision tree showed that in the AC arm, the expected cost was 39,170 US$ and the expected QALY was 3.39 and in the PG arm, the expected cost was 43,336 dollars and the expected QALY was 2.64. Sensitivity analysis showed the cost effectiveness of the AC and ICER=-5535 US$. Conclusions: Overall, the results showed that AC to be superior to PG in treatment of patients with breast cancer, being less costly and more effective.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8993-9004
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• 2014

Background: The incidence rate and the treatment costs of hepatocellular carcinoma (HCC) are high, especially in Thailand. Previous studies indicated that early detection by a surveillance program could help by down-staging. This study aimed to compare the costs and health outcomes associated with the introduction of a HCC surveillance program with no program and to estimate the budget impact if the HCC surveillance program were implemented. Materials and Methods: A cost utility analysis using a decision tree and Markov models was used to compare costs and outcomes during the lifetime period based on a societal perspective between alternative HCC surveillance strategies with no program. Costs included direct medical, direct non-medical, and indirect costs. Health outcomes were measured as life years (LYs), and quality adjusted life years (QALYs). The results were presented in terms of the incremental cost-effectiveness ratio (ICER) in Thai THB per QALY gained. One-way and probabilistic sensitivity analyses were applied to investigate parameter uncertainties. Budget impact analysis (BIA) was performed based on the governmental perspective. Results: Semi-annual ultrasonography (US) and semi-annual ultrasonography plus alpha-fetoprotein (US plus AFP) as the first screening for HCC surveillance would be cost-effective options at the willingness to pay (WTP) threshold of 160,000 THB per QALY gained compared with no surveillance program (ICER=118,796 and ICER=123,451 THB/QALY), respectively. The semi-annual US plus AFP yielded more net monetary benefit, but caused a substantially higher budget (237 to 502 million THB) than semi-annual US (81 to 201 million THB) during the next ten fiscal years. Conclusions: Our results suggested that a semi-annual US program should be used as the first screening for HCC surveillance and included in the benefit package of Thai health insurance schemes for both chronic hepatitis B males and females aged between 40-50 years. In addition, policy makers considered the program could be feasible, but additional evidence is needed to support the whole prevention system before the implementation of a strategic plan.

• 한국농공학회논문집
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• 제49권4호
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• pp.43-49
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• 2007

The reinforced concrete slab is one of main structure members in the construction industry sector. However, most of researches regarding to RC slabs have been focused on two-dimensional Mindlin-type plate element on the basis of laminated plate theory since three-dimensional solid element has a lot of difficulties in finite element formulation and costs in CPU time. In reality, the RC slabs are subjected to dynamic loads like a heavy traffic vehicle load, and thus should insure the safety from the static load as well as dynamic load. Once we can estimate the dynamic behaviour of RC slabs exactly, it will be very helpful for design of it. In this study, the 20-node solid element has been used to analyze the dynamic characteristics of RC slabs with clamped edges. The elasto-visco plastic model for material non-linearity and the smeared crack model have been adopted in the finite element formulation. The applicability of the proposed finite element has been tested for dynamic behaviour of RC slabs with respect to characteristics of concrete materials in terms of cracking stress, crushing strain, fracture energy and Poisson's ratio. The effect on dynamic behaviour is dependent on not crushing strain but cracking stress, fracture energy and Poisson's ratio. In addition to this, it is shown the damping phenomenon of RC slabs has been identified from the numerical results by using Rayleigh damping.

• 기술사
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• 제14권2호
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• pp.5-11
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• 1981

This analysis has been conducted for 8 chemical plants built in Korea during 1975-1976 and the results have been compared with those in U.S.A. observed by Kenneth M. Guthrie. Equipment and materials supplied by domestic makers are limited in activity field and occupy only 12% of all equipment and material cost. However, unit costs of most materials supplied by home such as cement, steel, cables and carbon steel pipes, etc. being relatively cheaper than those of abroad, their effects on material-to-equipment ratios are apparent. There is a deep difference in labor wage rates between Korea and U.S.A. as much as 16 times. However, the labor productivity observed in these model projects is in the range of 1.1-1.4 to the Gulf Coast, U.S.A. during the same period. And this low wage rate and relatively high productivity have the greatest influence on deviation of Korean cost structure from that of U.S.A. In these model projects, engineering and construction management was conducted by foreign contractors (mostly U.S.A.), and the resulting project indirect cost amounts to 7.5 times as high as most cases executed by Korean contractors alone. Weighted percentage of each component and L/M-ratio by activities of direct field cost derived from this analysis are shown in detail in Tables 2 and 5 to provide a basis for futher study and comparison.