• 제목/요약/키워드: Pre-Feasibility Study

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CASH FLOW FORECASTING IN CONSTRUCTION PROJECT (건설공사에서의 현금흐름 예측)

  • Park Hyung-Keun
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • autumn
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    • pp.35-41
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    • 2002
  • This research introduces the development of a project-level cash flow forecasting model in construction stage based on the planned earned value and the cost from a general contractors view on a jobsite. Most previous models have been developed to assist contractors in their pre-tendering or planning stage cash flow forecasts. The critical key to cash flow forecasting at the project level is how to build a cash-out model. The basic concept is to use moving weights of cost categories in a budget over project duration. The cost categories are classified to compile resources with almost the same time lags that are based on contracting payment conditions and credit times given by suppliers or venders. For cash-in, net planned monthly-earned values are simply transferred to the cash-in forecast, to be applied there with billing time and retention money. Validation of the model involves applying data from on-going 4 projects in progress for 12 months. Based on the results of the comparative analyses through the simulation of the proposed model and the existing models, the proposed model is more accurate, flexible and simpler than traditional models to the employee of construction jobsite who is not oriented financial knowledge.

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Development and Evaluation of a Patient-Reported Outcome (PRO) Scale for Breast Cancer

  • Zhang, Jun;Yao, Yu-Feng;Zha, Xiao-Ming;Pan, Li-Qun;Bian, Wei-He;Tang, Jin Hai
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.18
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    • pp.8573-8578
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    • 2016
  • Background: This study was guided by principles of the theoretical system of evidence-based medicine. In particular, when searching for evidence of breast cancer, a measuring scale is an instrument for evaluating curative effects in accordance with the laws and characteristics of medicine and exploring the establishment of a system for medically assessing curative effects. At present, there exist few tools for evaluating curative effects. Patient-reported outcomes (PROs) refer to outcomes directly reported by patients (without input or explanations from doctors or other intermediaries) with respect to all aspects of their health. Data obtained from PROs provide evidence of treatment effects. Materials and Methods: In accordance with the tenets of theoretical medicine and ancient medical theory regarding breast cancer, principles for developing a PRO scale were established, and a theoretical model was developed and a literature review was performed, items from this pool were combined and split, and an initial scale was constructed. After a pilot survey and additional modifications, a pre-questionnaire scale was formed and used in a field investigation. After the application of statistical methods, the item pool was used to create a formal scale. The reliability, validity and feasibility of this formal scale were then assessed. Results: In a clinical investigation, 479 responses were recovered, with an acceptance rate of 95%. a combination of various methods was employed, and the items that were selected by all methods or more than half of the methods were employed in the questionnaire. In these cases, the screening methods were combined with certain features of the item, A total of four domains and 38 items were reserved. The reliability analysis indicated that the PRO scale was relatively reliable. Conclusions: Scientific assessment proved that the proposed scale exhibited good reliability and validity. This scale was readily accepted and could be used to assess the curative effects of medical therapy. However, given the limited scope of this investigation, the capacity for adapting this scale to incorporate other theories could not be determined.

A Study on the Improved Parity Check Receiver for the Extended m-sequence Based Multi-code Spread Spectrum System with Code Set Partitioning and Constant Amplitude Precoding (코드집합 분할 방식의 확장 m-시퀀스 기반 정진폭 멀티코드 대역확산 통신 시스템을 위한 개선된 패리티 검사 기반 수신기에 관한 연구)

  • Han, Jun-Sang;Kim, Dong-Joo;Kim, Myoung-Jin
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.8
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    • pp.1-11
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    • 2012
  • The multi-code spread spectrum communication system, which spreads data bit stream by multiplexing orthogonal codes, can transmit data in high rate. However it needs the high-cost good linear amplifier because of the multi-level output signal. In order to overcome this drawback several systems making the amplitude of output signal constant with Walsh codes have been proposed. Recently constant amplitude pre-coded multi-code spread spectrum systems using extended m-sequence have been proposed. In this paper we consider an extended m-sequence based constant amplitude multi-code spread spectrum system with code set partitioning. By grouping the orthogonal codes into 4 subsets, not only is the computational complexity of the transceiver reduced but BER performance also improves. It has been shown that parity checking on four detected codes at the receiver can correct code detection error and result in BER performance enhancement. In this paper we propose a improved parity check receiver. We carried out computer simulation to verify feasibility of the proposed algorithm.

A Study for SCR Catalyst Reduction in Fast SCR Using Oxidation Catalyst (산화촉매를 이용한 Fast SCR에서의 SCR 촉매 저감 연구)

  • Lee, Jae Ok;Lee, Dae Hoon;Song, Young-Hoon;Oh, Dong-Kyu;Seo, Jung-Wook
    • Applied Chemistry for Engineering
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    • v.24 no.3
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    • pp.333-336
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    • 2013
  • Experimental investigation to estimate the feasibility of fast selective catalytic reduction (SCR) or oxidation catalyst combined ammonia SCR system to abate NOx in low temperature condition ($150{\sim}250^{\circ}C$) is reported. Because the conversion of NO to $NO_2$ is pre-requisite of the fast SCR process, the effect of the amount of oxidation catalyst to NO conversion to $NO_2$ was tested. 37, 45 and 51% of conversion rates were obtained for the OCV of 563000, 375000 and 281000 h, respectively. $De-NO_x$ performance in the case of $NO_2/NO_x$ ratio of 45% showed the best result in all tested temperature conditions. Comparison of the fast SCR and standard SCR with the condition of $NO_2/NO_x$ ratio of 45%, $200{\sim}250^{\circ}C$ and space velocity of 10000~30000 h showed that the fast SCR does not show much difference according to the variance of space velocity. Also it was shown that using the fast SCR, the volume of SCR catalyst can be reduced less than half of the standard SCR condition by increasing space velocity without the loss of $De-NO_x$ performance.

Application Analysis of GIS Based Distributed Model Using Radar Rainfall (레이더강우를 이용한 GIS기반의 분포형모형 적용성 분석)

  • Park, Jin-Hyeog;Kang, Boo-Sik;Lee, Geun-Sang
    • Journal of Korean Society for Geospatial Information Science
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    • v.16 no.1
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    • pp.23-32
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    • 2008
  • According to recent frequent local flash flood due to climate change, the very short-term rainfall forecast using remotely sensed rainfall like radar is necessary to establish. This research is to evaluate the feasibility of GIS-based distributed model coupled with radar rainfall, which can express temporal and spatial distribution, for multipurpose dam operation during flood season. $Vflo^{TM}$ model was used as physically based distributed hydrologic model. The study area was Yongdam dam basin ($930\;km^2$) and the 3 storm events of local convective rainfall in August 2005, and the typhoon.Ewiniar.and.Bilis.collected from Jindo radar was adopted for runoff simulation. Distributed rainfall consistent with hydrologic model grid resolution was generated by using K-RainVieux, pre-processor program for radar rainfall. The local bias correction for original radar rainfall shows reasonable results of which the percent error from the gauge observation is less than 2% and the bias value is $0.886{\sim}0.908$. The parameters for the $Vflo^{TM}$ were estimated from basic GIS data such as DEM, land cover and soil map. As a result of the 3 events of multiple peak hydrographs, the bias of total accumulated runoff and peak flow is less than 20%, which can provide a reasonable base for building operational real-time short-term rainfall-runoff forecast system.

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Simultaneous Treatment of Sewage Sludge and Food Wastewater Using Combined Digestion Process (혼합 소화공정을 통한 하수 슬러지와 음폐수 병합 처리)

  • Ha, Jeong Hyub;Park, Jong Moon
    • Applied Chemistry for Engineering
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    • v.28 no.5
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    • pp.581-586
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    • 2017
  • In this study, in order to find the feasibility of thermophilic biological pre-treatment for the co-digestion of food wastewater and sewage sludge, digestion efficiency of the combined thermophilic aerobic and mesophilic anaerobic process and its effect on methane production were investigated. Also, a lab-scale co-digestion process was operated to observe parameter changes according to the increase of organic loading rates using different dilution ratios of distilled water and food wastewater (1/3 [Run I], 2/3 [Run II] in addition to using the raw food wastewater [Run III]). The results indicated that co-digestion process maintained quite stable and constant pH during entire experiments. With regard to VS removal, the higher removal was observed in the combined process and the removal efficiency was 52.24% (Run I), 66.59% (Run II) and 72.53 (Run III), respectively. In addition, the combined process showed about an 1.6-fold improved methane production rate and significantly higher methane yield than that of using single anaerobic digestion process.

The Present Status and Vision of Virtual Construction System Development (가상 건설 시스템 개발 현황과 비전)

  • Kim, Jae-Jun;Choi, Cul-Ho;Shin, Hyun-Mok;Jin, Sang-Yoon;Lee, Kwang-Myung
    • Proceedings of the Korean Institute Of Construction Engineering and Management
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    • 2008.11a
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    • pp.170-175
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    • 2008
  • The research team for the virtual construction development was established with the support of Korea Ministry of Construction and Transportation, and KICTEP (Korea Institute of Construction and Transportation Technology Evaluation and Planning). Its aims are to develop system that is to improve productivity & quality, to create a higher value-added business, and to cultivate international competitiveness in the construction industry. The virtual construction system is a design, engineering, and construction management information system that allows the project participants to effectively share the information throughout the construction life cycle with the support of 3D and design information. To achieve this, the research team focuses on developing several systems. First, the team focuses on developing for the pre-planning, the structural engineering, MEP, and the 3D based estimation system. Second, they focus on developing a simulation system for the construction process planning and feasibility study with help of the virtual reality technologies. Third, they focus on developing the CPLM (Construction Project Life-cycle Management) system for managing construction project data, and the decision support system that makes the collaboration among the project participants based on 3D technologies and information. We also focus on developing the SDAI (Standard Data Access Interface), the localized guideline for 3D design, and a training program. In addition, we focus on developing the undeveloped area of the commercial system and building an environment that can support the communication and collaboration in the construction life-cycle rather than developing the existing and commercialized system.

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Evaluation of Field Application of Portable Near Infrared Reflectance Spectrometer (NIRS) for Quality Evaluation of Italian Ryegrass Silages (신속한 이탈리안라이그라스 사일리지의 품질평가를 위한 소형 근적외선분광기(NIRS)의 현장 적용성 평가)

  • Park, Hyung-Soo;Lee, Sang-Hoon;Kim, Jong-Gun;Choi, Ki-Choon;Seo, Sung;Kim, Won-Ho;Lee, Hyo-Won;Lim, Young-Chul
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.31 no.4
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    • pp.415-422
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    • 2011
  • This study evaluated the feasibility of using a portable near infrared reflectance spectrometer working in the 900~1,600 nm range for the measurement of quality-related parameters (moisture, pH, Acid detergent fiber (ADF), Neutral detergent fiber (NDF), Crude protein (CP), lactic acid) in intact silage. The calibration result for the Phazir (handheld, Polychromix) was compared with the result for the Spectrastar (Lab. based, Unity). A total of 67 Italian ryegrass silages were used to build calibration models using different spectral signal pre-treatments and the partial least squares regression (PLS) method. The good calibration statistics in two instruments was obtained for moisture content of Italian ryegrass silages with over $R^2$ = 0.95. The Phazir spectrometer was less accurate in measuring of ADF, NDF and CP contents. The Spectrastar instrument yielded greater precision for pH and lactic acid content; statistic values were over $R^2$ = 0.82 and the standard error of calibration (SEC) = 0.21% and 0.24%. Thus, the NIR measurement of forage quality in the field by portable NIR analyzers was shown not to be feasible, but additional investigations are required to discern the key instrumental and operational parameters that may influence the portable NIR measurement.

A Proposal for the Design of Augmented Reality Reading Activity Application and Class Model Based On Nuri Curriculum (누리과정을 기반으로 한 증강현실 독후활동 애플리케이션 및 수업 모형 설계 제안)

  • Seo-Young Kim;Tae-Woo Kim;Kyung-Up Lee;Yu-Bin Joe;Jung-Yi Kim
    • The Journal of the Convergence on Culture Technology
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    • v.9 no.1
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    • pp.355-360
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    • 2023
  • Recently, with the development of digital, children are exposed to a lot of media media. Reading activity decreases, making it difficult to acquire information from books or organize and remember acquired information. Since education with augmented reality increases children's participation and immersion in learning, we proposed a reading activity application with augmented reality technology to increase children's reading interest and creativity. In addition, based on the five nurturing processes, we designed a play-oriented reading activity for the application. In addition to the application suggestions, we designed a play-centered lesson model so that it can be used in actual lessons. In order to analyze the conceptual thinking framework according to the lesson model design, we visited an actual daycare center and conducted a class attended by an expert. Experts who participated were asked to fill out a pre-produced questionnaire to review the suitability of the reading activity class model and operation, and the feasibility was examined. Our lesson model design was based on limited book content, and due to ethical concerns, large-scale experiments with children could not be conducted, so the results of the study are not representative of the whole. However, it is significant that the possibility of running a new reading activity class based on the Nuri course has been examined and proposed.

Pre- and Immediate Post-Kasai Portoenterostomy Shear Wave Elastography for Predicting Hepatic Fibrosis and Native Liver Outcomes in Patients With Biliary Atresia

  • Haesung Yoon;Kyong Ihn;Jisoo Kim;Hyun Ji Lim;Sowon Park;Seok Joo Han;Kyunghwa Han;Hong Koh;Mi-Jung Lee
    • Korean Journal of Radiology
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    • v.24 no.5
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    • pp.465-475
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    • 2023
  • Objective: To evaluate the feasibility of ultrasound shear wave elastography (SWE) for predicting hepatic fibrosis and native liver outcomes in patients with biliary atresia. Materials and Methods: This prospective study included 33 consecutive patients with biliary atresia (median age, 8 weeks [interquartile range, 6-10 weeks]; male:female ratio, 15:18) from Severance Children's Hospital between May 2019 and February 2022. Preoperative (within 1 week from surgery) and immediate postoperative (on postoperative days [PODs] 3, 5, and 7) ultrasonographic findings were obtained and analyzed, including the SWE of the liver and spleen. Hepatic fibrosis, according to the METAVIR score at the time of Kasai portoenterostomy and native liver outcomes during postsurgical follow-up, were compared and correlated with imaging and laboratory findings. Poor outcomes were defined as intractable cholangitis or liver transplantation. The diagnostic performance of SWE in predicting METAVIR F3-F4 and poor hepatic outcomes was analyzed using receiver operating characteristic (ROC) analyses. Results: All patients were analyzed without exclusion. Perioperative advanced hepatic fibrosis (F3-F4) was associated with older age and higher preoperative direct bilirubin and SWE values in the liver and spleen. Preoperative liver SWE showed a ROC area of 0.806 and 63.6% (7/11) sensitivity and 86.4% (19/22) specificity at a cutoff of 17.5 kPa for diagnosing F3-F4. The poor outcome group included five patients with intractable cholangitis and three undergoing liver transplantation who showed high postoperative liver SWE values. Liver SWE on PODs 3-7 showed ROC areas of 0.783-0.891 for predicting poor outcomes, and a cutoff value of 10.3 kPa for SWE on POD 3 had 100% (8/8) sensitivity and 73.9% (17/23) specificity. Conclusion: Preoperative liver SWE can predict advanced hepatic fibrosis, and immediate postoperative liver SWE can predict poor native liver outcomes in patients with biliary atresia.