• Journal of Digital Convergence
• /
• v.12 no.5
• /
• pp.139-148
• /
• 2014

In recent years, computational models using parametric estimation method have been developed and used widely for efficient cost analysis. In this research, by applying experienced data from Guidance and Control Systems in Missile System field, the cost analysis for engineering model and commercial computational model(Price H, HL, M, S) are conducted and its result is analysed, so that the difference between two models and its grounds are apprehended. Comparing the calibrated value of computational model based on the data base of similar equipment and the cost from the engineering estimation, the two results are very close. It means that the credibility of data is enhanced through calibration. Also, for cost analysis of similar components in the future, the method for calibration of the computational models is also examined. When estimating development cost in this research, although many parts have been estimated through uncertain elements, the reliability could have been enhanced by applying computational model which secures objectivity. It is a very reasonable estimation method by utilizing calibration of the computational models based on existing accumulated development data.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.29 no.5
• /
• pp.298-302
• /
• 2016

In this work, $LiMn_2O_4$ and $LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ cathode materials are mixed by some specific ratios to enhance the practical capacity, energy density and cycle performance of battery. At present, the most used cathode material in lithium ion batteries for EVs is spinel structure-type $LiMn_2O_4$. $LiMn_2O_4$ has advantages of high average voltage, excellent safety, environmental friendliness, and low cost. However, due to the low rechargeable capacity (120 mAh/g), it can not meet the requirement of high energy density for the EVs, resulting in limiting its development. The battery of $LiMn_2O_4-LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2$ (50:50 wt%) mixed cathode delivers a energy density of 483.5 mWh/g at a current rate of 1.0 C. The accumulated capacity from $1^{st}$ to 150th cycles was 18.1 Ah/g when the battery is cycled at a current rate of 1.0 C in voltage range of 3.2~4.3 V.

• Korean Journal of Computational Design and Engineering
• /
• v.21 no.3
• /
• pp.252-266
• /
• 2016

An architectural pre-design, which is conducted prior to the architecture design, supports fundamental configuration during the entire AEC project by predicting the cost, demand, etc., of the building, and is therefore gaining importance. In particular, the massing calculation of the pre-design phase should be prioritized, as it is fundamental to architectural outline. However, most architects depend on only their experience and intuition while conceptualizing an integrated framework of design conditions, including the building code and requirements for the massing calculation of the object. Therefore, many difficulties arise in terms of performing appropriate tasks. Thus, the purpose of this study is to implement a knowledge-based BIM for explicitly representing the design knowledge, which is the basis of decision making for an architect while performing the massing calculation. In particular, the 3D knowledge relevant to a project can be provided and accumulated in the massing calculation by the BIM system; this facilitates an integral understanding. Consequently, the approximate result of massing calculation in 3D BIM environment, through both the knowledge-based BIM template and plug-in, can be swiftly provided to the architect. In addition, the architect can invent various alternatives, estimate resulting costs, and reuse the accumulated knowledge in future BIM design processes.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.6
• /
• pp.814-819
• /
• 2010

This paper is presented to study the error minimization of angular velocity for AGV(autonomous ground vehicle). The error minimization of angular velocity is related to localization technique which is the most important technique for autonomous vehicle. Accelerometer, yaw gyro and electronic compass have been used to measure angular velocity. And methods for error minimization of angular velocity have been actively studied through probabilistic methods and sensor fusion for AGVs. However, those sensors still occure accumulated error by mathematical error, system characters of each sensor, and computational cost are increased greatly when several sensor are used to correct accumulated error. Therefore, this paper studies about error minimization of angular velocity that just uses encoder and gyro. To experiment, we use autonomous vehicle which is made by ourselves. In experimental result, we verified that the localization error of proposed method has even less than the localization errors which we just used encoder and gyro respectively.

• Korean Journal of Construction Engineering and Management
• /
• v.8 no.4
• /
• pp.110-118
• /
• 2007

For deciding the owner's budget of the building construction in the predesign stage, the probabilistic methodologies for estimating the cost are often studied, however these parameter-based conceptual estimating methodology has limitation of applying it to the practical business because it hardly can link the design decision-making and the cost estimating and control. Besides if the result of detail estimating after detail design is over the budget, locally and arbitrarily control the level of interior design and fix the design. This research proposed the prototype-based cost estimating model for building interior construction which leads to estimate the interior cost easily linking with design decision-making and supports to evaluate the design alternatives in the schematic design and the design development stage for office buildings. The model divides the building on the design process by Element Breakdown Structure and presents the design alternative by selecting the elements of each room from the database accumulated the historical office buildings' prototypes and estimates the cost. The 2 case studies presented to validate the effectiveness of as the linking tool integrating the design and construction data and applicability to the practical design on the presented prototype-based model.

• Journal of IKEEE
• /
• v.19 no.2
• /
• pp.193-200
• /
• 2015

In this paper, we propose the radiation measuring algorithm and the device composition using CMOS image sensor. The radiation measuring algorithm using CMOS image sensor is based on the radiation particle distinguishing algorithm projected to the CMOS image sensor and accumulated and average number of pixels of the radiation particles projected to dozens of images per second with CMOS image sensor. The radiation particle distinguishing algorithm projected to the CMOS image sensor measures the radiation particle images by dividing them into R, G and B and adjusting the threshold value that distinguishes light intensity and background from the particle of each image. The radiation measuring algorithm measures radiation with accumulated and average number of radiation particles projected to dozens of images per second with CMOS image sensor according to the preset cycle. The hardware devices to verify the suggested algorithm consists of CMOS image sensor and image signal processor part, control part, power circuit part and display part. The test result of radiation measurement using the suggested CMOS image sensor is as follows. First, using the low-cost CMOS image sensor to measure radiation particles generated similar characteristics to that from measurement with expensive GM Tube. Second, using the low-cost CMOS image sensor to measure radiation presented largely similar characteristics to the linear characteristics of expensive GM Tube.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.35 no.6
• /
• pp.631-638
• /
• 2022

Microgrid, which enables the production and consumption of electricity to be done independently on a small scale, has been studied on one of the solutions of reinforcement for flexibility of electronic system. This study examined the application effect of new microgrid by applying hybrid battery in electric power storage device. We designed the system to highlight the advantage of each battery and complement the disadvantage by using hybrid system with Lithium-ion battery and interval Redox flow battery. It runs with lithium-ion battery during the initial startup while the Redox flow battery operates for a long time at the end of excessive period, and it enables a discharge of Lithium-ion and Redox flow battery at the same time when the load has a large output. We chose Maldives as a subject of this study for organizing and optimizing independent microgrid. Maldives is the country to accomplish 100% domestic electricity in South Asia, but the whole electric power is supplied through diesel generation imported fossil fuel. We organized and optimized microgrid for energy independence on Malahini island to solve Maldives energy cost problem and global energy environment matters. We analyzed the daily power supply and accumulated the power supply from September 18, 2018~February 11, 2019. The accumulated power supply was about 120.4 MWh and the daily power supply was about 800~1000 kWh. Based on the collected information, we divided the cases into three models which are only diesel generator, solar generator as well as diesel generator, and solar+ESS+diesel generator. We analyzed the amount of oil consumption compared to the cost of construction and power output. The result showed that solar+ESS+diesel generator was most economically feasible. As well, we obtained that our considering hybrid battery system reduced the fuel consumption for diesel power generation about 10~15%.

• Korea Journal of Hospital Management
• /
• v.23 no.3
• /
• pp.28-38
• /
• 2018

Purpose: To evaluate the medical expenditures for prostate cancer patients, including out-of-pocket costs, and compared the costs between androgen deprivation therapy and radical prostatectomy treatment. Methodology: This study combined clinical data from 357 prostate cancer patients from the Smart Prostate Cancer Database and the medical expenditure data from the claims and cost databases. We used the independent two-sample t-tests to compare androgen deprivation therapy and radical prostatectomy. Multivariable logistic regression analysis was conducted to identify determining factors for androgen deprivation therapy and radical prostatectomy treatments. Findings: The medical costs of androgen deprivation therapy treatment were much lower than radical prostatectomy treatment at the one year and remained lower until the fourth-year. However, after four years, the accumulated medical expenditures of androgen deprivation therapy become significantly higher than radical prostatectomy treatment. Patients with a higher cancer stage and older age had higher chances of being treated using androgen deprivation therapy treatment than radical prostatectomy treatment. Practical Implications: Our results show that early detection of cancer reduces the treatment cost for both patients and insurance payers. It also demonstrates that cost comparisons should be conducted over long periods of time in order to most accurately assess the costs.

• Journal of Korean Society for Geospatial Information Science
• /
• v.10 no.4 s.22
• /
• pp.85-93
• /
• 2002

Since the National Geographic Information System(NGIS) project of 1995, the geographic information projects have been promoted in various areas such as central and local governments. In the fact that large scale budget has been invested to geographic information projects as a national policy, the cost-benefit analysis would be essential to enhance the efficiency of the resource allocation. In this circumstance, this study analyzes the costs and benefits of geographic information produced by NGI(National Geography Institute). As a result of the cost-benefit analysis, the total amount of benefits were estimated approximately 620 million dollars and the accumulated ratio of the cost to benefit was 1 to 4.4. Also, the internal ratio of the benefit was 38%, which justified the large scale investment. In case of adding qualitative benefits which can not be measured in a quantitative term, the overall benefits from using such geographic information would be much higher than quantitative benefits. Further research work is required for more objective verification of the large scale national project such as building nationwide geographic information.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2021.06a
• /
• pp.148-149
• /
• 2021

Food waste has increasingly become a global issue of concern among the researchers and policymakers due to its significant environmental and economic impacts, and other associated unsustainable use of resources, including water resources. While food wastage occurs at each stage of the supply chain with food loss at the upstream and food waste at the downstream, the impacts of food waste occurring at the consumption side are enormous due to the accumulated added values. In this study, the embedded water resources, greenhouse gas emissions, and economic loss of household food waste were investigated. The primary granular data of household food waste was collected through direct sampling from 218 selected households of the Buk-gu community in Daegu, South Korea from July 2019 to May 2020. The water footprint, which was based on the water footprint concept, i.e., indirect water use, and GHG emission potential factor for each of the food items were adopted from the literature, while the retail prices and disposal cost were used to assess the economic cost of wasted food items. The water footprint, GHG emission associated with environmental impacts, and the economic cost of 42 major identified wasted food items were conducted. The findings showed that an average of 0.73 ± 0.06 kg/household/day edible food waste was generated among the sampled households, with leafy vegetable, watermelon, and rice responsible for 10, 9, and 4%, respectively, of the total weight of the 42 food wasted items. The water footprint and environmental impact of the household food waste resulted in 0.46 ± 0.04 m³ and 0.71±0.05 kg CO2eq, respectively. Beef, pork, poultry, and rice accounted for 52, 9, 5, and 4% of the total water footprint, while beef, pork, rice, tofu/cheese had 52, 8, 6, and 6% of the total emissions, respectively, embedded in the food wasted. Furthermore, the average estimated economic cost associated with wasted food items was 3855.93±527.27 Korean won, with beef, fish, and leafy vegetable responsible for 21, 13, and 10%, respectively, of the total economic cost. A combined assessment using water-environmental-economic nexus indicated that animal-based food had the highest footprint impacts, with beef, pork, and poultry indicating high indices of 0.3, 0.08, and 0.06 respectively, on a scale of 0 to 1, compared to corn and lettuce with lowest impacts of 0.02. Other food items had moderate impact values ranging from 0.03 to 0.05. This study, therefore, provides insight into the enormity of environmental and economic implications of household food waste among Korean households.