• Asian Pacific Journal of Cancer Prevention
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• v.17 no.1
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• pp.95-100
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• 2016

Background: Survival time of lymphoma patients can be estimated with the help of microarray technology. In this study, with the use of iterative Bayesian Model Averaging (BMA) method, survival time of Mantle Cell Lymphoma patients (MCL) was estimated and in reference to the findings, patients were divided into two high-risk and low-risk groups. Materials and Methods: In this study, gene expression data of MCL patients were used in order to select a subset of genes for survival analysis with microarray data, using the iterative BMA method. To evaluate the performance of the method, patients were divided into high-risk and low-risk based on their scores. Performance prediction was investigated using the log-rank test. The bioconductor package "iterativeBMAsurv" was applied with R statistical software for classification and survival analysis. Results: In this study, 25 genes associated with survival for MCL patients were identified across 132 selected models. The maximum likelihood estimate coefficients of the selected genes and the posterior probabilities of the selected models were obtained from training data. Using this method, patients could be separated into high-risk and low-risk groups with high significance (p<0.001). Conclusions: The iterative BMA algorithm has high precision and ability for survival analysis. This method is capable of identifying a few predictive variables associated with survival, among many variables in a set of microarray data. Therefore, it can be used as a low-cost diagnostic tool in clinical research.

• Journal of the Korea Computer Industry Society
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• v.2 no.9
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• pp.1191-1198
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• 2001

An increasingly important facet of software development is the ability to estimate the associate cost and effort of development early in the development life cycle. Most of the proposed models are based upon a combination of intuition, expert judgement, and regression analysis of empirical data. Overall, the work has failed to produce any single model that can be applied with a reasonable degree of success to a variety of environments. This paper presents a neural network (NN) model that related software development effort to software size measured in function element types. The heuristic approach is applied to decide the number of hidden neurons in NN from the relationship between input-output pairs. The research describes appropriate NN modeling in the context of a case study for 24 software development projects. Also, this paper compared the NN model with a regression analysis model and found the NN model has better accuracy.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.2
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• pp.357-363
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• 1992

The experiment was carried out to estimate the energy and protein requirements of Khaki Campbell $\times$ Thai Native growing ducks. The growing stage was divided into 2: the first was a starting stage from 0 to 4 weeks of age and the second was a growing stage from 4 to 18 weeks of age. In the starting stage, the birds were given diets containing 2.70, 2.75, 2.80, 2.85 and 2.90 Mcal ME/kg and ME/protein ratio of 150/l for the energy requirement trial, and diets containing 17.0%, 18.5%, 20.0% and 21.5% protein and 2.8 Mcal ME/kg for the protein requirement trial. It was found that there were no significant differences in body weight gain of feed efficiency among the energy or protein levels. In the growing stage, no significant differences in body weight gain or feed efficiency were found among the energy levels from 2.70 to 2.90 Mcal ME, or protein levels from 15.5% to 20.0%. The age at first lay was 105-117 days and this is earlier than that observed in purebred Khaki Campbell ducks. The feed cost for raising ducks was lower in the low energy and low protein diets. In conclusion, Khaki Campbell $\times$ Thai native ducks can be raised with a diet low in ME as 2.7 Mcal/kg during the whole growing period. As for the protein. 7.0% in the starting stage and 15.5% in the growing stage is practical.

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

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.311-318
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• 2004

Generally, PM BLDC drive system is necessary that the three Hall-ICs evenly be distributed around the stator circumference and encoder installed in case of the 3 phase motor. The Hall-ICs are set up in this motor to detect the main flux from the rotor. So the output signal from Hall-ICs is used to drive a power transistor to control the stator winding current. Instead of using three Hall-ICs and encoder, this paper uses only two Hall-ICs for the permanent magnet rotor position and for the speed feedback signals, and uses a micro controller of 16-bit type(80C196KC) with the 3 phase PM BLDC whose six stator and two rotor designed. Two Hall-IC Hc and $H_B$ are placed on the endplate at 120 degree phase difference. With these elements, we estimate information of the other phase in sequence through a rotating rotor.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.295-300
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• 2006

In this research, risk factors which can raise project cost are identified in the initial stage and picked out through the decision maker's baseline. And also this probable risks are implemented to the project cash flow to estimate the contingency and to build a risk management system in the level of project. The risks that affect the projects profits were classified in two categories in the risk checklist. Firstly, financial risks derived from the external economic conditions for example exchange rate, escalation, interest rates etc. are analyzed through the stochastic methods, Monte-Carlo Simulation. Secondly, the project individual risks which are come from the project characteristics, for example country risk, clime, owner etc., are evaluated using the utility curve of the decision maker. Finally these risk analysis methods are used to forecast the actual project cash flow and final profit.

• The KIPS Transactions:PartD
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• v.13D no.2 s.105
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• pp.241-250
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• 2006

Software maintenance is an important and very expensive activity in software life cycle. To estimate the maintainability cost of software, many software metrics have been proposed. This paper presents the result of an experimental study to explore the relationship between maintainability and some software metrics. LCOM, RFC, DAC, and LOC are employed as metrics and time really spent for maintenance activity has been collected. In the experimental study, we have found that for some systems, the existing metrics may not be an indicator to maintenance effort, which is not consistent with our general knowledge on the relationship between them. Specifically speaking, we recognized that there should be more empirical study on the relationship between metrics and maintainability of softwares which have been developed using recent technologies such as software architecture and design pattern.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.6A
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• pp.676-684
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• 2008

In digital video broadcasting-terrestrial (DVB-T), which is the European digital terrestrial television standard, the orthogonal frequency division multiplexing (OFDM) has been adopted for signal transmission. The main reasons using OFDM are to increase the robustness against the frequency selective fading and impulse noise, and to use available bandwidth efficiently. However, channel variation within an OFDM symbol destroys orthogonality between subcarriers, resulting in inter-carrier interference (ICI), which increases an error floor in proportional to maximum Doppler spread. This paper provides an ICI analysis in both time and frequency domains while existing literatures analyze the ICI effects mainly in frequency domain and proposes the algorithms that estimate the channel impulse response and channel variation using least square (LS) algorithm which is the most simple channel estimation technique. And we propose adaptive channel estimation algorithm that estimates the velocity of terminals. The simulation results show that proposed algorithm has similar performance with about 1.5% computational complexity of noise and ICI reduction LS algorithm in low speed environments.

• Journal of Korean Society of Rural Planning
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• v.24 no.2
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• pp.109-114
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• 2018

In this study, we estimate the greenhouse farmers' willingness to pay of agricultural water supply through pipeline. First, in the questionnaire design, orthogonal design and block design were used to enhance the ease of survey. Second, the theoretical model was constructed through the setting of the probability utility function, and the parameters were estimated by using the conditional logit model. Third, all of the estimation coefficients were statistically significant at the 1% significance level. The results of analysis are summarized as follows. First, the probability of selection is increased when maintenance is carried out by Korea Rural Community Corporation or local government. Second, the probability of selection is increased when agricultural water supply through pipeline is higher than the current level. Third, if the Korea Rural Community Corporation carries out maintenance management, the marginal willingness to pay is 44 won per ton. And if the local government carries out maintenance management, the marginal willingness to pay is 25 won per ton. Fourth, according to the quality level of agricultural water supply, the marginal willingness to pay is 101 won, 114 won and 120 won per ton, respectively. This study can be used as a basic data on the cost setting for agricultural water supply through pipeline.

• Journal of Korean Society of Steel Construction
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• v.14 no.5 s.60
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• pp.647-656
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• 2002

High-strength steel in steel bridges is the key to achieving cost-efficiency because it facilitates lightweight construction and rationalizes structure. The future of high-strength steel is bright, with its use projected to expand. As such, it is necessary to evaluate precisely various factors affecting the process of fabricating high-strength steel, i.e., welding heat, strain hardening, and weldability and performance of the welded joints. This study therefore performed the maximum hardness test and y-groove weld crack test using welding processes such as SAW, FCAW, and GMAW, in order to investigate the welding performance and characteristics of welded Joints or high-strength steel produced in Korea such as SM570, POSTEN60, and POSTEN80. In addition, a series of welding tests was carried out to estimate the tensile strength, bending characteristics, absorbed energy, and hardness in welded joints.