• Structural Engineering and Mechanics
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• v.51 no.6
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• pp.989-1003
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• 2014

In the preliminary design stage of an RC 3D-frame, repeated sequential analyses to determine optimal members' sizes and the investigation of the parameters required to minimize the differential column shortening are computational effort consuming, especially when considering various types of loads such as dead load, temperature action, time dependent effects, construction and live loads. Because the desired accuracy at this stage does not justify such luxury, two backpropagation feedforward artificial neural networks have been proposed in order to approximate this information. Instead of using a commercial software package, many references providing advanced principles have been considered to code a program and generate these neural networks. The first one predicts the typical amount of time between two phases, needed to achieve the minimum maximorum differential column shortening. The other network aims to prognosticate sequential analysis results from those of the simultaneous analysis. After the training stages, testing procedures have been carried out in order to ensure the generalization ability of these respective systems. Numerical cases are studied in order to find out how good these ANN match with the sequential finite element analysis. Comparison reveals an acceptable fit, enabling these systems to be safely used in the preliminary design stage.

• Communications for Statistical Applications and Methods
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• v.15 no.5
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• pp.675-685
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• 2008

This paper studies two sequential procedures to estimate a monotone convex function using $L_2$ monotonization and uniform convexification; one, denoted by FMSC, monotonizes the data first and then, convexifis the monotone estimate; the other, denoted by FCSM, first convexifies the data and then monotonizes the convex estimate. We show that two shape modifiers are not commutable and so does FMSC and FCSM. We compare them numerically in uniform error(UE) and integrated mean squared error(IMSE). The results show that FMSC has smaller uniform error(UE) and integrated mean squared error(IMSE) than those of FCSC.

• Communications for Statistical Applications and Methods
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• v.5 no.2
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• pp.459-475
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• 1998

In many clinical trials, we are interested in comparing the failure time distribution of different treatment groups. Because of ethical and economic reasons, clinical trials need to be monitored for early dramatic benefits or potential harmful effects. Prior knowledge, evolving knowledge, statistical considerations, medical judgment and ethical principles are all involved in the decision to terminate a trial early, and thus the monitoring is usually carried out by an independent scientific committee. This paper reviews the recently proposed group sequential testing procedures for clinical trials with survival data. Design considerations of such clinical trials are also discussed. This paper compares the characteristics of each of these methods and provides the biostatisticians with the guidelines for choosing the appropriate group sequential methods in a given situation.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.1053-1066
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• 2005

In this paper we consider the problem of identifying and testing outliers in linear regression. First we consider the use of the so-called scale ratio tests for testing the null hypothesis of no outliers. This test is based on the ratio of two residual scale estimates. We show the asymptotic distribution of the test statistics and investigate its properties. Next we consider the problem of identifying the outliers. A forward sequential procedure using the suggested test is proposed. The new method is compared with classical procedure in the real data example. Unlike other forward procedures, the present one is unaffected by masking and swamping effects because the test statistic is based on robust scale estimate.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.05a
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• pp.15-19
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• 2008

The use of Precast Concrete (PC) stairways is increasing to replace existing Reinforced Concrete (RC) stairways for the faster construction and the better quality control. Among several already developed PC stairway construction methods, RC Core Sequential Construction Method by Using PC Stairways (COSEC) has advantages of 1) allowing core of a building to be built prior to PC stairways so that two different procedures will not interfere with each other, and 2) having a newly developed joint connection with the core so that the RC core and PC stairways can be easily put together. In this paper, cases of several construction sites with the PC stairways method are analyzed. The elements of the developed method are described for further application and improvement.

• 대한예방의학회:학술대회논문집
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• 1994.02b
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• pp.270-284
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• 1994

Interim analyses of randomized trials enable investigators to make more efficient use of limited research resources and to satisfy ethical requirements that a regimen be discontinued as soon as it has been established to have an inferior efficacy/toxicity profile. Unfortunately. the integrity and credibility of these trials can be compromised if inappropriate procedures are used in monitoring interim data. 'In this paper we discuss how group sequential designs provide useful guidelines that enable one to satisfy the valid objectives of interim monitoring while avoiding undesirable consequences, and we consider how flexible one can be in the way such designs are implemented. We also provide motivation for the role of data-monitoring committees in preserving study integrity and credibility in either government- or industry-sponsored trials. In our view. these committees should have multidisciplinary representation and membership limited to individuals free of apparent significant conflict of interest, and ideally should be the only individuals to whom the data analysis center provides interim results on relative efficacy of treatment regimens. Finally. we discuss some important practical issues such as estimation following group sequential testing, anal ysis of secondary outcomes after using a group sequential design applied to a primary outcome, early stopping of negative trials. and the role of administrative analyses.

• Proceedings of the IEEK Conference
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• 1998.10a
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• pp.417-420
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• 1998

A heuristic sweeping algorithm for an autonomous smearing robot which executes the area filling task is proposed. This algorithm searches tracking points with the obstacle andenvironment wall while the robot tracking whole workspace, and finds sequential tracking line by sequentally connecting the tracking points in such a way that (1) the line should be never crossed, (2) the total tracking points should be is linked as short as possible, and (3) the tracking link should be cross over the obstacle in the work-space. If the line pass through the obstacle, hierarchical collision free algorithm proposed is implied. The proposed algorithm consists of (1) collision detection procedure, (2) obstacle map making procedures, (3) tracking points generation procedures for subgosls, (4) tracking points scanning procedures, and (5) obstacle avoidance procedure.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.449-454
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• 2019

Background Most patients with head and neck cancer successfully undergo oncologic resection followed by free or local flap reconstruction, depending on the tumor's size and location. Despite effective curative resection and reconstruction, head and neck cancer patients still face a high risk of recurrence and the possibility of a second primary cancer. Moreover, surgeons hesitate to perform sequential reconstruction following curative resection for several reasons. Few large-scale studies on this subject are available. Therefore, we retrospectively evaluated the outcome of sequential head and neck reconstruction to determine the possible risks. Methods In total, 467 patients underwent head and neck reconstruction following cancer resection at our center from 2008 to 2017. Of these cases, we retrospectively reviewed the demographic and clinical features of 58 who had sequential head and neck reconstruction following resection of recurrent cancer. Results Our study included 43 males (74.1%) and 15 females (25.9%). The mean age at the initial operation was $55.4{\pm}15.3years$, while the mean age at the most recent operation was $59.0{\pm}14.3years$. The interval between the first and second operations was $49.2{\pm}62.4months$. Twelve patients (20.7%) underwent surgery on the tongue, and 12 (20.7%) had procedures on the oropharynx. Thirty-four patients (58.6%) received a sequential free flap reconstruction, and 24 patients (41.4%) were treated using locoregional flaps. No cases of flap failure occurred. Conclusions Our findings suggest that patients who need additional operations with recurrent head and neck cancer could optimally benefit from sequential curative resections and reconstructions.

• The KIPS Transactions:PartB
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• v.11B no.3
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• pp.353-360
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• 2004

The study on scene change detection in the compressed MPEG videos has been done by various approaches. However, most of these approacher accomplished scene change detection by carrying out decoding processes and then by comparing pixels with pixels. This approach it not suitable for real time applications owing to much computing time of decoding processes. Recently, the study on scene change detection algorithms using only information of compressed domain is becoming Increasingly important. In this paper, we propose a sequential access method as an efficient scene change detection algorithm in the compressed domain. According to the type of pictures in the compressed MPEG video streams (divided in I-blocks and each I-block into P-blocks), the proposed algorithm provides effective scene change detection by applying sequential access and block by block mechanism. The proposed sequential access method provides fast and accurate detection operation by reducing checking procedures of unnecessary pictures due to molt of operations in compressed domain and checking by block units. Also, this approach uses optimal algorithm to provide fast and accurate detection operation.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.2
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• pp.135-140
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• 2016

Corrective controllers enable fault diagnosis and tolerance for various faults in asynchronous sequential circuits without resort to redesign. In this paper, we propose a static corrective controller in order to decrease the size of the controller. Compared with dynamic controllers, static controllers can be made using only combinational circuits, as they need no inner states. We address the existence condition and design procedures for static corrective controllers that overcome state transition faults. To show the validity and advantage, the proposed controller is applied to an SEU error counter implemented on FPGA.