• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.5
• /
• pp.619-633
• /
• 1993

A new High level hardware Description Language, ASPHODEL(Algorithm Synthesis Pascal Hardware for Optimal Design and Efficient Language), and its algorithm compiler for high level synthesis are described in this paper. The new HDL, appropriated to the description of algorithmic level and lower, models VLSI circuits as an abstracted block which is consisted of input/output ports and hierachical processors to control VLSI complexities with efficiency. Also, in order to improve the descriptive power, popular Pascal programming language is modified to build ASPHODEL syntax rules. ASPHODEL algorithm compiler generates an intermediate form through lexical and syntax analysis from ASPHODEL source codes. To show the validation of presented language and its compiler, those are applied to practical design examples.

• The Journal of Korean Association of Computer Education
• /
• v.14 no.6
• /
• pp.41-51
• /
• 2011

Informatics curriculum has been revised for informatics principles and concepts to effectively teach. According to the revised curriculum, researches are verifying the educational effects of algorithmic thinking and problem-solving abilities using programming language by applying it to various area. However, researches in programming education considering the level of student are yet incomplete. This research has analyzed the impact of the perceived level of problem solving on the performance of project completeness. As results of difference of project completeness, a high perceived level of problem solving group's performance of project completeness was higher than a low perceived level of problem solving group's one. Analysis of the impact of the perceived level of problem solving on the performance of project completeness, 'problem finding' factor had a significant impact. This research suggested the importance of 'problem finding' and self-reflecting introspective 'reviewing' stages in problem solving process using programming language.abstract of your study in English. This space is for the abstract of your study in English. This space is for the abstract of your study in English.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.38A no.11
• /
• pp.955-966
• /
• 2013

We propose two feedback interference cancellers(FICs) to improve the performance of the equalization digital on-channel repeater(EDOCR) with the FIC for the ATSC DTV broadcasting system. The FIC estimates the feedback channel between Tx. and Rx. antennas of the repeater by cross-correlating the reference signal and the feedback signal. Since there is a DC pilot which ruins the white property of the ATSC DTV signals, the FIC cannot estimate the feedback channel accurately. To solve the problem, the structural method which uses an additional DC pilot free reference for feedback channel estimation and the algorithmic method based on the digital signal processing which whitens the ATSC DTV signals and performs the feedback cancellation in the whitened signal domain. Simulation results show that the proposed two FICs show better feedback cancellation performance than the conventional FIC.

• Journal of the Korea Computer Industry Society
• /
• v.9 no.5
• /
• pp.197-206
• /
• 2008

Gifted education has drawn much attention in education in recent years and gifted education in computers in elementary education has been emerged as well throughout the country. Now computer algorithm education is considered as a core subject in the area because computer algorithm is the essence of computer technology on which information society relies technically, and also it provides theoretical basis for problem solving using computers. And we observe that fostering learner's creativity is crucial in learning computer algorithms because problem solving requires creativity in general. In the paper, we discuss the procedure to foster learner's creative problem solving ability which would greatly help students learn computer algorithms, and then we discuss how we can make algorithmic ideas into reality. Furthermore, we note that an appropriate level education is necessary for better results for outstanding students in the program, and lastly we propose ideas to improve current gifted elementary education in computers. The content of the paper is largely originated from experiences of teaching gifted elementary students conducted by a local university and sponsored by its municipal government for six years.

• Archives of Plastic Surgery
• /
• v.41 no.4
• /
• pp.379-386
• /
• 2014

Background Vulvar defects result chiefly from oncologic resection of vulvar tumors. Reconstruction of vulvar defects restores form and function for the purpose of coitus, micturition, and defecation. Many surgical options exist for vulvar reconstruction. The purpose of this article is to present our experience with vulvar reconstruction. Methods From 2007 to 2013, 43 women presented to us with vulvar defects for reconstruction. Their mean age at the time of reconstruction was 61.1 years. The most common cause of vulvar defect was from resection of vulvar carcinoma and extramammary Paget's disease of the vulva. Method s of reconstruction ranged from primary closure to skin grafting to the use of pedicled flaps. Results The main complications were that of long term hypertrophic and/or unaesthetic scarring of the donor site in 4 patients. Twenty-two patients (51%) were able to resume sexual intercourse. There were no complications of flap loss, wound dehiscence, and urethral stenosis. Conclusions We present a subunit algorithmic approach to vulvar reconstruction based on defect location within the vulva, dimension of the defect, and patient age and comorbidity. The gracilis and gluteal fold flaps are particularly versatile and aesthetically suited for reconstruction of a variety of vulvar defects. From an aesthetic viewpoint the gluteal fold flap was superior because of the well-concealed donor scar. We advocate the routine use of these 2 flaps for vulvar reconstruction.

• Archives of Plastic Surgery
• /
• v.41 no.4
• /
• pp.366-373
• /
• 2014

Background The advent of skin-sparing mastectomy has allowed for the reconstruction of the breast and nipple with improved cosmesis. However, the nipple-areolar complex (NAC) in Asian patients is more pigmented and scars easily. Therefore, commonly described incisions tend to result in poor aesthetic outcomes in Asian patients with breast cancer. Methods We describe an algorithmic approach to skin-sparing mastectomy incisions in Asian patients on the basis of the location of the biopsy scar and the tumor site and size. Four incision types are described: peri-areolar, a peri-areolar incision with a second distant skin paddle, "racquet handle," and peri-areolar with adjacent skin excision. Results 281 immediate breast reconstructions were performed between May 2001 and February 2012 after skin-sparing mastectomy. The mastectomy incisions used included the peri-areolar design (n=124, 44%), peri-areolar design with a second distant skin paddle (n=39, 14%), "racquet handle" (n=21, 7.5%), and peri-areolar design with adjacent skin excision (n=42, 14%). The traditional elliptical incision and other variants where the NAC outline was not preserved were performed in the remaining 55 patients. The average follow-up was 44.7 months during which there was 1 case of total flap loss and 7 cases of partial flap necrosis; all remaining flaps survived. 24% of the patients (68/281) underwent subsequent nipple reconstruction. Conclusions Our algorithm avoids breast incisions that are randomly placed or excessively long and prevents the unnecessary sacrifice of normal breast skin. This allows skin-sparing mastectomy and immediate breast reconstruction to be performed with a consistently achievable aesthetic result in Asian women without neglecting oncological safety.

• Journal of the Korean School Mathematics Society
• /
• v.16 no.4
• /
• pp.899-925
• /
• 2013

The purpose of this study was to examine how constructive-response questions in regular test was in aligned with the nature and goals of 2007 Curriculum Amendment. For this purpose, data were collected and analysed by using the framework for mathematical task and the cognitive demand of tasks suggested by Smith & Stein(1998) and mathematical proficiency suggested by National Research Council(2001). In particular, it aimed to reveal the overall picture of the level of cognitive demand and the proportion of mathematical proficiency of constructed-response items created by secondary mathematics teachers. The findings from the analysis showed that 70 percent of the constructed-response items were at low-level and the rest at high-level in terms of cognitive demand. Also, the constructed-response assessment focused on conputing (89%), understanding(45%), applying(30%) and least reasoning(17%). Most of the constructed-response items included computing and were algorithmic.

• School Mathematics
• /
• v.14 no.2
• /
• pp.213-232
• /
• 2012

The purpose of this study was to examine and analyze the cognitive demand of the mathematical tasks suggested in the middle school textbooks. In particular, it aimed to reveal the overall picture of the level of cognitive demand of the mathematical tasks on function in the textbooks. We adopted the framework for mathematical task analysis suggested by Stein & Smith (1998) and analyzed the mathematical tasks accordingly. The findings from the analysis showed that 95 percent of the mathematical tasks were at low level and the rest at high level in terms of cognitive demand. Most of the mathematical tasks in the textbooks were algorithmic and focused on producing correct answers by using procedures. In particular, the high level tasks were presented at the end of each chapter or unit for wrap up rather than as key resources.

• International Journal of Aeronautical and Space Sciences
• /
• v.11 no.1
• /
• pp.10-18
• /
• 2010

The purpose of this paper deals with direct multiple-shooting method (DMS) to resolve helicopter maneuver problems of helicopters. The maneuver problem is transformed into nonlinear problems and solved DMS technique. The DMS method is easy in handling constraints and it has large convergence radius compared to other strategies. When parameterized with piecewise constant controls, the problems become most effectively tractable because the search direction is easily estimated by solving the structured Karush-Kuhn-Tucker (KKT) system. However, generally the computation of function, gradients and Hessian matrices has considerably time-consuming for complex system such as helicopter. This study focused on the approximation of the KKT system using the matrix exponential and its integrals. The propose method is validated by solving optimal control problems for the linear system where the KKT system is exactly expressed with the matrix exponential and its integrals. The trajectory tracking problem of various maneuvers like bob up, sidestep near hovering flight speed and hurdle hop, slalom, transient turn, acceleration and deceleration are analyzed to investigate the effects of algorithmic details. The results show the matrix exponential approach to compute gradients and the Hessian matrix is most efficient among the implemented methods when combined with the mixed time integration method for the system dynamics. The analyses with the proposed method show good convergence and capability of tracking the prescribed trajectory. Therefore, it can be used to solve critical areas of helicopter flight dynamic problems.

• Journal of Educational Research in Mathematics
• /
• v.13 no.3
• /
• pp.247-265
• /
• 2003

The purpose of this study is to analyze the essence of ratio concept from educational viewpoint. For this purpose, it was tried to examine contents and organizations of the recent teaching of ratio concept in elementary school text of Korea from ‘Syllabus Period’ to ‘the 7th Curriculum Period’ In these text most ratio problems were numerically and algorithmically approached. So the Wiskobas programme was introduced, in which the focal point was not on mathematics as a closed system but on the activity, on the process of mathematization and the subject ‘ratio’ was assigned an important place. There are some educational implications of this study which needs to be mentioned. First, the programme for developing proportional reasoning should be introduced early Many students have a substantial amount of prior knowledge of proportional reasoning. Second, conventional symbol and algorithmic method should be introduced after students have had the opportunity to go through many experiences in intuitive and conceptual way. Third, context problems and real-life situations should be required both to constitute and to apply ratio concept. While working on contort problems the students can develop proportional reasoning and understanding. Fourth, In order to assist student's learning process of ratio concept, visual models have to recommend to use.