• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.29 no.1
• /
• pp.55-62
• /
• 2007

Radical paring of the cleft edge during primary cleft lip operation or repeated secondary surgeries can result in tightness of the upper lip. In case, the degree of the resulting side-to-side tension is very severe, the possibility of a lip switch flap must be considered. When the lip tightness accompanies a loss of more than two-thirds of the Cupid's bow, an Abbe flap is an alternative. The disadvantages of Abbe flap are scar formation on the lower lip, design of incision line on the upper lip, disharmony of colors, and the dysfunction of the orbicularis muscle. These problems have been recognized in the literature and extreme discretion has been advised in its application. We experienced four cases of Abbe flap operation which were designed differently to correct the secondary unilateral or bilateral cleft-lip nasal deformities. The Abbe flap operations resulted in removal of the scars and tightness of the upper lip, reconstruction of the Cupid's bow, lengthening of the columella, and therefore secondary cleft-lip nasal deformity could be corrected. It is thought that carefully applied Abbe flap is an appropriate method to relieve horizontal tightness or flattening of the upper lip which occured after primary operation of cleft lip.

• Journal of the Korean Dietetic Association
• /
• v.3 no.2
• /
• pp.123-140
• /
• 1997

The purpose of this study were to assess main management components that can lead to successful university foodservice operations. Specifically, it was intended to develop the tool which assesses the service quality, management, to assess the difference between customer importance from and perceptions of service quality, to compare management perceptions of customer importances with actual service delivery, and to identify internal problems which affect service quality with the use of gap model. Three types of questionnaires were developed and implemented for customers, foodservice personals and foodservice manager. Assessment tools were developed based on the literature review, SERVQUAL, GAP model, and the pilot study. Through the validity and reliability test, the questionnaires were revised. Questionnaires were distributed to 900 university students, 207 foodservice personnels, and 54 foodservice manager respectively. 831 university students, 177 foodservice personnels, and 48 foodservice manager were responded with a response rate of 92.3%, 85.5%, and 88.8% respectively. Statistical data analysis was completed using the SPSS programs for descriptive analysis, ANOVA. and SNK test. The results of this study can be summarized as follows : 1. In quality service management components, 31 quality service attributes were categorized and named into primary quality, secondary quality, hygiene, empathy, tangibles, reliability, responsiveness, and price by the factor analysis. 2. Importance mean score of customers was 4.02 out of 5, but perception mean score of customers was 2.55. So there was a relative big gap(1.47) between importance and perception scores, especially in three dimensions of responsiveness, primary quality, and hygiene. 3. It showed that customers' mean scores of perceived service quality by dimensions were the following order : price > reliability > secondary quality > hygiene > tangibles > primary quality > responsiveness > empathy. And the perception mean score of rented(2.59) or contracted(2.58) management was significantly higher than that of self-operated(2.48). 4. Customers' importances mean score which internal customers recognize was 4.23 out of 5, but service delivery mean score was 3.85. So there was a little gap(0.39) between management perceptions of customer importances and actual service delivery. 5. In gap model, SERVQUAL score showed -1.47, Gap 1 positive 0.15, gap 2 negative 0.61, and gap 3 was positive 0.19. 6. The internal problems were as follows : (1) The managers of University foodservice perceived well enough the customers' expectation value but their management competency was lacked in terms of responding customer needs, (2) The foodservice staff perceived service performance more highly than service quality specifications.

• Archives of Plastic Surgery
• /
• v.38 no.2
• /
• pp.161-165
• /
• 2011

Purpose: Zygomaticomaxillary complex (ZMC) fracture is one of the most common facial injuries after facial trauma. As ZMC composes major facial buttress, it is a key element of the facial contour. So, when we treat these fractures, the operator should have a concern with the symmetry to restore normal appearance and function. But sometimes, unfavorable results may occur. The aim of this study is to analyze the unsatisfied midfacial contour after ZMC fractures reduction retrospectively and to point out the notandum. Methods: 369 patients, treated for fractures of the ZMC were included in the study. After the operation, such as open reduction and internal fixation (ORIF with titanium or absorbable materials), open reduction, and closed reduction, midfacial contour was evaluated with plain films and 3-dimensional computed tomography. And unfavorable asymmetric midfacial contours were correcterd by secondary correction and re-evaluated. Gross photographs were obtained at outpatient clinic. Results: Total of 38 patients had got a facial asymmetry and among of them 24 patients were treated secondary revisional ORIF operations for correction of unfavorable result of after primary reduction. Two of them had received tertiary operations, three patients had got osteotomy more than after one year and six patients had got minor procedures. The etiology of asymmetry were lateral displaced simple fracture of arch (n=2), lateral displaced comminuted fracture of arch (n=6), comminuted arch fracture combined posterior root fracture (n=9), and communited arch and body fracture (n=12), severely contused soft tissue (n=9). After the manipulations outcomes were acceptable. Conclusion: To prevent the asymmetry in ZMC fracture reduction, complete analysis of fracture, choice of appropriate operation technique, consider soft tissue, and secure of zygoma position are important. Especially, we should be more careful about communited fracture of zygomatic body and lateral displacement, root fracture of zygomatic arch. Because they are commom causes that make facial asymmetry. To get optimal result, ensure the definite bony reduction.

• Journal of the Korean School Mathematics Society
• /
• v.16 no.1
• /
• pp.265-287
• /
• 2013

The purpose of this study was to analyze the trends of domestic research on teacher knowledge in mathematics in terms of its conceptualizations of teacher knowledge, topics, methods, subjects, and content domains. For this purpose, the papers published in 9 professional journals during the recent 14 years (1999-2012) were analyzed by 5 criteria. The results of this study showed that the concept of PCK was the most frequent, whereas its subcategories appeared in different forms. The most frequent research topic was survey of teacher knowledge. The qualitative research methodology was more frequently used than the quantitative methodology, whereas mixed one was hardly used. The subjects for research included a little more elementary school teachers than secondary counterparts, but did similarly both pre-service and in-service teachers. Whereas both the research on number and operations in elementary mathematics education and the research on function in secondary were active, the rest of content domains were not. On the basis of these results, this paper provides several implications for future research direction in teacher knowledge in mathematics.

• Restorative Dentistry and Endodontics
• /
• v.6 no.1
• /
• pp.109-114
• /
• 1980

Ease of manipulation, adequate mechanical properties, long years of experience and economical cost are the factors which have established amalgam as the most widely used material for dental restorations. But amalgam restoration may require replacement because of secondary caries, fracture, "fall-out", dimensional change, tarnish or corrosion etc.. These failures of amalgam restorations seem to arise from failures during operations rather than from the inherent shortcomings of the material itself or of the patient's mismanagement. It is anticipated that notonly number of analgam restoration, but failures will be increase after more extensive utilization of the medical insurance which began in 1977. Then authors think that it would be helpful for the development of better treatment in daily dental practice, to know the duration of amalgam restorations and the reasons for their replacement. The data for this survey was compiled from 2, 856 out-patients of the Department of Dentistry, Ewha Woman's University Hospital from January 1975 to December 1977. 260 cases among 1,718 fillings were studied, of which 205 cases both had a single reason for replacement and recognized the date of the previous filling. The results obtained were as follows; 1. Amalgam fillings were 58. 5 percent of all dental restorative materials. Of these, 15. 13 percent of the amalgam restorations had to be replaced. 2. The first reason for replacement of amalgam restorations was secondary caries (56.10%), the second was fracture (23.80%) and the third was "fall-out" (8.78%). 3. Among those amalgms requiring replacement, 52.2 percent had been in place less than 3 years, 70.7 percent within 5 years and 89.8 percent had been in place less than 10 years. Only 10.2 percent had been in place more than 10 years.

• KIPS Transactions on Computer and Communication Systems
• /
• v.4 no.12
• /
• pp.391-398
• /
• 2015

This paper devises a performance improvement and evaluation process of circuit minimization algorithms for mentorship education of distinguished informatics gifted secondary students. In the process, students learn that there are several alternative equivalent circuits for a target function and recognize the necessity for formalized circuit minimization methods. Firstly, they come at the concept of circuit minimization principle from Karnaugh Map which is a manual methodology. Secondly, they explore Quine-McCluskey algorithm which is a computational methodology. Quine-McCluskey algorithm's time complexity is high because it uses set operations. To improve the performance of Quine-McCluskey algorithm, we encourage them to adopt a bit-wise data structure instead of integer array for sets. They will eventually see that the performance achievement is about 36%. The ultimate goal of the process is to enlarge gifted students' interest and integrated knowledge about computer science encompassing electronic switches, logic gates, logic circuits, programming languages, data structures and algorithms.

• Explosives and Blasting
• /
• v.39 no.3
• /
• pp.24-34
• /
• 2021

Electronic detonators are widely used in various construction sites due to accurate delay time. Including the cases with exceeded noise and vibration from site using electric/non-electric detonator, electronic detonators are used to improve blast fragmentation or to reduce the cost of secondary partial blasting. Furthermore, the number of cases using electronic detonators are increased for reduction of the cost and construction period by maximizing operations efficiency. This case study is about applying electronic detonators on large section station, tunnel construction site which is the part of urban area GTX A project. Although it was initially planned to utilize non-electric detonators, damage was inflicted on safety-thing. We have considered blasting method using electronic detonators as solution of this problem. By applying electronic detonators, we not only satisfied environmental regulations but also prevented nearby safety-thing from getting damaged. In addition, we were able to shorten the construction period than the initial plan by conducting single simultaneous blasting on large section station, in order to ensure safe and efficient construction.

• Journal of IKEEE
• /
• v.25 no.4
• /
• pp.741-749
• /
• 2021

This paper presents the current-fed type LLC AC to DC high frequency resonant converter capable of ZVZCS(Zero-Voltage and Zero-Current Switching). The current-fed type LLC AC to DC high frequency resonant converter proposed in this paper could operate not only in ZVS(Zero-Voltage Switching) operation by connecting the resonant capacitors(C₁, C₂) in parallel across the switching devices but also in ZCS(Zero-Current Switching) operation of the secondary diode. The ZVS and ZCS operations can reduce the turn-on loss of the switching devices and the turn-off loss of the secondary diodes, respectively. The circuit analysis of current-fed type LLC AC to DC high frequency resonant converter proposed in this paper is addressed generally by adopting the normalized parameters. The operating characteristics of proposed LLC AC to DC high frequency resonant converter were also evaluated by using the normalized control parameters such as the normalized control frequency(μ), the normalized load resistor(λ) and so on. Based on the characteristic values through the characteristics of evaluation, an example of the design method of proposed LLC AC to DC high frequency resonant converter is suggested, and the validity of the theoretical analysis is confirmed using the experimental results and PSIM simulation.

• Journal of Computing Science and Engineering
• /
• v.8 no.4
• /
• pp.187-198
• /
• 2014

In this paper an efficient image encryption scheme based on cyclic rotations and multiple blockwise diffusions with two chaotic maps is proposed. A Sin map is used to generate round keys for the encryption/decryption process. A Pomeau-Manneville map is used to generate chaotic values for permutation, pixel value rotation and diffusion operations. The encryption scheme is composed of three stages: permutation, pixel value rotation and diffusion. The permutation stage performs four operations on the image: row shuffling, column shuffling, cyclic rotation of all the rows and cyclic rotation of all the columns. This stage reduces the correlation significantly among neighboring pixels. The second stage performs circular rotation of pixel values twice by scanning the image horizontally and vertically. The amount of rotation is based on $M{\times}N$ chaotic values. The last stage performs the diffusion four times by scanning the image in four different ways: block of $8{\times}8$ pixels, block of $16{\times}16$ pixels, principal diagonally, and secondary diagonally. Each of the above four diffusions performs the diffusion in two directions (forwards and backwards) with two previously diffused pixels and two chaotic values. This stage makes the scheme resistant to differential attacks. The security and performance of the proposed method is analyzed systematically by using the key space, entropy, statistical, differential and performance analysis. The experimental results confirm that the proposed method is computationally efficient with high security.

• Journal of Korea Spatial Information System Society
• /
• v.7 no.3 s.15
• /
• pp.55-65
• /
• 2005

This paper presents a bulk insertion technique for efficiently inserting data items. Traditional moving object database focused on efficient query processing that happens mainly after index building. Traditional index structures rarely considered disk I/O overhead for index rebuilding by inserting data items. This paper, to solve this problem, describes a new bulk insertion technique which efficiently induces the current positions of moving objects and reduces update cost greatly. This technique uses buffering technique for bulk insertion in spatial index structures such as R-tree. To analyze split or merge node, we add a secondary index for information management on leaf node of primary index. And operations are classified to reduce unnecessary insertion and deletion. This technique decides processing order of moving objects, which minimize split and merge cost as a result of update operations. Experimental results show that this technique reduces insertion cost as compared with existing insertion techniques.