• Archives of Craniofacial Surgery
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• v.20 no.2
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• pp.76-83
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• 2019

Background: The mental V-Y advancement flap method is useful for reconstruction of lower lip defect because of its many advantages. However, it is not easy to select the optimal reconstructive method for the vermilion defect that remains after application of the mental V-Y advancement flap. In choosing the representative surgical method for vermilion mucosal reconstruction including mucosal V-Y advancement flap, buccal mucosal flap, and buccal mucosal graft. We describe an efficient technique to large lower lip defects combining mental V-Y advancement flap and buccal mucosal graft Methods: This study included 16 patients who underwent reconstructive surgery for full-thickness and large defect (> half the entire width) of the lower lip from October 2006 to September 2017. The operation was conducted using mental V-Y advancement flap with various vermilion mucosal reconstruction methods considering the location of the defect and the amount of residual tissue of the lip coloboma after excision. Results: All patients underwent mental V-Y advancement flap. In vermilion mucosal reconstruction, five patients underwent mucosal V-Y advancement flap, three underwent buccal mucosal flap, and eight underwent buccal mucosal graft. There were good aesthetic and functional results in all patients who underwent buccal mucosal graft. However, two patients who underwent mucosal V-Y advancement flap complained of oral incompetence, and all patients who underwent buccal mucosal flap had oral commissure deformity. Conclusion: Buccal mucosal graft combined with mental V-Y advancement flap can produce suitable functional and aesthetic outcomes in near total lower lip reconstruction in patient with large mucosal defect including vermilion portion.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.4
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• pp.605-610
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• 2021

Wireless charging method using a laser is considered as the most efficient method at a long distance of the wireless charging method. Combining long-range laser wireless charging technology with wireless communication technology will make it possible to use it for a variety of applications. Accordingly, this paper shows the results of research and experiments on wireless charging and wireless communication simultaneously based on a laser. This technique uses a laser as a light source for E/O(: Electric-to-Optical) conversion at the transmitter for optical wireless power transmission. In the experimental results, the optical power transmission using a 100 mW laser transmitter and a solar cells receiver showed a DC-to-DC efficiency of 1.9 %, wireless optical communication showed a transmission speed of up to 90 kbps when the transmission distance is 15 m.

• The Korean Journal of Applied Statistics
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• v.34 no.4
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• pp.599-609
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• 2021

Data with a large difference in the number of objects between clusters are called unbalanced data. In discriminant analysis of unbalanced data, it is more important to classify objects in minority categories than to classify objects in majority categories well. However, objects in minority categories are often misclassified into majority categories. In this study, we propose a method that combined hierarchical DBSCAN (HDBSCAN) and SMOTE to solve this problem. Using HDBSCAN, it removes noise in minority categories and majority categories. Then it applies SMOTE to create new data. Area under the roc curve (AUC) and F1 scores were used to compare performance with existing methods. As a result, in most cases, the method combining HDBSCAN and synthetic minority oversampling technique (SMOTE) showed a high performance index, and it was found to be an excellent method for classifying unbalanced data.

• Physical Therapy Korea
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• v.28 no.3
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• pp.161-167
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• 2021

Understanding sciences behind fall-related hip fractures in older adults is important to develop effective interventions for prevention. The aim of this review is to provide biomechanical understanding and prevention strategies of falls and related hip fractures in older adults, in order to guide future research directions from biomechanical perspectives. While most hip fractures are due to a fall, a few of falls are injurious causing hip fractures, and most falls are non-injurious. Fall mechanics are important in determining injurious versus non-injurious falls. Many different biomechanical factors contribute to the risk of hip fracture, and effects of each individual factors are known well. However, combining effects, and correlation and causation among the factors are poorly understood. While fall prevention interventions include exercise, vision correction, vitamin D intake and environment modification, injury prevention strategies include use of hip protectors, compliant flooring and safe landing strategies, vitamin D intake and exercise. While fall risk assessments have well been established, limited efforts have been made for injury risk assessments. Better understanding is necessary on the correlation and causation among factors affecting the risk of falls and related hip fractures in older adults. Development of the hip fracture risk assessment technique is required to establish more efficient intervention models for fall-related hip fractures in older adults.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.5
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• pp.576-583
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• 2020

This paper proposes a technique to determine the spam comments on YouTube, which have recently seen tremendous growth. On YouTube, the spammers appeared to promote their channels or videos in popular videos or leave comments unrelated to the video, as it is possible to monetize through advertising. YouTube is running and operating its own spam blocking system, but still has failed to block them properly and efficiently. Therefore, we examined related studies on YouTube spam comment screening and conducted classification experiments with six different machine learning techniques (Decision tree, Logistic regression, Bernoulli Naive Bayes, Random Forest, Support vector machine with linear kernel, Support vector machine with Gaussian kernel) and ensemble model combining these techniques in the comment data from popular music videos - Psy, Katy Perry, LMFAO, Eminem and Shakira.

• Journal of Information Technology Services
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• v.19 no.6
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• pp.145-159
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• 2020

Because of the recent development of information and communication technology, companies are exposed to various media such as blogs, social media, and YouTube. In particular, exposed news affects the company's reputation. So, while positive news can improve corporate value, negative news can lead to financial losses for the company. In this study, we redefine corporate reputation as social responsibility, vision and leadership, financial performance, products and services through existing literature, and conducted an AHP survey with a total of four components to calculate the weight of each factor. As a result of the calculation, the proportion of financial performance was the highest at 0.41, and products and services, vision and leadership, and social responsibility were the lowest. In addition, in order to measure the reputation of a company, it is classified as a component that defines online news using the LDA technique. In addition, through sentiment analysis, an index for each corporate reputation factor was derived, and the reputation index was calculated by combining it with the AHP analysis result, and Spearman ranking correlation analysis was performed to secure the validity of the research results. Therefore, the significance of this study is that the definition and importance of the constituent factors can contribute to the future planning and development direction of the company, and also contribute to the derivation of the corporate reputation index. This study is significant in that a new analysis methodology that applied AHP analysis results to sentiment analysis was suggested.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.15 no.2
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• pp.124-133
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• 2022

With the development of hardware technology and the advancement of numerical model methods, more precise weather forecasts can be carried out. In this paper, we propose a Unicon Optimization scheme combining Loop Vectorization, Dependency Vectorization, and Code Modernization to optimize and increase Maintainability the Unicon source contained in SCAM, a simplified version of CESM, and present an overall SCAM structure. This paper tested the unicorn optimization scheme in the SCAM structure, and compared to the existing source code, the loop vectorization resulted in a performance improvement of 3.086% and the dependency vectorization of 0.4572%. And in the case of Unicorn Optimization, which applied all of these, the performance improvement was 3.457% compared to the existing source code. This proves that the Unicorn Optimization technique proposed in this paper provides excellent performance.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.2
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• pp.96-108
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• 2022

In this paper, we propose a systematic hull form variation technique which automatically satisfies the displacement constraint and guarantees a high level of fairness. This method is possible through multiple parameter correction curves. The present method is to improve the hull form variation method based on parametric modification function and consists of two sub-categories: SAC variation and section lines modification. For SAC variation, the utilization of two B-Spline curves satisfying GC¹ condition led to the satisfaction of displacement constraint and high level of fairness at the same time. Section lines modification methods involves in using two fuctions: the first is the waterplane modification function combining two cubic splines. the other function is the sectional area modification function consisting of 2nd order polynomial over the DLWL(Design Load Waterline) and 3rd order polynomial below the DLWL, This function enables not only the fundamental U-V section shape variation but also systematically modified section lines. The present method is expected to be more useful in the hull form optimization process using CFD compared to the existing method.

• Journal of Advanced Navigation Technology
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• v.26 no.4
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• pp.185-194
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• 2022

Avionics equipment requires various environmental conditions and performance during development, and as a countermeasure against such development risk, the worst-case circuit analysis(WCCA) is applied to predict perform preliminary performance analysis. WCCA calculates the maximum and minimum values by combining the parameter values of the relevant circuit after deriving the parameter values in consideration of the aging of the temperature and operating period at the component level. In this paper, the necessary matters for WCCA application are described. Chapter 2 describes the differences and characteristics of the WCCA techniques EVA, RSS, and Monte Carlo.Chapter 3 introduces the analysis process through the example circuit to introduce the actual analysis procedure. Chapter 4 describes the method of selecting an analysis technique for each condition of the analysis target. As a result of applying the procedures and analysis methods introduced in this paper when open, it was confirmed that preliminary performance analysis and part optimization design verification are possible.

• Korean Journal of Remote Sensing
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• v.39 no.4
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• pp.409-423
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• 2023

North Korea is carrying out reclamation activities in tidal flat areas distributed throughout the west coast. Previousremote sensing research on North Korean tidal flats either failsto reflect recent trends or focuses on identifying and analyzing tidal flats. Thisstudy aimsto quantify the impact of recent reclamation activitiesin North Korea's coastal areas and contribute knowledge useful for determining the best remote sensing methods for coastal areas with limited accessibility, such as those in North Korea. Using Landsat-8 OLI images from 2014-2022, we analyzed land cover changesin an area on the west coast of Pyeonganbuk-do where reclamation activities are underway. Unsupervised classification using the normalized difference water index and the random forest classification technique were each used to divide the study area into classification groups, and changes in their areas over time were analyzed. The resultsshow a clear decrease in the water area and a tendency to increase cultivated area,supporting the evidence that North Korea'sreclamation isfor agricultural land expansion.Along coasts behind seawalls, the water area decreased by nearly half, and the cultivated area increased by over 2,300%, indicating significant changes and highlighting the anthropogenic nature of the cover changes due to reclamation. Both methods demonstrated high accuracy, making them suitable for detecting cover changes caused by reclamation. It is expected that further quality research will be conducted through the use of high-resolution satellite images and by combining data from multiple satellites in the future.