• 한국화재소방학회논문지
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• 제33권1호
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• pp.92-98
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• 2019

이 연구는 옥내소화전설비에 자동화점추적 기능을 부가하여 화재 발생위치에 따라 방수노즐이 이동하여 유효하게 방수하는지를 방수중심 지향여부, 방수범위 유지여부, 방수형태의 일관성 유지여부로 구분하여 실험하고 결과를 고찰하였다. 첫째, 방수중심 실험결과는 최초 화원의 중심을 찾는 정확도는 시스템 설계에 있어서 유효한 결과를 도출하게 됨을 확인하였다. 둘째, 방수범위 실험결과 방수최대반경의 물 분사를 하는 경우 방수범위의 오차는 허용공차 범위 내에 들어가는 것으로 확인되었다. 마지막으로 방수형태 실험결과 형태의 변화 없이 정상동작하여 설정블록에 대하여 설계상태가 이상 없음을 확인하였다.

• Geomechanics and Engineering
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• 제18권1호
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• pp.11-20
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• 2019

The purpose of this study was to propose a new approach for quantifying in situ rock mass damage, which would include a degree-of-damage and the degraded strength of a rock mass, along with its prediction based on real-time Acoustic Emission (AE) observations. The basic approach for quantifying in-situ rock mass damage is to derive the normalized value of measured AE energy with the maximum AE energy, called the degree-of-damage in this study. With regard to estimation of the AE energy, an AE crack source location algorithm of the Wigner-Ville Distribution combined with Biot's wave dispersion model, was applied for more reliable AE crack source localization in a rock mass. In situ AE wave attenuation was also taken into account for AE energy correction in accordance with the propagation distance of an AE wave. To infer the maximum AE energy, fractal theory was used for scale-independent AE energy estimation. In addition, the Weibull model was also applied to determine statistically the AE crack size under a jointed rock mass. Subsequently, the proposed methodology was calibrated using an in situ test carried out in the Underground Research Tunnel at the Korea Atomic Energy Research Institute. This was done under a condition of controlled incremental cyclic loading, which had been performed as part of a preceding study. It was found that the inferred degree-of-damage agreed quite well with the results from the in situ test. The methodology proposed in this study can be regarded as a reasonable approach for quantifying rock mass damage.

• 대한건축학회논문집:구조계
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• 제35권11호
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• pp.155-162
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• 2019

The construction industry is the highest safety accident causing industry as 28.55% portion of all industries' accidents in Korea. In particular, falling is the highest accidents type composed of 60.16% among the construction field accidents. Therefore, we analyzed the factors of major disaster affecting the fall accident and then derived feature importances by considering various variables. We used data collected from Korea Occupational Safety & Health Agency (KOSHA) for learning and predicting in the proposed model. We have an effort to predict the degree of occupational fall accidents by using the machine learning model, i.e., Adaboost, short for Adaptive Boosting. Adaboost is a machine learning meta-algorithm which can be used in conjunction with many other types of learning algorithms to improve performance. Decision trees were combined with AdaBoost in this model to predict and classify the degree of occupational fall accidents. HyOperpt was also used to optimize hyperparameters and to combine k-fold cross validation by hierarchy. We extracted and analyzed feature importances and affecting fall disaster by permutation technique. In this study, we verified the degree of fall accidents with predictive accuracy. The machine learning model was also confirmed to be applicable to the safety accident analysis in construction site. In the future, if the safety accident data is accumulated automatically in the network system using IoT(Internet of things) technology in real time in the construction site, it will be possible to analyze the factors and types of accidents according to the site conditions from the real time data.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권6호
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• pp.2049-2068
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• 2021

AI combined with NLP techniques has promoted the use of Virtual Assistants and have made people rely on them for many diverse uses. Conversational Agents are the most promising technique that assists computer users through their operation. An important challenge in developing Conversational Agents globally is transferring the groundbreaking expertise obtained in English to other languages. AI is making it possible to transfer this learning. There is a dire need to develop systems that understand secular languages. One such difficult language is Hindi, which is the fourth most spoken language in the world. Semantic similarity is an important part of Natural Language Processing, which involves applications such as ontology learning and information extraction, for developing conversational agents. Most of the research is concentrated on English and other European languages. This paper presents a Corpus-based word semantic similarity measure for Hindi. An experiment involving the translation of the English benchmark dataset to Hindi is performed, investigating the incorporation of the corpus, with human and machine similarity ratings. A significant correlation to the human intuition and the algorithm ratings has been calculated for analyzing the accuracy of the proposed similarity measures. The method can be adapted in various applications of word semantic similarity or module for any other language.

• Journal of Information Processing Systems
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• 제16권6호
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• pp.1424-1436
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• 2020

Although huge progress has been made in current image segmentation work, there are still no efficient segmentation strategies for tree image which is taken from natural environment and contains complex background. To improve those problems, we propose a method for tree image segmentation combining adaptive mean shifting with image abstraction. Our approach perform better than others because it focuses mainly on the background of image and characteristics of the tree itself. First, we abstract the original tree image using bilateral filtering and image pyramid from multiple perspectives, which can reduce the influence of the background and tree canopy gaps on clustering. Spatial location and gray scale features are obtained by step detection and the insertion rule method, respectively. Bandwidths calculated by spatial location and gray scale features are then used to determine the size of the Gaussian kernel function and in the mean shift clustering. Furthermore, the flood fill method is employed to fill the results of clustering and highlight the region of interest. To prove the effectiveness of tree image abstractions on image clustering, we compared different abstraction levels and achieved the optimal clustering results. For our algorithm, the average segmentation accuracy (SA), over-segmentation rate (OR), and under-segmentation rate (UR) of the crown are 91.21%, 3.54%, and 9.85%, respectively. The average values of the trunk are 92.78%, 8.16%, and 7.93%, respectively. Comparing the results of our method experimentally with other popular tree image segmentation methods, our segmentation method get rid of human interaction and shows higher SA. Meanwhile, this work shows a promising application prospect on visual reconstruction and factors measurement of tree.

• 한국정보통신학회논문지
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• 제26권1호
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• pp.30-40
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• 2022

심전도 신호는 개인에 따라 형태와 특징이 다양하므로, 하나의 신경망으로는 분류하기가 어렵다. 주어진 데이터를 직접적으로 분류하는 것은 어려우나, 대응되는 정상 데이터가 있을 경우, 이를 비교하여 정상 및 비정상을 분류하는 것은 상대적으로 쉽고 정확하다. 본 논문에서는 템플릿 군을 이용하여 대표정상심박 정보를 획득하고, 이를 입력 심박에 결합함으로써 심박을 분류한다. 결합된 심박을 영상화한 후, 학습 및 분류를 진행하여, 하나의 신경망으로도 다양한 레코드의 비정상심박을 검출이 가능하였다. 특히, GoogLeNet, ResNet, DarkNet 등 다양한 신경망에 대해서도 비교학습 기법을 적용한 결과, 모두 우수한 검출성능을 가졌으며, GoogLeNet의 경우 99.72%의 민감도로, 실험에 사용된 신경망 중 가장 우수한 성능을 가졌음을 확인하였다.

• 한국인터넷방송통신학회논문지
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• 제22권2호
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• pp.51-62
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• 2022

본 논문에서는 환자의 자세를 기반으로 행동을 예측하여, 의료진에 의해 입력된 개인의 병력 중심의 프로파일과 신체정보, 침상의 기본 정보를 모두 조합하여 침대에서의 낙상 위험을 예측하는 모델을 설계하고, 위험의 수준을 판단할 수 있는 알고리즘을 제시한다. 낙상 위험 예측은 크게 환자의 프로파일을 활용한 정성적 낙상 위험 노출도 평가와 실시간 낙상 위험 측정 단계로 구분된다. 정성적 낙상 위험 노출도는 의료진이 낙상 위험과 관련된 환자의 건강 상태를 점검하여 위험 노출도를 평가함으로써 위험 등급이 결정된다. 실시간 낙상 위험 측정 단계에서는 환자의 침대에서의 자세를 인식하고 환자의 정성적 위험등급 정보가 고려된 낙상 위험 측정을 위한 규칙 기반 정보를 추출한다. 인식된 환자 자세 정보와 정성적 위험평가 정보를 모두 조합하여 시그모이드 함수를 활용하여 최종 낙상 위험 수준을 예측한다. 본 연구에서 제시된 절차와 예측 모델은 입원 환자를 위한 낙상 사고 예방과 환자 안전을 위한 개인화 서비스에 크게 기여할 것으로 기대된다.

• Archives of Plastic Surgery
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• 제49권5호
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• pp.614-616
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• 2022

As of November 2021, TikTok has one billion monthly active users and is recognized as the most engaging social media platform. TikTok has seen a surge in users and content creators, ranging from athletes to medical professionals. In the past year, content creators have utilized the app to advocate for social reforms, education, and other uses that were not previously considered. Breast cancer is the most commonly diagnosed cancer in women, with an expected 281,550 new cases of invasive breast cancer in 2021. As more individuals with breast cancer choose to undergo resection, the demand for autologous fat grafting in breast reconstruction has increased due to the natural look and feel of breast tissue. The purpose of this article is to analyze content related to breast reconstruction with fat grafting found on TikTok and recommend methods to improve patient education, care, and outcomes. We searched TikTok on November 1, 2021, for videos using the phrase "breast reconstruction with fat grafting." The top 200 videos retrieved from the TikTok search algorithm were analyzed, and all commentaries, duplicates, and nonrelevant videos were removed. Video characteristics were collected, and two independent reviewers generated a DISCERN score A total of 131 videos were included in the study. They were found to have a combined 1,871,980 likes, 41,113 comments, and 58,662 shares. The videos had an average DISCERN score of 2.16. Content creators had an overall low DISCERN score in items involving the use of references, disclosure of risks for not obtaining treatment, and support for shared decision-making. When stratified, the DISCERN score was higher for videos created by physicians (DISCERN average 2.48) than for videos created by nonphysicians (DISCERN average 1.99; p < 0.001).

• 정보보호학회논문지
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• 제32권5호
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• pp.955-963
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• 2022

사물인터넷(Internet of Things, IoT)은 다양한 기술과 결합하여 일상생활의 전반으로 빠르게 자리 잡았다. 빠른 속도로 사회 전반에 자리 잡은 데 반해 보안에 대한 고려는 상대적으로 미흡하여 사이버 공격의 주요 대상이 되고 있다. IoT 환경의 모든 기기는 인터넷에 연결되어 일상생활과 밀접하게 활용되고 있기에 사이버 공격으로 인한 피해도 심각하다. 따라서 보다 안전한 IoT 환경에서의 서비스를 위해 네트워크 보안 프로토콜을 이용한 암호화 통신이 반드시 고려되어야 한다. 대표적인 네트워크 보안 프로토콜에는 IETF에서 정의한 TLS(Transport Layer Protocol)가 있다. 본 논문은 제한된 자원 특성을 갖는 IoT 기기에서 대표적인 네트워크 보안 프로토콜인 TLS의 부하를 예측하기 위하여 IoT 기기 오픈 플랫폼 환경에서 TLS 버전 1.2와 버전 1.3에 대한 성능 측정 결과를 분석한다. 또한 버전 1.3에서 지원하는 주요 암호화 알고리즘의 성능을 분석하여 IoT 기기 사양에 따라 적합한 네트워크 보안 프로토콜 속성을 설정할 수 있는 기준을 제시하고자 한다.

• Mass Spectrometry Letters
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• 제13권1호
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• pp.11-19
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• 2022

Although translational research is referred to clinical chemistry measures, correct weighting factors for linear and quadratic calibration curves with least-squares regression algorithm have not been carefully considered in bioanalytical assays yet. The objective of this study was to identify steroidogenic roles in preeclampsia and verify accuracy of quantitative results by comparing two different linear regression models with weighting factor of 1 and 1/x². A liquid chromatography-mass spectrometry (LC-MS)-based adrenal steroid assay was conducted to reveal metabolic signatures of preeclampsia in both serum and placenta samples obtained 15 preeclamptic patients and 17 age-matched control pregnant women (33.9 ± 4.2 vs. 32.8 ± 5.6 yr, respectively) at 34~36 gestational weeks. Percent biases in the unweighted model (w_i = 1) were inversely proportional to concentrations (-739.4 ~ 852.9%) while those of weighted regression (w_i = 1/x²) were < 18% for all variables. The optimized LC-MS combined with the weighted linear regression resulted in significantly increased maternal serum levels of pregnenolone, 21-deoxycortisol, and tetrahydrocortisone (P < 0.05 for all) in preeclampsia. Serum metabolic ratio of (tetrahydrocortisol + allo-tetrahydrocortisol) / tetrahydrocortisone indicating 11β-hydroxysteroid dehydrogenase type 2 was decreased (P < 0.005) in patients. In placenta, local concentrations of androstenedione were changed while its metabolic ratio to 17α-hydroxyprogesterone responsible for 17,20-lyase activity was significantly decreased in patients (P = 0.002). The current bioanalytical LC-MS assay with corrected weighting factor of 1/x² may provide reliable and accurate quantitative outcomes, suggesting altered steroidogenesis in preeclampsia patients at late gestational weeks in the third trimester.