• Journal of Microbiology and Biotechnology
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• 제33권8호
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• pp.1101-1110
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• 2023

Streptococcus mutans is the primary causative agent of caries, which is one of the most common human diseases. Thus, rapid and early detection of cariogenic bacteria is critical for its prevention. This study investigated the combination of loop-mediated isothermal amplification (LAMP) and microfluid technology to quantitatively detect S. mutans. A low-cost, rapid microfluidic chip using LAMP technology was developed to amplify and detect bacteria at 2.2-2.2 × 10⁶ colony-forming units (CFU)/ml and its detection limits were compared to those of standard polymerase chain reaction. A visualization system was established to quantitatively determine the experimental results, and a functional relationship between the bacterial concentration and quantitative results was established. The detection limit of S. mutans using this microfluidic chip was 2.2 CFU/ml, which was lower than that of the standard approach. After quantification, the experimental results showed a good linear relationship with the concentration of S. mutans, thereby confirming the effectiveness and accuracy of the custom-made integrated LAMP microfluidic system for the detection of S. mutans. The microfluidic system described herein may represent a promising simple detection method for the specific and rapid testing of individuals at risk of caries.

• 한국정보통신학회논문지
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• 제22권9호
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• pp.1228-1236
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• 2018

최근 폐어구로 인한 해양 환경오염이 심각하게 대두되고 있으며, ICT 기술의 접목을 통해 어구를 체계적으로 관리함으로서 이러한 문제를 해결하기 위한 방법이 요구되고 있다. 기존 어구 식별 및 관리를 위한 시스템들은 소유주의 선택에 의해 사용하던 실정으로 보다 통합적이고 국가적인 관제 체계가 필요하다. 이를 위해 본 논문에서는 어구에 자동식별 부이를 부착하고, 사물인터넷망을 활용하여 어구의 위치 및 상태정보를 어선, 관리 선박, 육상 관제센터 등으로 전송하여 효과적인 모니터링 및 관리가 가능하도록 하는 체계를 소개하며, 특히 통합 관제 시스템의 개발 및 기능 성능 검증에 관한 내용을 중점적으로 다룬다. 개발하는 시스템은 효율적인 어구 관제를 위하여 전자해도를 기반으로 어구 위치, 상태정보, 유실알람 등을 표시해주는 기능을 한다. 또한, 가상 어구 자동식별 부이 생성 모듈을 개발하고, 이를 기반으로 개발한 시스템의 처리 및 시각화 성능을 테스트하는 것에 관한 내용을 다룬다.

• Geomechanics and Engineering
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• 제35권2호
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• pp.195-208
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• 2023

The nodular diaphragm wall (NDW) is a novel type of foundation with favorable engineering characteristics, which has already been utilized in high-rise buildings and high-speed railways. Compared to traditional diaphragm walls, the NDW offers significantly improved vertical bearing capacity due to the presence of nodular parts while reducing construction time and excavation work. Despite its potential, research on the vertical bearing characteristics of NDW requires further study, and the investigation and visualization of its displacement pattern and failure mode are scant. Meanwhile, the measurement of the force component acting on the nodular parts remains challenging. In this paper, the vertical bearing characteristics of NDW are studied in detail through the indoor model test, and the displacement and failure mode of the foundation is analyzed using particle image velocimetry (PIV) technology. The principles and methods for monitoring the force acting on the nodular parts are described in detail. The research results show that the nodular part plays an essential role in the bearing capacity of the NDW, and its maximum load-bearing ratio can reach 30.92%. The existence of the bottom nodular part contributes more to the bearing capacity of the foundation compared to the middle nodular part, and the use of both middle and bottom nodular parts increases the bearing capacity of the foundation by about 9~12% compared to a single nodular part of the NDW. The increase in the number of nodular parts cannot produce a simple superposition effect on the resistance born by the nodular parts since the nodular parts have an insignificant influence on the exertion and distribution of the skin friction of NDW. The existence of the nodular part changes the displacement field of the soil around NDW and increases the displacement influence range of the foundation to a certain extent. For NDWs with three different nodal arrangements, the failure modes of the foundations appear to be local shear failures. Overall, this study provides valuable insights into the performance and behavior of NDWs, which will aid in their effective utilization and further research in the field.

• Korean Journal of Radiology
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• 제25권4호
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• pp.384-394
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• 2024

Objective: To evaluate the image quality of novel dark-blood computed tomography angiography (CTA) imaging combined with deep learning reconstruction (DLR) compared to delayed-phase CTA images with hybrid iterative reconstruction (HIR), to visualize the cervical artery wall in patients with Takayasu arteritis (TAK). Materials and Methods: This prospective study continuously recruited 53 patients with TAK (mean age: 33.8 ± 10.2 years; 49 females) between January and July 2022 who underwent head-neck CTA scans. The arterial- and delayed-phase images were reconstructed using HIR and DLR. Subtracted images of the arterial-phase from the delayed-phase were then added to the original delayed-phase using a denoising filter to generate the final-dark-blood images. Qualitative image quality scores and quantitative parameters were obtained and compared among the three groups of images: Delayed-HIR, Dark-blood-HIR, and Dark-blood-DLR. Results: Compared to Delayed-HIR, Dark-blood-HIR images demonstrated higher qualitative scores in terms of vascular wall visualization and diagnostic confidence index (all P < 0.001). These qualitative scores further improved after applying DLR (Dark-blood-DLR compared to Dark-blood-HIR, all P < 0.001). Dark-blood DLR also showed higher scores for overall image noise than Dark-blood-HIR (P < 0.001). In the quantitative analysis, the contrast-to-noise ratio (CNR) values between the vessel wall and lumen for the bilateral common carotid arteries and brachiocephalic trunk were significantly higher on Dark-blood-HIR images than on Delayed-HIR images (all P < 0.05). The CNR values were significantly higher for Dark-blood-DLR than for Dark-blood-HIR in all cervical arteries (all P < 0.001). Conclusion: Compared with Delayed-HIR CTA, the dark-blood method combined with DLR improved CTA image quality and enhanced visualization of the cervical artery wall in patients with TAK.

• 한국정보통신학회논문지
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• 제25권2호
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• pp.193-201
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• 2021

용접은 선박 및 해양플랜트의 생산 및 건조에 있어 매우 높은 비중을 차지하는 작업이다. 용접부의 품질 검증을 위해 비파괴 검사를 수행하는데, 우리나라에서는 주로 방사선투과검사(RT)를 활용한다. 현재 대부분의 조선소에서는 용접부의 촬영을 통해 얻어진 필름을 인화하여 검사에 활용하는 아날로그 형태를 채택하고 있다. 이에 방사선 촬영에서부터 합부 판정까지 소요시간이 길고 복잡하며, 관련 분야의 자격을 보유한 검사자에 의해 수작업으로 진행되고 있는 실정이다. 본 논문에서는 이러한 문제를 개선하기 위해 조선소에서 발생하고 있는 RT 필름을 고해상도로 스캔하여 디지털화한 후, 관리 서버에 축적하고, 인공지능 기술을 적용하여 용접 결함을 판독하기 위한 플랫폼에 관한 내용을 다룬다. 이를 위한 일련의 요소인 아날로그 RT 필름 스캔장비, 용접 검사 정보 통합 관리 플랫폼, 결함 판독 알고리즘, 시각화 소프트웨어 등을 설계 및 개발하고, 개발한 각 요소를 상호 연계하여 테스트 및 검증하는 과정에 관하여 기술한다.

• 지능정보연구
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• 제20권4호
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• pp.89-105
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• 2014

Web2.0의 등장과 함께 급속히 발전해온 온라인 포럼, 블로그, 트위터, 페이스북과 같은 소셜 미디어 서비스는 소비자와 소비자간의 의사소통을 넘어 이제 기업과 소비자 사이의 새로운 커뮤니케이션 매체로도 인식되고 있다. 때문에 기업뿐만 아니라 수많은 기관, 조직 등에서도 소셜미디어를 활용하여 소비자와 적극적인 의사소통을 전개하고 있으며, 나아가 소셜 미디어 콘텐츠에 담겨있는 소비자 고객들의 의견, 관심, 불만, 평판 등을 분석하고 이해하며 비즈니스에 적용하기 위해 이를 적극 분석하는 단계로 진화하고 있다. 이러한 연구의 한 분야로서 비정형 텍스트 콘텐츠와 같은 빅 데이터에서 저자의 감성이나 의견 등을 추출하는 오피니언 마이닝과 감성분석 기법이 소셜미디어 콘텐츠 분석에도 활발히 이용되고 있으며, 이미 여러 연구에서 이를 위한 방법론, 테크닉, 툴 등을 제시하고 있다. 그러나 아직 대량의 소셜미디어 데이터를 수집하여 언어처리를 거치고 의미를 해석하여 비즈니스 인사이트를 도출하는 전반의 과정을 제시한 연구가 많지 않으며, 그 결과를 의사결정자들이 쉽게 이해할 수 있는 시각화 기법으로 풀어내는 것 또한 드문 실정이다. 그러므로 본 연구에서는 소셜미디어 콘텐츠의 오피니언 마이닝을 위한 실무적인 분석방법을 제시하고 이를 통해 기업의사결정을 지원할 수 있는 시각화된 결과물을 제시하고자 하였다. 이를 위해 한국 인스턴트 식품 1위 기업의 대표 상품인 N-라면을 사례 연구의 대상으로 실제 블로그 데이터와 뉴스를 수집/분석하고 결과를 도출하였다. 또한 이런 과정에서 프리웨어 오픈 소스 R을 이용함으로써 비용부담 없이 어떤 조직에서도 적용할 수 있는 레퍼런스를 구현하였다. 그러므로 저자들은 본 연구의 분석방법과 결과물들이 식품산업뿐만 아니라 타 산업에서도 바로 적용 가능한 실용적 가이드와 참조자료가 될 것으로 기대한다.

• Imaging Science in Dentistry
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• 제49권4호
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• pp.265-272
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• 2019

Purpose: To compare the diagnostic accuracy of cone-beam computed tomography (CBCT) with that of parallel(PPA) and oblique projected periapical(OPA) radiography for the detection of different types of peri-implant bone defects. Materials and Methods: Forty implants inserted into bovine rib blocks were used. Thirty had standardized bone defects(10 each of angular, fenestration, and dehiscence defects), and 10 were defect-free controls. CBCT, PPA, and OPA images of the samples were acquired. The images were evaluated twice by each of 2 blinded observers regarding the presence or absence and the type of the defects. The area under the receiver operating characteristic curve (AUC), sensitivity, and specificity were determined for each radiographic technique. The 3 modalities were compared using the Fisher exact and chi-square tests, with P<0.05 considered as statistical significance. Results: High inter-examiner reliability was observed for the 3 techniques. Angular defects were detected with high sensitivity and specificity by all 3 modalities. CBCT and OPA showed similar AUC and sensitivity in the detection of fenestration defects. In the identification of dehiscence defects, CBCT showed the highest sensitivity, followed by OPA and PPA, respectively. CBCT and OPA had a significantly greater ability than PPA to detect fenestration and dehiscence defects(P<0.05). Conclusion: The application of OPA radiography in addition to routine PPA imaging as a radiographic follow-up method for dental implantation greatly enhances the visualization of fenestration and dehiscence defects. CBCT properly depicted all defect types studied, but it involves a relatively high dose of radiation and cost.

• 한국수소및신에너지학회논문집
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• 제28권2호
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• pp.121-128
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• 2017

For an investigation on the effect of the shape of electrodes in alkaline water electrolysis, two kinds of stack with circular and square electrode array are used to visualize both for behaviors of hydrogen bubble around the electrodes and for measurements of hydrogen production from these two stacks. The electrolytes for the hydrogen production experiment were applied for 20 wt%, 25 wt%, 30 wt% and 35 wt% of KOH alkaline aqueous solutions. As a result, the adhesion length of bubbles attached around the square electrode in the visualization experiment was found to be 1.7 times longer compared with the attached around the circular electrode. In the hydrogen production experiments, the volume of hydrogen production of the stack by using circular electrode array was approximately 3% more than that of the stack with square electrode array. These observations may be caused by the effect of the bubbles attached to the around the electrodes obstructing mass transfer such as hydrogen exhaust and electrolyte supply.

• 대한수의학회지
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• 제50권4호
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• pp.311-317
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• 2010

Recently the micropig has been developed as human disease model. The dental and orofacial region of micropig is similar to that of humans, so it has been used for testing implant materials and techniques. The purpose of this study is on dental image at each age using radiography and computed tomography. Total twenty-two male micropigs, two or three animals of each 1, 3, 5, 7, 9, 12, 18 and 24 months old, were given radiographic examinations. After general anesthesia, extra- and intra-oral radiographic technique and computed tomographic scans were performed to assess the dental characterization of micropigs. The total deciduous dental formula comprised 28 teeth and was depicted as Di 3/3, Dc 1/1, Dp 3/3. The total permanent dental formula comprised 44 teeth and was depicted as I 3/3, C 1/1, P 4/4, M 3/3. Hypodontia of the first premolars was common in the micropig. The permanent teeth erupted from 3 to 24 month after birth. The sequence of eruption of the permanent teeth was M1, P1, I3, C, M2, I1 + P3 + P4, P2, I2, M3. Dental imaging enables visualization of the unerupted teeth and gives more information about the development of the teeth. The growth pattern of the teeth obtained through radiographic and computed tomographic examination provides basic data in the micropig as animal model for dental research.

• 대한족부족관절학회지
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• 제5권2호
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• pp.103-111
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• 2001

Purpose: The purpose of this study was to evaluate prognostic factors of ankle arthroscopy and the effectiveness of high anteromedial and anterolateral portals in diagnosis and treatment for various disease entities. Materials and Methods: The results of ankle arthroscopy were evaluated between March 1992 and January 2000 by one surgeon. Total 169 patients who were followed for a minimum of 12 months, were included in this study. Using high anteromedial and high anterolateral portals, all procedures were done with accessory portals if necessary. A functional evaluation was performed using the Karlsson score and questionnaire subjectively. Results: Fifty-six synovial impingement, 48 osteochondral lesion on talus, 10 impingement exostosis, 8 loose body, 27 osteoarthritis and chondromalacia, 10 postfracture fibrosis, 3 lateral plica, and 1 pigmented villonodular synivitis(PVNS) among 169 patients were diagnosed. Patients with the former four groups had satisfactory results and the latter four groups had not. Remaining 6 patients underwent arthroscopic arthrodesis, and 5 had satisfactory results. Conclusion: Using high anteromedial and anterolateral portals, we could get better visualization of talar dome and posterior chamber of ankle. For better clinical results, in ankle arthroscopy, not only operative skill but also proper indications are important. In case of synovial impingement after trauma, arthroscopy should be considered within one year after initial trauma. There were little correlation between the radiographic findings and arthroscopic findings of articular cartilage in osteochondral lesion of talus, and it is better to determine treatment modality based on the arthroscopic or MRI findings. Osteochondral lesions were treated successfully only when they were traumatically induced and localized without diffuse chondromalacia of talus and tibia.