• 제목/요약/키워드: forensic science

검색결과 454건 처리시간 0.031초

웨이브렛 계수를 이용한 고저항 지락고장 감시데이터 산출방법 연구 (A Study on the Developing Method of HIF Monitoring Data using Wavelet Coefficient)

  • 정영범;정연하;김길신;이병성;배승철
    • 전기학회논문지
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    • 제62권2호
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    • pp.155-163
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    • 2013
  • As the increasing HIF(High Impedance Fault) with the arc cannot be easily detected for the low fault current magnitude compared to actual load in distribution line. However, the arcing current shows that the magnitude varies with time and the signal is asymmetric. In addition, discontinuous changes occur at starting point of arc. Considering these characteristics, wavelet transformation of actual current data shows difference between before and after the fault. Althogh raw data(detail coefficient) of wavelet transform may not be directly applied to HIF detection logic in a device, there are several developing methods of HIF monitoring data using the original wavelet coefficients. In this paper, a simple and effective developing methods of HIF monitoring data were analized by using the signal data through an actual HIF experiment to apply them to economic devices. The methods using the sumation of the wavelet coefficient squares in one cycle of the fundamental frequency as the energies of the wavelet coefficeits and the sumation of the absolute values were compared. Besides, the improved method which less occupies H/W resouces and can be applied to field detection devices was proposed. and also Verification of this HIF detection method through field test on distribution system in KEPCO power testing center was performed.

Head and neck radiotherapy-induced changes in dentomaxillofacial structures detected on panoramic radiographs: A systematic review

  • Munhoz, Luciana;Nishimura, Danielle Ayumi;Iida, Christyan Hiroshi;Watanabe, Plauto Christopher Aranha;Arita, Emiko Saito
    • Imaging Science in Dentistry
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    • 제51권3호
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    • pp.223-235
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    • 2021
  • Purpose: This study aimed to summarize the impact of neck and head radiation treatment on maxillofacial structures detected on panoramic radiographs. Materials and Methods: In this systematic review, the authors searched PubMed Central, Embase, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar for original research studies up to February 2020 that included the following Medical Subject Headings keywords: words related to "radiotherapy" and synonyms combined with keywords related to "panoramic radiography" and "oral diagnosis" and synonyms. Only original studies in English that investigated the maxillofacial effects of radiotherapy via panoramic radiographs were included. The quality of the selected manuscripts was evaluated by assessing the risk of bias using Cochrane's ROBINS-I tool for non-randomized studies. Results: Thirty-three studies were eligible and included in this review. The main objectives pertained to the assessment of the effects of radiation on maxillofacial structures, including bone architecture alterations, periodontal space widening, teeth development abnormalities, osteoradionecrosis, and implant bone loss. The number of participants evaluated ranged from 8 to 176. Conclusion: The interaction between ionizing radiation and maxillofacial structures results in hazard to the tissues involved, particularly the bone tissue, periosteum, connective tissue of the mucosa, and endothelium. Hard tissue changes due to radiation therapy can be detected on panoramic radiographs.

Dental Radiography for Age Estimation: A Scoping Review

  • Jeon, Kug Jin;Kim, Young Hyun;Lee, Joo-Young;Jung, Hoi In;Han, Sang-Sun
    • Journal of Korean Dental Science
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    • 제15권1호
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    • pp.31-50
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    • 2022
  • Purpose: This study was to investigate the types of imaging modalities, analytical methods for age estimation, and the age of the subjects in research on age estimation using dental radiography through a scoping review, and to investigate the overall trends in age estimation studies. Materials and Methods: A scoping review was designed according to the Arksey and O'Malley guidelines and the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) statement. Three electronic databases were used as search sources (Medline, Embase, and Cochrane Library). Studies were classified according to the three main components of the research question. "What are the imaging modalities, analytical methods, and target age in dental imaging-based age estimation studies?" Result: The final 198 studies were selected by two reviewers. The most common imaging modality used in studies was panoramic radiography (69.7%), and studies using cone-beam computed tomography have increased over time. Analytical methods for age estimation were 62.6% in studies based on tooth development and 26.3% in studies using pulp/tooth ratio. The subject age was 27.8% for children and 27.3% for adults. Studies conducted in all age groups comprised the smallest category (5.2%). Conclusion: Panoramic radiography has been the most used types of imaging modalities for age estimation, and the most common analytical method was analysis of tooth development. Most studies targeted specific ages, and very few involved all age groups. Dental age estimation studies should be carried out with appropriate consideration of the imaging modality that is analyzed, the methods that are used, and the age that is targeted.

Health Perceptions of Police Officers in Korea: An Investigative Study

  • Dongmin Lee;Seohyun Park;Byeong Kwan Woo;Yeon-Cheol Park;Jion Kim
    • Journal of Acupuncture Research
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    • 제41권
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    • pp.149-159
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    • 2024
  • Background: Police officers are an occupational group with a high risk of developing musculoskeletal, cardiovascular, and mental diseases because of the nature of their work. This study aimed to gain an understanding of job-related health risks by comparing overall health awareness, presence of physical and mental disabilities and their causes, medical use patterns, and quality of life of the general public through a survey. Methods: In this comparative study, police officer data were collected through a survey conducted from October 1, 2022, to November 15, 2022, and general public data from the 8th National Health and Nutrition Examination Survey of Korea were used for comparison. Results: Police officers' health perception of physical or mental disabilities was significantly more negative than that of the general public because of their work characteristics, patterns, and functions. In addition, police officers with disabilities had severe work and daily living limitations, and their awareness of their overall quality of life was low enough to warrant alarm. Despite their high rates of seeking treatment in medical institutions, continuous medical use was limited. Conclusion: More research on major diseases to which police officers are at risk of exposure is necessary to analyze risk factors and accumulate related data to systematize health management. In addition, Korean medicine treatment techniques with excellent disease prevention are recommended for the health management of police officers.

Sustained release of alginate hydrogel containing antimicrobial peptide Chol-37(F34-R) in vitro and its effect on wound healing in murine model of Pseudomonas aeruginosa infection

  • Shuaibing Shi;Hefan Dong;Xiaoyou Chen;Siqi Xu;Yue Song;Meiting Li;Zhiling Yan ;Xiaoli Wang ;Mingfu Niu ;Min Zhang;Chengshui Liao
    • Journal of Veterinary Science
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    • 제24권3호
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    • pp.44.1-44.17
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    • 2023
  • Background: Antibiotic resistance is a significant public health concern around the globe. Antimicrobial peptides exhibit broad-spectrum and efficient antibacterial activity with an added advantage of low drug resistance. The higher water content and 3D network structure of the hydrogels are beneficial for maintaining antimicrobial peptide activity and help to prevent degradation. The antimicrobial peptide released from hydrogels also hasten the local wound healing by promoting epithelial tissue regeneration and granulation tissue formation. Objective: This study aimed at developing sodium alginate based hydrogel loaded with a novel antimicrobial peptide Chol-37(F34-R) and to investigate the characteristics in vitro and in vivo as an alternative antibacterial wound dressing to treat infectious wounds. Methods: Hydrogels were developed and optimized by varying the concentrations of crosslinkers and subjected to various characterization tests like cross-sectional morphology, swelling index, percent water contents, water retention ratio, drug release and antibacterial activity in vitro, and Pseudomonas aeruginosa infected wound mice model in vivo. Results: The results indicated that the hydrogel C proved superior in terms of cross-sectional morphology having uniformly sized interconnected pores, a good swelling index, with the capacity to retain a higher quantity of water. Furthermore, the optimized hydrogel has been found to exert a significant antimicrobial activity against bacteria and was also found to prevent bacterial infiltration into the wound site due to forming an impermeable barrier between the wound bed and external environment. The optimized hydrogel was found to significantly hasten skin regeneration in animal models when compared to other treatments in addition to strong inhibitory effect on the release of pro-inflammatory cytokines (interleukin-1β and tumor necrosis factor-α). Conclusions: Our results suggest that sodium alginate -based hydrogels loaded with Chol-37(F34-R) hold the potential to be used as an alternative to conventional antibiotics in treating infectious skin wounds.

미생물법의학: 차세대염기서열분석 방법에 따른 MLVA 결과 비교 및 이를 활용한 DNA 감식 (Microbial Forensics: Comparison of MLVA Results According to NGS Methods, and Forensic DNA Analysis Using MLVA)

  • 윤형석;이승호;임승현;이대상;구세훈;김정은;정주환;김성주;허경행;송동현
    • 한국군사과학기술학회지
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    • 제27권4호
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    • pp.507-515
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    • 2024
  • Microbial forensics is a scientific discipline for analyzing evidence related to biological crimes by identifying the origin of microorganisms. Multiple locus variable number tandem repeat analysis(MLVA) is one of the microbiological analysis methods used to specify subtypes within a species based on the number of tandem repeat in the genome, and advances in next generation sequencing(NGS) technology have enabled in silico anlysis of full-length whole genome sequences. In this paper, we analyzed unknown samples provided by Robert Koch Institute(RKI) through The United Nations Secretary-General's Mechanism(UNSGM)'s external quality assessment exercise(EQAE) project, which we officially participated in 2023. We confirmed that the 3 unknown samples were B. anthracis through nucleic acid isolation and genetic sequence analysis studies. MLVA results on 32 loci of B. anthracis were analysed by using genome sequences obtained from NGS(NextSeq and MinION) and Sanger sequencing. The MLVA typing using short-reads based NGS platform(NextSeq) showed a high probability of causing assembly error when a size of the tandem repeats was grater than 200 bp, while long-reads based NGS platform(MinION) showed higher accuracy than NextSeq, although insertion and deletion was observed. We also showed hybrid assembly can correct most indel error caused by MinION. Based on the MLVA results, genetic identification was performed compared to the 2,975 published MLVA databases of B. anthracis, and MLVA results of 10 strains were identical with 3 unkonwn samples. As a result of whole genome alignment of the 10 strains and 3 unknown samples, all samples were identified as B. anthracis strain A4564 which is associated with injectional anthrax isolates in heroin users.

3차원 전산화단층찰영 영상을 이용한 얼굴 연조직 두께 계측 (Measurement of facial soft tissues thickness using 3D computed tomographic images)

  • 정호걸;김기덕;한승호;신동원;허경석;이제범;박혁;박창서
    • Imaging Science in Dentistry
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    • 제36권1호
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    • pp.49-54
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    • 2006
  • Purpose : To evaluate accuracy and reliability of program to measure facial soft tissue thickness using 3D computed tomographic images by comparing with direct measurement. Materials and Methods : One cadaver was scanned with a Helical CT with 3 mm slice thickness and 3 mm/sec table speed. The acquired data was reconstructed with 1.5 mm reconstruction interval and the images were transferred to a personal computer. The facial soft tissue thickness were measured using a program developed newly in 3D image. For direct measurement, the cadaver was cut with a bone cutter and then a ruler was placed above the cut side. The procedure was followed by taking pictures of the facial soft tissues with a high-resolution digital camera. Then the measurements were done in the photographic images and repeated for ten times. A repeated measure analysis of variance was adopted to compare and analyze the measurements resulting from the two different methods. Comparison according to the areas was analyzed by Mann-Whitney test. Results : There were no statistically significant differences between the direct measurements and those using the 3D images (p>0.05). There were statistical differences in the measurements on 17 points but all the points except 2 points showed a mean difference of 0.5 mm or less. Conclusion : The developed software program to measure the facial soft tissue thickness using 3D images was so accurate that it allows to measure facial soft tissues thickness more easily in forensic science and anthropology.

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스마트 홈 헤이 홈 Air의 클라우드 아티팩트 원격 수집 방안 연구 (A Study on the remote acuisition of HejHome Air Cloud artifacts)

  • 김주은;서승희;차해성;김역;이창훈
    • 인터넷정보학회논문지
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    • 제23권5호
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    • pp.69-78
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    • 2022
  • IoT(Internet of Things) 디바이스의 사용이 확대됨에 따라 경찰청의 디지털 포렌식 적용 범위가 스마트 홈 영역으로 확대되었다. 이에 따라 스마트 홈 플랫폼 데이터를 수집하기 위해 진행된 기존 연구들은 대부분 모바일 기기의 로컬 데이터 분석과 네트워크 관점의 분석 등의 연구가 주로 수행되었다. 하지만 증거 분석을 위해 유의미한 데이터는 스마트 홈 플랫폼의 클라우드 스토리지에 주로 저장되어있다. 따라서 본 논문에서는 사용자가 헤이 홈 앱 기반의 "헤이 홈 스퀘어" 서비스를 이용할 때 PC에 기록되는 Microsoft Edge, Google Chrome, Mozilia Firefox, Opera와 같은 웹 브라우저들의 쿠키 데이터베이스를 통해 사용자 계정의 accessToken을 획득하여 헤이 홈 Air 환경에서 클라우드에 저장된 데이터의 수집 방안을 연구했다. 데이터는 헤이 홈의 모회사가 제공하는 OpenAPI를 활용해 클라우드로 직접 접근하여 수집하였다. 본 논문에서는 스마트 온·습도 센서, 스마트 도어 센서, 스마트 모션 센서로 환경을 구성하여 실험를 수행했고 날짜 및 장소별 온·습도 데이터, 사용한 디바이스 리스트, 방 내 모션 감지 기록 등의 아티팩트를 수집할 수 있는 것을 확인하였다. 이와 같은 아티팩트 분석 결과를 통해 알 수 있는 사건 당시의 온·습도 등의 정보는 포렌식 수사 과정에서 단서로 활용될 수 있다. 또한 본 논문에서 제안한 OpenAPI를 활용한 클라우드 데이터 수집 방안은 데이터 수집 과정에서 발생할 수 있는 변조 가능성을 배제하고, API를 이용해 결과를 호출하기 때문에 디지털 포렌식의 원칙인 무결성의 원칙과 재현성의 원칙을 따른다.

강도 범죄의 실태 및 대구 지역 침입 강도 범죄 분석 (Actual Conditions of Burglaries and Analysis on Residential Invasion Burglaries in Daegu Area)

  • 이상호;곽정식
    • 대한수사과학회지
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    • 제2권2호
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    • pp.5-20
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    • 2007
  • 2001년부터 2005년까지 5년 동안 우리나라에서 발생한 강도사건은 모두 29,892 건으로 연 평균 약 5,978 건이 발생하였는데, 그 분석결과를 요약하면 다음과 같다. 수법은 침입강도가 8,605 건(28.8%)으로 가장 많았고, 침입구는 출입문이 4,031 건(64.3%)으로 가장 많았으며, 침입 방법은 문단속이 없는 출입문이나 창문을 통하여 침입한 것이 2,462 건(28.6%)으로 가장 많았고, 발생시간은 심야시간대 (00:00~04:00사이)가 가장 많았으며, 요일별로 보면 수요일이 5,652건으로, 일요일(2,988건)의 약 2 배가량 많이 발생한 것으로 나타났다. 강도범죄로 인해 신체적 피해를 입은 피해자는 사망 260 명, 상해 10,610 명으로 나타났으며, 발생장소는 노상(路上)이 10,183건(34%)으로 가장 많았고, 그 다음이 주거지로서 7,527 건(약25%)이 발생한 것으로 나타났다. 공범관계는 단독범이 15,012 명(56.1%)으로 가장 많았고, 범행시 범행도구는 소지하지 않음이 15,631건(58.4%)으로 가장 많았으나, 소지한 범행도구 중에는 칼이 6,498 건(24.3%)으로 가장 많았다. 2001년부터 2006년까지 6년 동안 대구지역에서 발생한 강도범죄는 모두 1,506 건으로 연평균 251 건이었으며, 이중 침입강도 사건은 515 건(34.2%)으로 연평 균 약 86 건이 발생하였는데, 발생시간은 역시 심야시간대(00:00~04:00사이)에서 가장 많이 발생(194 건, 37.7%)하였고, 침입 장소는 주거지(259 건, 50.3%)가 가장 많았으며, 침입구는 출입문(87 건, 33.6%)이 가장 많았고, 침입방법은 문단속이 없는 출입문이나 창문으로 침입한 것이(65 건, 25.1%) 가장 많은 것으로 나타났다. 그 외에 택배원 등 방문자로 가장하거나 피해자를 뒤따라 침입하는 수법도 26 건(10%)이 발생한 것으로 나타났다. 이러한 강도범죄 예방을 위해서는 국가적, 사회적 대책은 물론, 개인의 자위 방범활동도 상당히 중요한 부분을 차지한다는 것을 알 수 있었는데, 특히, 침입강도 범죄자가 시정되지 않은 출입문이나 창문을 통하여 가장 많이 침입한다는 분석결과를 볼 때 범죄예방에 대한 인식이나 노력이 많이 부족하다는 것을 알 수 있었다. 범죄예방을 위한 가장 기본적인 방법 중의 하나가 문단속이라는 사실을 모르는 사람이 없을 것임에도, 이러한 기본적인 방법조차 실행하지 않아 강도범죄의 피해자가 된다는 것이 그것을 뜻한다. 따라서 본 연구에서 나타난 강도범죄의 실태를 참고하여 범죄예방에 대한 관심을 가짐으로써 강도범죄의 피해자가 한 사람이라도 줄어 들었으면 한다. 최근 과학수사에 대한 사회전반의 인식향상에 따라 경찰기관에서도 범죄분석요원, 피해자심리상담요원, 검시관 등을 특별채용하여 각 종 범죄분석 등 과학수사의 발전 기반이 마련되고 있다. 이를 토대로 범죄예방을 위한 심도있는 연구가 더욱 활발하게 이루어지기를 기대한다.

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안드로이드 환경의 OAuth 프로토콜을 이용한 원격지 데이터 수집 방법 연구 (Study on Remote Data Acquisition Methods Using OAuth Protocol of Android Operating System)

  • 남기훈;공성현;석병진;이창훈
    • 정보보호학회논문지
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    • 제28권1호
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    • pp.111-122
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    • 2018
  • 안드로이드 운영체제의 서드파티 애플리케이션들은 사용자의 계정 및 개인정보에 대한 접근 권한을 획득하기 위해 OAuth 프로토콜을 이용하여 계정 정보 제공자들로부터 사용자의 크리덴셜 및 사용자의 자원에 접근할 수 있는 권한을 내포하는 접근 토큰을 전달받는다. 이러한 크리덴셜 및 토큰 정보는 안드로이드 운영체제가 제공하는 OAuth 관련 데이터 관리 방식에 의해 기기 내부에 저장되는데, 이 정보가 유출될 경우 공격자는 유출된 크리덴셜 및 토큰 정보를 이용하여 사용자의 계정에 대한 자유로운 로그인 및 데이터 접근이 가능하다. 이러한 특징은 디지털 포렌식 수사관이 증거 데이터를 수집하는 관점에서 피압수자가 사용하는 서비스의 원격지 서버로부터 직접 데이터를 수집하는 것을 가능하게 한다. 원격지에서 수집되는 증거 데이터는 2차적인 영장발부의 토대로 작용함으로써 수집한 디지털 증거의 증거능력을 확보할 수 있기 때문에 피압수자가 안드로이드 기기에서 애플리케이션 삭제 등의 증거 인멸을 시도한 경우 매우 중요한 증거가 될 수 있다. 본 논문에서는 다양한 안드로이드 운영체제 및 기기 환경에서 OAuth 토큰의 관리 현황을 분석하고, 이를 이용하여 다양한 서드파티 애플리케이션의 데이터를 수집하는 방법을 소개한다. 이를 통해 디지털 포렌식 관점에서 피압수자가 사용하는 서비스의 원격지 데이터를 수집함으로써 증거 수집의 영역을 확장할 수 있는 방안을 제안한다.