• 한국전산구조공학회논문집
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• 제34권4호
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• pp.183-189
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• 2021

구조물에 장기적으로 발생하는 노후화를 정량적으로 파악하기 위해 상시진동 데이터를 활용한 일반화된 모니터링 시스템에 관한 연구가 세계적으로 활발히 수행중이다. 본 연구에서는 구조물에서 장기적으로 취득되는 동특성을 앙상블 학습에 활용하여 구조물의 이상을 감지하기 위한 보급형 엣지 컴퓨팅 시스템을 구축하였다. 시스템의 하드웨어는 라즈베리파이와 보급형 가속도계, 기울기센서, GPS RTK 모듈, 로라 모듈로 구성됐다. 실험실 규모의 구조물 모형 진동실험을 통해 동특성을 활용한 앙상블 학습의 구조물 이상감지를 검증하였으며, 실험을 기반으로 한 실시간 동특성 추출 분산처리 알고리즘을 라즈베리파이에 탑재하였다. 구축된 시스템을 하우징하고 포항시 행정복지센터에 설치하여 데이터를 취득함으로써 개발된 시스템의 현장 적용성을 검증하였다.

• 한국음향학회지
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• 제40권6호
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• pp.537-545
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• 2021

인간에 의한 연안 지역 개발 및 변형의 가속화로 인해 해양포유류에 대한 피해가 우려되고 있다. 연안 개발이 해양포유류에 어떤 영향을 미칠 수 있는지 이해하려면 이들의 분포를 파악하는 것이 중요하다. 본 연구에서는 서남해 해상풍력 실증단지에서 수동 음향 관측을 통해 상괭이의 출현을 확인하였다. 실험지역에서의 상괭이에 대한 목시관측 결과가 없으므로, 풍력단지에서 탐지된 클릭은 상괭이 발견율이 높은 지역에서 측정한 클릭과 음향특성을 비교하여 검증하였다. 음향 측정 결과에 의하면 상괭이는 매일 출몰하였으며, 평균 클릭수는 40.7회, 상괭이의 출현 비율은 9.7 %, 출현 시간은 18.2 min이며, 대기 시간은 94.9 min으로 나타났다. 이 연구를 통해 서남해 해상풍력 실증단지에서 알려지지 않은 상괭이 출현에 대한 정보를 제공하였으며, 이러한 결과는 풍력단지 운영으로 인한 해양포유류의 영향을 모니터링하는데 도움을 줄 수 있다.

• Journal of the Korean Wood Science and Technology
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• 제50권5호
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• pp.301-314
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• 2022

The moisture and dimensional behaviors of a nail-laminated timber (NLT)-concrete slab composed of an NLT-plywood composite and topping concrete are monitored for 385 days. The slab is developed for using as flexural elements such as floors. The humidity control of wood gently introduces significant fluctuations under the ambient relative humidity into the slab, and fluctuations in the relative humidity result in dimensional changes. The equilibrium moisture content of the slab increases from 6.7% to 15.3% during the monitoring period, resulting in a width (radial) strain of 0.58%. The length (longitudinal) strain is negligible, and the height (tangential) strain is excluded from the analysis because of abstruse signal patterns generated. Concrete pouring causes a permanent increase in the width of the NLT-plywood composite. However, the width deforms because the weight of the concrete mixture loosens the nail-laminated structure, not because of the significant amount of moisture in the mixture. The dimensional stabilization effect of the nail-laminated system is demonstrated as the composite strain is lower than the total strain of lumber and plywood, which are elements constituting the nail-laminated structure.

• 보건행정학회지
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• 제33권1호
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• pp.29-39
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• 2023

Background: Breaking the chain of disease transmission from overseas is necessary to control new infectious diseases such as coronavirus disease 2019 effectively. In this study, we developed a mobile app called Self-Symptom Checker (SSC) to monitor the health of inbound travelers. Methods: SSC was developed for general users and administrators. The functions of SSC include non-repudiation using QR (quick response) codes, monitoring fever and respiratory symptoms, and requiring persons showing symptoms to undergo polymerase chain reaction tests at nearby screening stations following a review of reported symptoms by the Korea Disease Control and Prevention Agency, as well as making phone calls, via artificial intelligence or public health personnel, to individuals who have not entered symptoms to provide the necessary information. Results: From February 12 to March 27, 2020, 165,000 people who were subjected to the special entry procedure installed SSC. The expected number of public health officers and related resources needed per day would be 800 if only the phone was used to perform symptom monitoring during the above period. Conclusion: By applying SSC, more effective symptom monitoring was possible. The daily average number of health officers decreased to 100, or 13% of the initial estimate. SSC reduces the work burden on public healthcare personnel. SSC is an electronic solution conceived in response to health questionnaires completed by inbound travelers specified in the World Health Organization International Health Regulations as a requirement in the event of a pandemic.

• 한국수자원학회논문집
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• 제56권11호
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• pp.729-735
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• 2023

다중분광센서인 Moderate resolution Imaging Spectroradiometer (MODIS)는 지표 및 대기 산출물을 통해 다양한 분야에서 활발한 연구가 진행되어 왔다. MODIS는 발사된지 20년이 지났고, 비슷한 특성의 이를 대체할 만한 자료의 필요성이 지속적으로 제기되어 왔다. 본 연구에서는 2011년에 발사된 Suomi National Polar-orbiting Partnership (Suomi NPP) 위성의 Visible Infrared Imaging Radiometer Suite (VIIRS) sensor에서 제공하는 지표 산출물 중 지표면 온도(Land Surface Temperature, LST)와 식생 지수인 정규식생지수(Normalized Differences Vegetation Index, NDVI)를 소개하고, 기존의 MODIS에서 제공되는 자료와의 비교 및 검증을 통해 연구 지역인 남한에서의 지역적인 적용성을 파악하고자 한다. 지표면 온도와 식생 활력은 농업적인 가뭄을 발생시키는 주요한 인자로써, 남한의 극심한 가뭄기간인 2014년과 2015년을 대상으로 가뭄의 시공간적인 변동성을 분석하여, VIIRS 산출물의 활용 가능성을 파악하였다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권6호
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• pp.498-510
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• 2001

Distraction osteogenesis refers to the biological process responsible for new bone formation between bone segments by gradual distraction after osteotomy. For the past several years, various inconveniences including a protracted consolidation period that requires patients to wear a distractor frame longer, as well as higher medical costs, have not been remedied by improvements in osteotomy, distraction rate and monitoring system. Furthermore, side effects such as pin tract infections and soft tissue swelling may arise due to the long treatment period. These drawbacks form the rationale of this study which purports to seek a method by which the consolidation period can be reduced. This paper examines how platelet-rich plasma(PRP), known to facilitate osteogenesis, influences bone formation when applied in distracted area. Ten mongrel dogs, which were made to wear external distractor frames after osteotomy in both sides of the mandible, were used as subjects. After a 7day period of latency, distraction was carried out at a rate of 1mm/day for 14 consecutive days. After the onset of distraction, 2ml of PRP and a mixture of calcium gluconate and thrombine were injected into the center of the distracted callus on the left side of the mandible. The left was injected with PRP while the right side was set as the control site without PRP treatment. Execution at the onset of distraction and in 2 weeks, 4 weeks and 8 weeks after the consolidation period, clinical and radiographic tests, bone mineral density examination, histological examination and histomorphometric analysis were conducted to compare both sides. The results are summarized as follows: 1. Based on the clinical examination at two weeks, more remarkable cortical bone formation was found on the buccal and lingual side of the distracted area in the PRP treatment site than in the control site. No visual difference was found between the PRP treatment site and the control site at four eight weeks. 2. Based on the radiological examination, a distinct increase in the radiopaque appearance of the PRP treatment site was revealed at two weeks, but this increase appeared to slow down at four and eight weeks. 3. Examination of bone mineral density revealed a significant difference at two weeks with the PRP treatment site yielding density two times higher than the control site. This difference lessened after four weeks, and disappeared at eight weeks. 4. The histomorphometric examination revealed that about 20% more bony trabeculae area(20%, higher) was formed in the PRP treatment site than in the control site. In conclusion, it can be said that PRPs effect on stimulating bone formation in the PRP treatment site manifest as early as two weeks. Trabeculae formation likewise increased throughout the whole period. If this result can be applied to humans, the consolidation period can be reduced by injecting PRP into the distracted area.

• 한국토양비료학회지
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• 제48권6호
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• pp.641-647
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• 2015

Monitoring of soil fertility by long-term application of fertilizers is necessary to improve the fertility of soil and the productivity of crop. The objective of this study was conducted to investigate the changes of exchangeable Mg by continuous application of fertilizers from 1969 to 2014. The treatments were no fertilization (No fert.) and fertilization (NPK, NPK+C, NPK+S, and NPK+CS). The concentration of exchangeable Mg in No fert., NPK+C, and NPK+S treatments tended to increase from 1965 to 1975, but decrease gradually from 1976 to 1987, and increase again after 1988. Based on these, the changes of exchangeable Mg were divided into period I ('69 ~'75), period II ('76~'87), and period III ('88~'14). Especially, exchangeable Mg decreased in the period II. This was presumed that a significant amount of Mg from topsoil were leached into subsoil by break of plow pan and some of subsoil was incorporated into topsoil according to change of plowing depth by replacement of tillage machinery. It could be possible that exchangeable Mg in NPK, NPK+S, and NPK+CS was accumulated in the depth of 15~20 cm. For the period III, exchangeable Mg in No fert., NPK, NPK+C, NPK+S, and NPK+CS treatments increased at rates of 0.013, 0.018, 0.015, 0.023, and $0.024cmolckg^{-1}{\cdot}yr^{-1}$ respectively. Exchangeable Mg level in NPK+S was lower than the other treatments in the period I and period II, but higher than in the period III. This result was attributed to replacement of silicate fertilizer type from wollastonite (Mg 0.3%) to silicate fertilizer (Mg 3%). Also, exchangeable Mg level of No fert. treatment increased, which showed that Mg concentration of irrigated water had the greatest impact on Mg accumulation of soil. Recently, Mg level of irrigated water tended to increase, indicating that Mg concentration of water will affect greatly the concentration of exchangeable Mg of soil in the future. Like these, the changes of exchangeable Mg were greatly influenced by agricultural environment such as plowing depth, plow pan, content of fertilizer, and quality of irrigated water. Considering these agricultural environment, the proper management of soil is needed for the improvement of soil fertility and crop productivity.

• 한국의료질향상학회지
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• 제5권2호
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• pp.224-237
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• 1998

Background : This is an investigative study to analyse the importance of works perceived by Quality Improvement(QI) Coordinators and to evaluate their current work performances using the questionnaires developed by the investigator. Methods : The data were collected from 37 subjects over two weeks period from Oct. 1 to Oct. 17, 1998 and analysed by the descriptive statistics of SPSS program. The items of questionnaire are consisted of 13 work domains including 73 activities based on Quality Management(QM) Coordinator's job description of National Association for Healthcare Quality:data collection & analysis, communication, monitoring, evaluation, accreditation, tool development, policy development, program development, self development, education & trainning, system design, planning, and consultation & support. Results : 1) Of the performances in 13 work domains, the frequencies of the work performed were accreditation(89%), planning(88%), communication(83%), data collection & analysis(82%), monitoring(76%), policy development(72%), consultation & support (71%), education & trainning(70%), self development(68%), evaluation(63%), tool development(61%), program development(44%) and system design(43%) in order. 2) For the importances (1=not important, 5=very important), the policy development(4.46) scored highest then monitoring(4.42), planning(4.41), education & trainning(4.38), communication(4.35), evaluation(4.34) tool development (4.30), data collection & analysis(4.29), program development(4.22), consultation & support(4.22), accreditation(4.15), self development(4.05) and system design(3.98) in order. 3) There was a difference between the work performance and the perceived importance. The results showed the low performances in policy development, monitoring, education & trainning and evaluation which ranked high by the perceived importance and the high performances in accreditation, data collection & analysis, self development, communication and consultation & support which ranked middle to low by the perceived importance. 4) The reasons for low performances of QI Coordinators were the lack of clear assignment for the responsibility and allowed authority for work to QI Coordinators(30.8%), insufficient member of QI Coordinators(13.9%), lack of hospital director's interest(11.5%), low motivation of QI Coordinators (10.6%) and insufficient knowledge & experience of QI Coordinators (8.8%). Conclusion : Most works were perceived important by QI Coordinators, but there was a difference in the work performance. The works performed over 70% were related with accreditation, data collection & analysis, communication, planning and monitoring, on the other hand under 50% in performances were related with system design, program development, tool development and evaluation.

• 지구물리와물리탐사
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• 제16권4호
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• pp.217-224
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• 2013

모델변수의 증감 및 분해능을 고려하는 새로운 교차모델 제한자를 사용한 시간경과 역산 알고리듬을 개발하였다. 증감을 고려한 교차모델 제한자는 같은 변화비를 갖는 모델변수에 같은 제한을 가한다. 이 교차모델 제한자는 모델변수의 증감에 관계없이 의미 있는 변화를 보이는 모델변수들을 강조할 수 있다. 분해능 교차모델 제한자는 분해능이 낮은 모델변수에 작은 제한을 가하는 반면, 분해능이 높은 모델변수에는 큰 제한을 가한다. 따라서 분해능이 낮은 모델변수도 시간 경과에 따라 의미 있는 변화를 보일 경우 효과적으로 식별할 수 있다. 3차원 전기비저항 모니터링 자료의 수치실험을 통하여 이들 두 교차모델 제한자의 타당성을 검증하였다. 최종적으로, 방조제의 안정성 평가를 위하여 서해안에 위치한 방조제에서 얻은 3 차원 전기비저항 모니터링 자료의 처리에 개발된 시간경과 역산법을 적용하였다. 시간경과 역산의 결과 모니터링이 수행된 기간 동안 방조제에 주목할 만한 변화가 없는 것으로 해석되었다.

• 한국융합학회논문지
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• 제9권1호
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• pp.419-431
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• 2018

본 논문은 개인 사용자의 트윗을 분석하여 사용자의 감정 흐름을 모니터링할 수 있는 새로운 방법을 제안한다. 본 논문에서는 사용자의 감성 흐름을 정확하게 예측하기 위해서 기존의 텍스트 위주의 시스템과 달리 본 연구에서는 사용자가 쓴 텍스트와 영상 등으로부터 감성을 인식하는 멀티 모달 분석 기법이 개발된다. 제안된 방법에서는 먼저 어휘분석 및 문맥을 이용한 텍스트분석기와 학습기반의 영상감성인식기를 이용하여 텍스트 및 영상 트윗에 숨겨진 개별 감성을 추출한다. 이후 이들은 규칙기반 통합 방법에 의해 날짜별로 통합되고, 마지막으로 개인의 감성흐름을 보다 직관적으로 관측할 수 있도록 감성흐름그래프로 시각화한다. 제안된 방법의 효용성을 평가하기 위해 두 단계의 실험이 수행되었다. 먼저 4만여 개의 트윗으로부터 제안된 방법의 정확도 평가 실험이 수행되고, 최신 트윗 분석 기술과 비교 분석되었다. 두 번째 실험에서는 40명의 우울증을 가진 사용자와 일반사용자를 구분할 수 있는지에 대한 실험이 수행된 결과, 제안된 기술이 실제 사용자의 감성흐름을 모니터하는데 효율적임을 증명하였다.