• 대한한방소아과학회지
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• 제38권2호
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• pp.32-40
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• 2024

Objectives The main aim was to quantify forward head posture using POM Checker®, a postural balance analyzer, among elementary school students. Additionally, the study aimed to investigate whether postural imbalance improved following three sessions of the school doctor program focused on body posture correction. Methods The program was conducted as part of the school doctor program in Korean Medicine, featuring lectures by a designated Korean Medicine doctor at an elementary school. The curriculum covered the importance of maintaining correct posture and included posture correction exercises. Pre- and post-program self-reported surveys were administered, alongside postural measurements taken over three months at one-month intervals. The survey included data on gender, grade, lifestyle habits, and awareness of correct posture. Result Out of 73 participating students, 63 underwent body balance measurements from the upper grades of one elementary school. Survey results revealed significant variations in daily sitting hours and weekly exercise levels. Attendance at lectures increased knowledge about correct posture. Initial measurements of forward head posture categorized 41.0% and 1.6% of participants into caution and risk groups, respectively. After the second measurement, the caution group representation decreased to 3.2%, and by the third measurement, only 1.6% of participants remained in the caution group. Conclusions Improvements in the angle and understanding of forward head posture among elementary school students were observed before and after the Korean Medicine school doctor program. However, posture improvement may be temporary, necessitating consistent follow-up management and monitoring.

• 감성과학
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• 제26권4호
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• pp.41-50
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• 2023

본 연구는 EMG(electromyography) 텍스타일 전극 개발을 목적으로 레이어 수의 디자인 및 원단을 다르게 하여 성능 및 신호 획득 안정성을 평가한다. 레이징 및 프레스 공정을 통하여 텍스타일 전극을 제조하며 Layer-0, Layer-1, Layer-2로 레이어 유무 및 수에 따른 결과를 분석했다. 이에 레이어 유무에 따라서는 근활성 측정에 영향을, 수가 많을수록 높은 성능이 나타남을 확인할 수 있었다. Layer-2 구조로 통일하여 5가지의 원단(네오프렌, 스판덱스 쿠션, 폴리에스테르 100%, 나일론 스판덱스, 광목 캔버스)으로 전극을 제조해 실험해 보았다. 성능적인 면에서, 원단의 중량이 높은 나일론 스판덱스가 높은 성능을 보였으며, 스판쿠션 텍스타일 전극이 근활성도 수득에 높은 안정성을 보였다. 이에 위 연구는 레이어에 따른 성능 연관성과 전극-피부사이의 닿는 면적 간의 관계 등을 고찰하여 슬리브 전체의 의복압을 늘리는 대신 특정 센서 측정 부위에만 높은 압력을 가함으로 차후 연구에서 레이어의 수 및 물성에 따른 전극의 공학적 설계 가능성을 제시한 의의가 있다.

• 한국항행학회논문지
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• 제27권6호
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• pp.770-775
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• 2023

최근 디지털 데이터 양의 기하급수적 증가는 데이터 처리 시스템의 중요성을 부각시켰다. 이 연구는 클라우드 컴퓨팅 (CC; cloud computing), 엣지 컴퓨팅 (EC; edge computing), 그리고 UAV (unmanned aerial vehicle) 기반 지능형 에지 컴퓨팅 (UEC; unmanned aerial vehicle-based intelligent edge computing) 간의 성능을 비교하였으며, 특히 회랑감시와 같은 실시간 대용량 데이터 처리 상황에 초점을 맞추었습니다. UAV 기반 지능형 에지 컴퓨팅은 이동성과 특수 환경에서의 대규모 데이터 처리 및 분석에 높은 효과성을 보인다. 이러한 연구 결과를 바탕으로 각 상황에 맞게 최적화된 시스템 선택 방법론을 제안한다.

• 대한조선학회논문집
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• 제61권1호
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• pp.8-18
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• 2024

The present study concerns reduced order modeling of a marine diesel engine, which can be used for outlier detection in status monitoring and carbon intensity index calculation. Principal Component Analysis (PCA) is introduced for the reduced order modeling, focusing on the feasibility of detecting and treating nonlinear variables. By cross-correlation, it is found that there are seven non-linear data channels among 23 data channels, i.e., fuel mode, exhaust gas temperature after the turbocharger, and cylinder coolant temperatures. The dataset is handled so that the mean is located at the nominal continuous rating. Polynomial presentation of the dataset is also applied to reflect the linearity between the engine speed and other channels. The first principal mode shows strong effects of linearity of the most data channels to show the linearity of the system. The non-linear variables are effectively explained by other modes. second mode concerns the temperature of the cylinder cooling water, which shows small correlation with other variables. The third and fourth modes correlates the fuel mode and turbocharger exhaust gas temperature, which have inferior linearity to other channels. PCA is proven to be applicable to data given in binary type of fuel mode selection, as well as numerical type data.

• 대한원격탐사학회지
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• 제40권2호
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• pp.151-166
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• 2024

해안쓰레기 문제는 전 세계적으로 환경에 대한 심각한 위협이 되고 있다. 본 연구에서는 딥러닝과 원격탐사 기술을 활용하여 해안쓰레기의 모니터링 방법을 개선하고자 하였다. 이를 위해 You Only Look Once (YOLO)v8 모델을 이용한 객체 탐지 기법을 적용하여 우리나라 주요 해안쓰레기 11종에 대한 대규모 이미지 데이터셋을 구축하고, 실시간으로 쓰레기를 탐지 및 분석할 수 있는 프로토콜(Protocol)을 제안한다. 낙동강 하구에 위치한 신자도를 대상으로 드론 이미지 촬영 및 자체 개발한 YOLOv8 기반의 분석 프로그램을 적용하여 해안쓰레기 성상별 핫스팟을 식별하였다. 이러한 매핑(Mapping) 및 분석 기법의 적용은 해안쓰레기 관리에 효과적으로 활용될 수 있을 것으로 기대된다.

• 한국물환경학회지
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• 제40권1호
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• pp.1-10
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• 2024

Algal blooms occur seasonally in the eutrophicated rivers or reservoirs, and some harmful cyanobacteria species produce toxic substances, which are directly or indirectly harmful to the ecosystem and terrestrial animals. So, the monitoring and control of harmful cyanobacteria occurrence and toxins residual in the aquasystem are important to preserve the water environment and secure public health. In this study, the four harmful cyanobacteria occurrences and toxic substance concentrations of two agricultural reservoirs in the southern part of Gyeonggi Province were investigated from August to October 2022. Among four harmful cyanobacteria (Microcystis sp., Anabaena sp., Oscillatoria sp., Aphanizomenon sp.), three kinds of cyanobacteria except Oscillatoria sp. were observed, and Microcystis sp. was the dominant cyanobacteria except for Anabaena sp. dominant result of a sample collected on October at reservoir B. The cell density of cyanobacteria was influenced by season and weather due to the length of daytime and concentrations of organic carbon and nitrogen. Three kinds of microcystin and anatoxin-a were quantitatively analyzed as total (in the cell body and water) and extracellular (in water) concentrations. The maximum total concentrations of anatoxin-a, microcystin-LR, microcystin-RR, and microcystin-YR were 0.1291 ㎍/L, 0.2776 ㎍/L, 0.3721 ㎍/L, and 0.0306 ㎍/L, respectively, in reservoir A and 0.3274 ㎍/L, 0.1495 ㎍/L, 0.2037 ㎍/L, and 0.0153 ㎍/L, respectively, in reservoir B.

• Journal of Yeungnam Medical Science
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• 제40권4호
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• pp.402-411
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• 2023

Background: We hypothesized that fatty liver disease (FLD) is associated with a high prevalence of hearing loss (HL) owing to metabolic disturbances. This study aimed to evaluate the association between FLD and HL in a large sample of the Korean population. Methods: We used a dataset of adults who underwent routine voluntary health checkups (n=21,316). Fatty liver index (FLI) was calculated using Bedogni's equation. The patients were divided into two groups: the non-FLD (NFLD) group (n=18,518, FLI <60) and the FLD group (n=2,798, FLI ≥60). Hearing thresholds were measured using an automatic audiometer. The average hearing threshold (AHT) was calculated as the pure-tone average at four frequencies (0.5, 1, 2, and 3 kHz). HL was defined as an AHT of >40 dB. Results: HL was observed in 1,370 (7.4%) and 238 patients (8.5%) in the NFLD and FLD groups, respectively (p=0.041). Compared with the NFLD group, the odds ratio for HL in the FLD group was 1.16 (p=0.040) and 1.46 (p<0.001) in univariate and multivariate logistic regression analyses, respectively. Linear regression analyses revealed that FLI was positively associated with AHT in both univariate and multivariate analyses. Analyses using a propensity score-matched cohort showed trends similar to those using the total cohort. Conclusion: FLD and FLI were associated with poor hearing thresholds and HL. Therefore, active monitoring of hearing impairment in patients with FLD may be helpful for early diagnosis and treatment of HL in the general population.

• 한국건설순환자원학회논문집
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• 제12권2호
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• pp.162-168
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• 2024

본 연구에서는 전기역학적 임피던스(electro-mechanical impedance, EMI) 센싱기법을 통해 플라이애시를 치환한 시멘트 페이스트의 응결시점을 평가하였다. 시멘트 중량대비 10 %, 20 %, 30 %를 플라이애시로 치환하여 물-바인더비 40 %의 시멘트 페이스트를 제조하였다. 제조된 시멘트 페이스트에 압전 센서를 매립하여 압전 센서의 EMI 신호변화를 연속적으로 모니터링하였다. EMI 센싱기법의 유효성을 검증하기 위해 비카트침 시험과 간이단열 온도시험을 동시에 수행하였다. 실험결과, 시멘트 페이스트의 응결구간에서 압전센서의 EMI 공진피크와 공진주파수에서 주목할 만한 변화가 나타났다. EMI 센싱기법에서 측정된 응결시간은 비카트침 시험과 간이단열 온도시험에서 측정된 응결시간과 상관관계가 있음을 확인하였다.

• 한국전산구조공학회논문집
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• 제37권3호
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• pp.197-204
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• 2024

본 논문에서는 조선 후기의 대표적인 전통목구조인 수원 화령전 운한각의 구조성능을 평가하였다. 운한각의 가구구성 방식에 맞추어 3차원 구조해석 소프트웨어인 midas Gen으로 해석모델을 정교하게 구축하였다. 정적해석으로 주요 구조부재의 안전성과 사용성을 평가하였고, 고유치해석으로 동적거동특성을 평가하였다. 대부분의 부재가 안전성 및 사용성 기준을 여유 있게 만족하고 있으나, 외목도리에서 휨응력비가 기준을 20.7% 초과하고 있어 이 부재에 대해서는 장기적인 모니터링이 필요하다고 사료된다. 운한각의 고유주기는 1.079초로 비슷한 규모의 전통목구조보다 약간 긴 편이며, 특히 후면 화방벽의 영향으로 2차모드에서 비틀림이 발생한 것으로 분석된다.

• 한국농공학회논문집
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• 제66권4호
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• pp.41-50
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• 2024

Precipitation is an important component of the hydrological cycle and a key input parameter for many applications in hydrology, climatology, meteorology, and weather forecasting research. Grid-based satellite rainfall products with wide spatial coverage and easy accessibility are well recognized as a supplement to ground-based observations for various hydrological applications. The error properties of satellite rainfall products vary as a function of rainfall intensity, climate region, altitude, and land surface conditions. Therefore, this study aims to evaluate the commonly used new global grid-based satellite rainfall product, Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS), using data collected at different spatial and temporal scales. Additionally, in this study, grid-based CHIRPS satellite precipitation data were used to evaluate the 2022 extreme drought. CHIRPS provides high-resolution precipitation data at 5 km and offers reliable global data through the correction of ground-based observations. A frequency analysis was performed to determine the precipitation deficit in 2022. As a result of comparing droughts in 2015, 2017, and 2022, it was found that May 2022 had a drought frequency of more than 500 years. The 1-month SPI in May 2022 indicated a severe drought with an average value of -1.8, while the 3-month SPI showed a moderate drought with an average value of 0.6. The extreme drought experienced in South Korea in 2022 was evident in the 1-month SPI. Both CHIRPS precipitation data and observations from weather stations depicted similar trends. Based on these results, it is concluded that CHIRPS can be used as fundamental data for drought evaluation and monitoring in unmeasured areas of precipitation.