• 수산해양기술연구
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• 제59권3호
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• pp.261-263
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• 2023

Recently, universities of fisheries and institutions related to fisheries are actively carrying out a project to build new fisheries training ships. These new fisheries training ships are significantly larger in size and longer in length than the previous ships. In addition, these new ships basically have space that can accommodate more than 100 crew and passenger. On the other hand, they are excluded from IMO maneuverability evaluation since the size of these ships are still less than 100 m in length (LBP). These results have had an impact on the study of maneuverability of fishing vessels including the fisheries training ships. Against these backgrounds, the authors conducted a study to estimate the maneuvering characteristics of fisheries training ship Baek-Kyung according to depth in order to prepare a maneuvering characteristic index that enables the large fisheries training ships to navigate more safely using a modified empirical formula. It was confirmed that the maneuvering characteristics of Baek-Kyung changed significantly as the values of the hydrodynamic force coefficients changed as the water depth gradually decreased from around 1.5 (approx. 8 m in depth) of the ratio of the water depth to the ship draft. The results of this study will not only help navigators understand the maneuvering characteristics of Baek-Kyung, but also serve as an indicator when navigating in shallow water. In addition, the accumulation of these results will serve as a basis for future study on maneuverability of fishing vessel types.

• 정보보호학회논문지
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• 제33권4호
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• pp.687-697
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• 2023

공격 양상이 더욱 지능화되고 다양해진 봇넷은 오늘날 가장 심각한 사이버 보안 위협 중 하나로 인식된다. 본 논문은 UGR과 CTU-13 데이터 셋을 대상으로 반지도 학습 딥러닝 모델인 오토엔코더를 활용한 봇넷 검출 실험결과를 재검토한다. 오토엔코더의 입력벡터를 준비하기 위해, 발신지 IP 주소를 기준으로 넷플로우 레코드를 슬라이딩 윈도우 기반으로 그룹화하고 이들을 중첩하여 트래픽 속성을 추출한 데이터 포인트를 생성하였다. 특히, 본 논문에서는 동일한 흐름-차수(flow-degree)를 가진 데이터 포인트 수가 이들 데이터 포인트에 중첩된 넷플로우 레코드 수에 비례하는 멱법칙(power-law) 특징을 발견하고 실제 데이터 셋을 대상으로 97% 이상의 상관계수를 제공하는 것으로 조사되었다. 또한 이러한 멱법칙 성질은 오토엔코더의 학습에 중요한 영향을 미치고 결과적으로 봇넷 검출 성능에 영향을 주게 된다. 한편 수신자조작특성(ROC)의 곡선아래면적(AUC) 값을 사용해 오토엔코더의 성능을 검증하였다.

• 여성건강간호학회지
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• 제28권4호
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• pp.296-306
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• 2022

Purpose: This study investigated the effects of peripheral neuropathy symptoms, self-care ability, and disturbances to daily life on quality of life (QoL) among gynecological cancer patients undergoing chemotherapy. Methods: The participants included 144 patients with gynecological cancer undergoing anticancer chemotherapy at a tertiary hospital in Seoul, South Korea, from December 1, 2021 to January 28, 2022. Convenience sampling was used to recruit patients who had received 4 or more cycles of chemotherapy using a paclitaxel-platinum regimen, and a self-reported questionnaire was used to collect data. Descriptive statistics, the t-test, analysis of variance, Scheffé test, Pearson correlation coefficients, and multiple regression analysis were performed. Results: Most of the participants had ovarian cancer (70.1%) or endometrial cancer (14.6%), and the most common number of treatment cycles was 6 to 10 (29.2%). The mean QoL (60.83±19.89) was greater than the midpoint. The regression model analyzing the patients' QoL was statistically significant (F=15.38, p<.001) with an explanatory power of 56.7%. Self-care ability (β=.39, p<.001), disturbances to daily life (β=-.38, p<.001), the duration of peripheral neuropathy symptoms (β=2.14, p=.034), and regular exercise (β=-2.12, p=.036) were found to significantly affect QoL. Conclusion: Efforts to improve the self-care ability of gynecological cancer patients who have experienced peripheral neuropathy after receiving chemotherapy and mitigate disturbances to their daily life can improve their QoL. Healthcare professionals should identify peripheral neuropathy symptoms and examine the effects of the symptoms on patients' daily lives. Improving the self-care ability of patients and alleviating their limitations in daily life may improve QoL.

• 여성건강간호학회지
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• 제29권1호
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• pp.44-54
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• 2023

Purpose: Uncertainty and restrictions on daily life have increased fear, stress, and depression during the coronavirus disease 2019 (COVID-19) pandemic. Depression is the most common mental health problem in pregnant women. The purpose of this study was to evaluate the levels of fear and stress related to COVID-19 experienced by pregnant women, as well as their levels of depression, and to examine the factors associated with depression during pregnancy. Methods: This was a cross-sectional, correlational study conducted among 153 pregnant women who visited a maternity hospital in Busan, South Korea. A self-reported questionnaire was used for data collection from December 18, 2021 to March 8, 2022. Data were analyzed using descriptive statistics, the independent t-test, one-way analysis of variance, Pearson correlation coefficients, and multiple regression. Results: Pregnant women experienced a moderate level of fear related to COVID-19, with an average score of 21.55±4.90. The average score for depression during pregnancy was 14.86±11.10, with 50.3% of the participants experiencing depression (≥13). The factors associated with depression during pregnancy were fear of COVID-19, contact with a confirmed case of COVID-19, being in the third trimester of pregnancy, high stress levels due to difficulties experienced from social distancing measures, and unintended pregnancy. These five statistically significant factors explained 35.0% of variance in depression during pregnancy. Conclusion: Considering the prevalence of depression in pregnant women during the COVID-19 pandemic, it is necessary to develop interventions to reduce anxiety by providing correct information and alleviating the stress of social distancing.

• 무역학회지
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• 제43권3호
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• pp.219-243
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• 2018

본 연구는 가파르게 성장하고 있는 대(對)중국 역직구시장에 주목하였다. 이를 위해 중국소비자들을 대상으로 국내의 역직구사이트에 대한 평가모델을 수립하였으며, 소비자들의 특성 별로 차이 검정을 실시하여 세분 시장 별로 구체적인 전략적 대안을 제시하고자 하였다. 연구결과 사이트 이용에 대한 우려 수준이 확신 수준 보다 향후 소비행동인 지속적 이용행동에 강력한 파급효과가 있음을 실증하였다. 또한 사이트 이용에 대한 확신과 우려 수준에 영향을 미치는 선행요인 가운데에는 기존의 연구들에서 논의 되어온 혜택지각요인, 위험지각요인 뿐 만 아니라 사회문화적 영향요인 또한 유의미한 영향을 미친다는 것을 확인하였다. 아울러 본 연구는 이용자들의 관여수준에 따라 역직구사이트에 대한 평가를 비교해 봄으로써 경로간의 차이를 분석하여 집단 별로 요구되는 실무적 시사점들을 제시하고자 하였다.

• 치위생과학회지
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• 제23권4호
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• pp.330-342
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• 2023

Background: As the medical knowledge base grows at an accelerating rate, evidence-based clinical performance becomes increasingly important for providing quality care. Previous studies have highlighted the need to promote job crafting to actualize evidence-based practical skills in the medical field. This study aimed to investigate the degree of evidence-based practice among dental hygienists and assess the impact of job crafting on the evidence-based practical skills of dental hygienists. Methods: Dental hygienists working at dental hospitals and clinics in Seoul and Gyeonggi Province were surveyed between February 28 and April 6, 2023. The sample was comprised of 267 participants. The hypotheses were tested independent t-tests, one-way analysis of variance, Pearson's correlation coefficients, and multiple regression analyses using SPSS 29.0. Results: The degree of job crafting by dental hygienists demonstrated significant differences based on educational attainment, workplace size, and workplace type. Evidence-based practical skills exhibited significant variations based on educational attainment and job position. All job crafting subfactors demonstrated positive correlations with evidence-based practical skills. The job crafting subfactors affecting the evidence-based practical skills of dental hygienists were 'increasing structural job resources' and 'increasing challenging job demands,' which together explained 38.7% of the variance in evidence-based practical skills. Conclusion: This study demonstrates that job crafting was positively and significantly correlated with evidence-based practical skills. To strengthen the job crafting ability of dental hygienists, improving environmental conditions and fostering an organizational culture that motivates continued participation in education is necessary. The development and promotion of programs that enable learning of the latest evidence should be actively pursued. Additionally, regular attendance at workshops and participation in organizational evidence-based practice education programs are necessary.

• 한국환경보건학회지
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• 제49권6호
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• pp.353-361
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• 2023

Background: Noise has been linked to an increased risk of various health issues, including stress, anxiety, insomnia, and cardiovascular disorders. However, research on the relationship between residential traffic noise and mental health in South Korea is limited. Objectives: This study aims to examine the correlation between regional traffic noise levels and mental health using an ecological study design. Methods: In this ecological study, all data were collected from the Korean Statistical Information Service. Traffic noise data in residential areas and the prevalence of mental health indices in 44 cities with noise monitoring stations were obtained. Pearson correlation coefficients were calculated to assess the relationship between regional traffic noise levels and mental health indices. Results: Daytime traffic noise levels were found to have a positive correlation with stress perception (r=0.428, p=0.004) and showed a borderline positive correlation with depressive symptom prevalence (r=0.273, p=0.073). In cities with airports, significant correlations was observed between 24-hour average noise levels and depressive symptoms (r=0.604, p=0.010), whereas this relationship was not observed in cities without airports (r=0.048, p=0.813). Multiple regression analysis, which adjusted for factors such as age, gender ratio, smoking, obesity, unemployment, urban size, and the presence of an airport, confirmed the relationship between 24-hour average noise levels and stress perception (beta=0.287, p=0.024). Conclusions: This study identified correlations between regional traffic noise levels and depressive symptoms or stress perception in adults, with a more pronounced effect in areas with airports. These findings suggest a potential impact of residential traffic noise on mental health, highlighting the importance of preventive measures like noise management in urban planning to promote mental well-being.

• 한국항행학회논문지
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• 제27권6호
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• pp.841-848
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• 2023

위성 항법 장치 (GPS; global positioning system) 항법메시지에 포함된 Klobuchar 전리층모델은 L1 단주파수 사용자들에게 전리층 보정정보를 제공한다. 전리층모델 정확도는 항법해의 정확도에 큰영향을 끼치므로 이에 관한 분석이 필요하다. 본 연구에서는 1993년부터 2022년까지의 GPS 항법메시지를 조사하여 Klobuchar 모델의정확도 및 계수 존재 여부와 효용성 여부를 분석 하였다. 초기 GPS 항법메시지의 경우 전리층데이터를 포함하지 않는 경우가 많으며, 전리층모델을 포함되어 있더라도 정확도가 상당히 낮은 경우가 많이 존재하였다. 전리층모델의 정확도가 안정화된 2002년부터 2022년까지 전리층모델의 정확도 변화와 지자기 위도에 따른 정확도 차이를 IGS (International GNSS Service)에서 제공하는 전리층모델과 비교하는 방법으로 분석하였다.

• Korean Journal of Radiology
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• 제20권4호
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• pp.558-568
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• 2019

Objective: To evaluate whether computed tomography (CT) reconstruction algorithms affect the CT texture features of the liver parenchyma. Materials and Methods: This retrospective study comprised 58 patients (normal liver, n = 34; chronic liver disease [CLD], n = 24) who underwent liver CT scans using a single CT scanner. All CT images were reconstructed using filtered back projection (FBP), hybrid iterative reconstruction (IR) (iDOSE⁴), and model-based IR (IMR). On arterial phase (AP) and portal venous phase (PVP) CT imaging, quantitative texture analysis of the liver parenchyma using a single-slice region of interest was performed at the level of the hepatic hilum using a filtration-histogram statistic-based method with different filter values. Texture features were compared among the three reconstruction methods and between normal livers and those from CLD patients. Additionally, we evaluated the inter- and intra-observer reliability of the CT texture analysis by calculating intraclass correlation coefficients (ICCs). Results: IR techniques affect various CT texture features of the liver parenchyma. In particular, model-based IR frequently showed significant differences compared to FBP or hybrid IR on both AP and PVP CT imaging. Significant variation in entropy was observed between the three reconstruction algorithms on PVP imaging (p < 0.05). Comparison between normal livers and those from CLD patients revealed that AP images depend more strongly on the reconstruction method used than PVP images. For both inter- and intra-observer reliability, ICCs were acceptable (> 0.75) for CT imaging without filtration. Conclusion: CT texture features of the liver parenchyma evaluated using the filtration-histogram method were significantly affected by the CT reconstruction algorithm used.

• 상하수도학회지
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• 제37권6호
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• pp.363-373
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• 2023

Numerous studies have established a correlation between sociodemographic characteristics and water usage, identifying population as a primary independent variable in mid- to long-term demand forecasting. Recent dramatic sociodemographic changes, including urban concentration-rural depopulation, low birth rates-aging population, and the rise in single-person households, are expected to impact water demand and supply patterns. This underscores the necessity for operational and managerial changes in existing water supply systems. While sociodemographic characteristics are regularly surveyed, the conducted surveys use aggregate units that do not align with the actual system. Consequently, many water demand forecasts have been conducted at the administrative district level without adequately considering the water supply system. This study presents an upward water demand forecasting model that accurately reflects real water facilities and consumers. The model comprises three key steps. Firstly, Statistics Korea's SGIS (Statistical Geological Information System) data was reorganized at the DMA level. Secondly, DMAs were classified using the SOM (Self-Organizing Map) algorithm to consider differences in water facilities and consumer characteristics. Lastly, water demand forecasting employed the PCR (Principal Component Regression) method to address multicollinearity and overfitting issues. The performance evaluation of this model was conducted for DMAs classified as rural areas due to the insufficient number of DMAs. The estimation results indicate that the correlation coefficients exceeded 0.9, and the MAPE remained within approximately 10% for the test dataset. This method is expected to be useful for reorganization plans, such as the expansion and contraction of existing facilities.