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        검색결과 1,076

        1.
        2024.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        흉골 자기공명영상 검사 시 호흡 등 환자 움직임에 의한 인공물 발생을 최소화하는 것은 어렵다. 하지만 자기공명영 상 검사는 타 영상 검사와 비교해 흉골 병변을 발견하는 데 있어 진단적 가치가 높은 장점이 있다. 따라서 본 연구에 서는 환자의 검사 자세 및 딥러닝 기법을 통해 최적의 검사 방법을 도출하고자 한다. 자세 별 영상 변화를 확인하기 위해 바로 누운 자세, 엎드린 자세, 유방 코일을 사용한 엎드린 자세로 진행하였으며, 고식적 기법의 영상과 Deep Resolve Boost(DRB) 기법을 적용한 영상을 비교 관찰하였다. 모든 대상에게 같은 조건으로 각 영상을 2회씩 획득 한 후 전반적인 영상 품질을 기준으로 정성적으로 평가하였고, DRB의 적용 여부에 따른 신호 대 잡음비의 변화 정도를 정량적으로 평가하여 개선 정도를 산출하였다. 정성적 평가에서 DRB 적용 여부와 무관하게 엎드린 자세, 유방 코일을 사용한 엎드린 자세, 바로 누운 자세 순으로 높은 점수를 얻었으며, DRB를 적용한 영상이 고식적 기법 의 영상보다 높은 점수를 얻었다. 또한 정량적 평가를 통해 유방 코일을 사용한 엎드린 자세, 엎드린 자세, 바로 누운 자세 순으로 높은 개선 정도를 확인하였다. 본 연구를 통해 흉골 검사 시 DRB 기법을 적용하는 것은 영상의 질을 높이는 방법임을 확인하였다. DRB를 적용하지 못하는 환경에서는 될 수 있으면 엎드린 자세를 적용하는 것을 권고하며, DRB를 적용할 수 있는 환경에서는 환자 측 인자를 고려하여 엎드린 자세와 유방 코일을 사용한 엎드린 자세를 모두 적용할 수 있다.
        4,000원
        3.
        2024.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study estimates the effects of traffic safety policies (e.g., the Minsik Act) on the seriousness of traffic accidents in children protection zones. METHODS : A difference-in-differences framework in which the change in the gap of seriousness of traffic accidents occurring in children protection zones and those occurring outside the zone before and after the implementation of the Minsik Act was applied. Furthermore, a placebo test, in which the samples are restricted to a specific period, is irrelevant to the time of students going to school. RESULTS : On average, when the factors causing traffic accidents are not controlled, the degree of damage in traffic accidents in children protection zones appears to be more serious The introduction of the Minsik Act has been shown to reduce the damage from traffic accidents in children protection zones. In particular, illegal U-turns and signal violations increased the severity of traffic accidents in children protection zones, and trucks caused the greatest damage. CONCLUSIONS : The traffic safety policy for children protection zones (Minsik Act) is effective in improving traffic safety by simply “strengthening legal regulations.” This strengthens the importance of traffic safety education to prevent drivers from engaging in driving behaviors such as illegal U-turns and traffic signal violations. It is necessary to ensure the traffic safety of children by establishing a truck operation policy that bypasses children protection zones.
        4,000원
        4.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study aimed to improve the effect of increasing the number of urban railway users when public transportation accessibility is improved by using village buses. METHODS : Using the case of Daejeon City, this study utilized the greenhouse gas reduction benefit among the benefits of the investment evaluation guidelines of the Ministry of Land, Infrastructure and Transport to demonstrate the effect of introducing village buses, a flexible means of transportation, to transportation-disadvantaged areas and improving accessibility, thereby inducing a change to urban railways. and were quantitatively analyzed. RESULTS : The number of users expected to switch to urban rail was 9,964 in 2020 and 9,220 in 2025. Thus, the greenhouse gas reduction effect is predicted to decrease annually by 34,554 t (2020) and 31,973 t (2025). CONCLUSIONS : Among the demand management techniques, reducing the use rate of passenger cars is one of the most important. For this policy, it is most effective to provide an alternative means of transportation.
        4,000원
        5.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The objective of this study was to review roadway management strategies that can be utilized in the event of a radiological emergency, select feasible alternatives, and simulate a portion of the West Coast network to analyze the effectiveness of these strategies. METHODS : The methodology of the study involved reviewing the relevant literature, extracting the implications, establishing an analysis procedure, and selecting an effectiveness evaluation scale. Using a national transportation database, a network was constructed using Toba, a macroscopic model. RESULTS : A reverse-flow lane system was applied to the West Coast Expressway Glory IC–Hampyeong IC (total 25 km), and a plan to increase the number of lanes was applied to the Seokgyo Street–Shinpyeong Intersection on National Route 23 (total extension 28 km). Consequently, both road management strategies were found to be effective. CONCLUSIONS : This study examined roadway management strategies that can be utilized in the event of a radiological emergency, selected feasible alternatives, and simulated a portion of the West Coast network to verify the effectiveness of these strategies. In the case of reverse flow lanes, it is most effective when applied to expressways that can restrict the entrance and exit of vehicles. In the case of increasing the number of lanes, it is most effective when applied to general roads, and institutional arrangements should be made to enable two-way traffic to use the reserved shoulder lanes.
        4,000원
        6.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        UV and O3 are materials used in the water treatment process, and many studies have been reported to remove organic matters, contaminants, and microorganisms. In this study, we were investigated effects of Chirnomidae (Chironomus flaviplumus, Chironomus riparius), which are contamination indicator species to exposure UV and O3 for the survival rate, body color change and gene expression response. The survival rate of C. flaviplumus exposed to UV decreased to about 70% after 24 hours, and C. riparius about 50%. There was no change in the survival rate of C. flaviplumus exposed to O3, and C. riparius decreased to 95% after 10 minutes of exposure, but there was no change during the subsequent exposure time. In addition, UV and O3 exposure to the two species in body color faded in a time-dependent. In the HSP70 gene expression, C. riparius showed an increase in expression after UV exposure compared to the control group, and a significant difference was shown 12 hours after exposure (P<0.05). C. flaviplumus exposed to O3 showed a relatively low expression compared to the control group, and showed a significant difference at 10 minutes and 1 hour after exposure (P<0.05). These results reported the ecotoxicological effects on Chironomidae according to UV and O3 exposure. Therefore, the results of this study can be used as basic data to understand the effects of UV and O3, which are disinfectants used in water treatment plants, on Chirnomidae entering plants. Key words: Chironomus flaviplumus, Chironomus riparius, UV, O3, acute toxicity, survival
        4,000원
        7.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Cadmium (Cd), a heavy metal found in the aquatic environment, accumulates in organisms through the food chain. In the study, we investigated the survival rates, measurement of body Cd levels, and expression analysis of the stress response genes (Heat shock protein 70: HSP70 and Heat shock protein 60: HSP60) and antioxidant enzyme Glutathione S-Transferases (GST) on benthic oligochaete worm Tubifex tubifex exposed three concentrations of Cd, to analyze the bioaccumulation and changes of stress gene expressions to exposure toxicity of the Cd-spiked sediment. Survival rates of T. tubifex exposed to the Cdspiked sediment were 93% at 0.4 mg kg-1 Cd, 96% at 1.87 mg kg-1 Cd, and 93% at 6.09 mg kg-1 Cd for 10 days. Cd concentration in the body of T. tubifex was higher than that in the sediment. After Cd exposures for 10 days, the body Cd levels were 18.4 mg kg-1, 13.06 mg kg-1, and 79.11 mg kg-1 at exposed three concentrations of Cd, respectively. Upregulation of HSP70 gene expression was observed at all concentrations of exposed Cd as a time-dependent manner, whereas transcriptional expression of the HSP60 gene increased as a timedependent manner in T. tubifex exposed to the relative high concentration (6.09 mg kg-1) of Cd. However, GST gene expression increased on day 1 at all concentrations after Cd exposures, and then downregulated until 10 days. These results indicate to ecotoxicological and molecular effects in benthic oligochaete worm T. tubifex to Cd-spiked sediment and provide the basic information for the utilization of environmental toxicity assessment using the T. tubifex as a aquatic pollution indicator species.
        4,000원
        8.
        2023.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to develop a nursing education program using Web-based simulation for the care of patients with intracranial pressure. An additional aim was to verify the effectiveness of nursing knowledge, problem-solving competency, a critical thinking disposition, and the expectation of learning transfer. Methods: This was an experimental study using repeated measures with a nonequivalent control group. The participants were senior nursing students, randomly assigned to experimental (n=30) and control (n=30) groups. The experimental group participated in a nursing education program that included Web-based lectures, pre-briefing, Web-based simulation, and debriefing, whereas the control group’s program included only Web-based lectures. Results: A significant difference was found between the experimental and control groups in problem-solving competency (F=5.84, p=.005), critical thinking disposition (F=4.25, p=.021), and the expectation of learning transfer (t=2.30, p<.025). Also, a significant interaction between time and group was found in problem-solving competency and critical thinking disposition. Conclusion: The results of this study showed that the education program using Web-based simulation positively affected nursing students’ problem-solving competency, critical thinking disposition, and the expectation of learning transfer. Therefore, this program can be considered a valuable aid in educating nursing students.
        4,800원
        12.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 수염에 대한 호감도 측정을 위해 선호 및 비선호 선택지와 함께 호감/비호감 사유 판단 문항 및 인구통계학적 특성 문항을 제시한 설문지의 최종 응답 300부를 표본으로 하여 인구통계학적 특성을 알기 위하여 빈도분석을 하였고, 선호도의 차이를 분석하기 위하여 Cross-Tab(교차분석) 분석을 거쳐 T-test와 일원 분산분석을 하였다. 연구 결과, 남성의 수염 조형별 선호도 및 비 선호도에는 차이가 있었으며, 그 차이 수준은 남녀 집단 및 연령대 집단 간에 통계적 유의성을 보였다. 추가로, 각 집단 범주마 다 수염 조형별 호감/비호감 판단 사유에서도 차이를 보이는 것으로 나타났다. 또한, 남성의 수염 조형에 따른 선호도와 비 선호도는 차이가 있으며, 그 판단 근거인 호감도와 비호감도의 주된 이유에서도 지각자 특성별로 다양한 차이가 있음을 확인하였다. 이러한 결과를 통해 이용 및 미용 학문 연구에 시사점을 제시 하였다.
        4,600원
        13.
        2023.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study establishes a methodology for evaluating traffic safety in response to the introduction of one-way traffic using surrogate safety measures and analyzes the impact of one-way traffic safety through a case analysis. METHODS : The SSAM(Surrogate Safety Assessment Measure) was used to analyze traffic conflicts (TTC(Time to Collision) and PET(Post Encroachment Time)), which are safety indicators. The SSAM input variable dataset was constructed using a VISSIM(Verkehr In Städten - SIMulationsmodell) simulation. RESULTS : Introducing one-way traffic rather than the pending issue (two-way operation) improved traffic safety as the possibility of TTC or PET was reduced. In addition, the analysis results showed that the average TTC time and average PET time increased with the introduction of the one-way system. It is anticipated that the avoidance action time taken by the driver to avoid dangerous situations will also increase, which will help improve traffic safety. CONCLUSIONS : As an alternative to solving traffic safety and communication problems occurring at the study site, it was determined that a one-way system would be effective. Furthermore, a one-way system that allows two-lane roads on both sides to move one-way and allows parking in pockets on both sides of the road would be appropriate.
        4,000원
        15.
        2023.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : This study empirically analyzes the determinants of fatal accidents based on raw data on traffic accidents occurring in Chungnam in 2020. METHODS : Regression models based on theoretical arguments for fatal traffic accidents are estimated using a binomial logit model. RESULTS : The prediction model for fatal accidents is affected by the degree of urbanization of the region, month and day of the accident, type of accident, and type of law violation. In addition, speeding or illegal U-turns among law violations appear more likely to result in fatal accidents. The road surface conditions at the time of the accident do not show a significant difference in the probability of fatality among traffic accidents. However, the probability of a fatal accident is rather lower in case of a snowy road; this is plausible, as drivers tend to drive more carefully in bad weather conditions. CONCLUSIONS : Among traffic accidents, fatal accidents appear to be affected by the time and place of the accident, type of accident, and weather conditions at the time of the accident. These analysis results suggest policy implications for reducing fatal accidents and can be used as a basis for establishing related policies.
        4,000원
        17.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        As the demand for aesthetic orthodontic treatment increases, the use of self-ligating ceramic brackets is increasing. For stable treatment, there should be no fracture or deformation of the self-ligation ceramic bracket door. Therefore, considering the situation in which labial displacement of teeth occurs in the orthodontic treatment stage. For this study, a model of the mandibular anterior region of a ceramic self-ligating bracket with a passive sliding door mechanism was selected. The measured tensile force data was substituted into the simulation analysis conditions, and the tensile force, stress distribution, and deformation values were analyzed using the finite element method. Using this, it is able to use the design elements of the orthodontic bracket that should be considered as design inputs in the development stage.
        4,000원
        18.
        2023.01 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Roses are one of the most produced flower species in the world, and cut roses are produced in the greenhouses all year round. Recently, due to the increase in the temperature in the greenhouses in summer, the quality of cut roses is seriously deteriorated, such as shortening the stem length. This study was conducted to investigate the effects of the growing seasons on the qualities of cut roses and also to test the effect of cooling at night in high temperature season on the cut flower qualities of roses. Comparing the qualities and yields of cut roses for each season, the major cut flower qualities such as flower stem length, stem diameter and fresh weight were statistically significantly decreased in roses (‘Pink Beauty’ and ‘Pink Shine’) produced in summer. The yields didn’t show a statistically significant difference in both cultivars. Investigating the cut flower qualities, the flower stem length increased by 15% for ‘Pink Beauty’, 11% for ‘Ararat’, and 12% for ‘Pink Shine’ when treated with cooling at night in warm season than the untreated control. In addition, when treated with cooling at night in warm season, the fresh weight of all three cultivars increased by 20-30% statistically significantly than conventionally cultivated control. It is expected that cooling at night in warm season will be helpful to improve the cut flower quality deterioration in summer.
        4,000원
        19.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Gut contents analysis is essential to predict the impact of organisms on food source changes due to variations of the habitat environment. Previous studies of gut content analysis have been conducted using traditional methods, such as visual observation. However, these studies are limited in analyzing food sources because of the digestive process in gut organ. DNA metabarcoding analysis is a useful method to analyze food sources by supplementing these limitations. We sampled marine fish of Pennahia argentata, Larimichthys polyactis, Crangon affinis, Loligo beka and Sepia officinalis from Gwangyang Bay and Yeosu fisheries market for analyzing gut contents by applying DNA metabarcoding analysis. 18S rRNA v9 primer was used for analyzing food source by DNA metabarcoding. Network and two-way clustering analyses characterized the relationship between organisms and food sources. As a result of comparing metabarcoding of gut contents for P. argentata between sampled from Gwangyang Bay and the fisheries market, fish and Copepoda were analyzed as common food sources. In addition, Decapoda and Copepoda were analyzed as common food sources for L. polyactis and C. affinis, respectively. Copepoda was analyzed as the primary food source for L. beka and S. officinalis. These study results demonstrated that gut contents analysis using DNA metabarcoding reflects diverse and detailed information of biological food sources in the aquatic environment. In addition, it will be possible to provide biological information in the gut to identify key food sources by applying it to the research on the food web in the ecosystem.
        4,000원
        20.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Recently, with the development of genetic technology, interest in environmental DNA (eDNA) to study biodiversity according to molecular biological approaches is increasing. Environmental DNA has many advantages over traditional research methods for biological communities distributed in the environment but highly depends on the established base sequence database. This study conducted a comprehensive analysis of the habitat status and classification at the genus level, which is mainly used in eDNA (12S rRNA, 16S rRNA, 18S rRNA, COI, and CYTB), focusing on Korean registration taxon groups (phytoplankton, zooplankton, macroinvertebrates, and fish). As a result, phytoplankton and zooplankton showed the highest taxa proportion in 18S rRNA, and macroinvertebrates observed the highest ratio in the nucleotide sequence database in COI. In fish, all genes except 18S rRNA showed a high taxon ratio. Based on the Korean registration taxon group, the gene construction of the top 20 genera according to bio density observed that most of the phytoplankton were registered in 18S rRNA, and the most significant number of COI nucleotide sequences were established in macroinvertebrates. In addition, it was confirmed that there is a nucleotide sequence for the top 20 genera in 12S rRNA, 16S rRNA, and CYTB in fish. These results provided comprehensive information on the genes suitable for eDNA research for each taxon group.
        4,000원
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