• Fire Science and Engineering
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• v.18 no.1
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• pp.18-23
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• 2004

This paper describes the minimum ignition limits for propane-air 5.25 Vol.% mixture gases in low voltage inductive circiuts. The improved effects on the ignition limit are studied by parallel safety components(resistors) for propane-air 5.25 Vol.% mixture gas in low voltage inductive circuits. The experimental devices used in this test are the IEC type spark ignition test apparatus. The minimum ignition limits are controlled by the values of current in inductive circuit. Energy supplied from electric source is first accumulated at the inductance, it's extra energy is working as ignition source of the explosive gas. The improved effects on the ignition limit are respectively obtained as the maximum rising rate of 330% by composing parallel circuits between inductance and resistor as compared with disconnecting inductance with the safety components. The more values of inductance increase the higher improved effects of ignition limit rise. The less values of resistor the higher improved effects of ignition limit rise. It is considered that the result can be used for not only data for researches and development of intrinsically safe explosion-proof machines which are applied equipment and detectors used in dangerous areas but also for datum for its equipment tests.

• Journal of the Korea Society for Simulation
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• v.19 no.2
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• pp.99-106
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• 2010

In the anti-submarine warfare, a search using HMS is used as a basic strategy. The importance of HMS operation strategy is increasing, but it is hard to develop effective anti-submarine search strategy due to reciprocal actions among sea environments, search patterns, sonar operational tactics, anti-submarine search strategy, etc. In this research, a simulator was invented so as to analyze anti-submarine search patterns used when an HMS-carrying ship searches for submarine in various anti-submarine search environments. The simulator reflects various factors that influence anti-submarine search, and with consideration of search patterns of anti-submarine ships as well as evasive movement of submarines, it can simulate various anti-submarine search operations such as a collaborative anti-submarine operation by a single or multiple forces. Also, the simulator will contribute to developing and improving systematic and efficient HMS operational tactics in anti-submarine warfare.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.8
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• pp.2016-2029
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• 2023

Accurate prediction of critical illness is significant for ensuring the lives and health of patients. The selection of indicators affects the real-time capability and accuracy of the prediction for critical illness. However, the diversity and complexity of these indicators make it difficult to find potential connections between them and critical illnesses. For the first time, this study proposes an indicator analysis model to extract key indicators from the preoperative and intraoperative clinical indicators and laboratory results of critical illnesses. In this study, preoperative and intraoperative data of heart failure and respiratory failure are used to verify the model. The proposed model processes the datum and extracts key indicators through four parts. To test the effectiveness of the proposed model, the key indicators are used to predict the two critical illnesses. The classifiers used in the prediction are light gradient boosting machine (LightGBM) and eXtreme Gradient Boosting (XGBoost). The predictive performance using key indicators is better than that using all indicators. In the prediction of heart failure, LightGBM and XGBoost have sensitivities of 0.889 and 0.892, and specificities of 0.939 and 0.937, respectively. For respiratory failure, LightGBM and XGBoost have sensitivities of 0.709 and 0.689, and specificity of 0.936 and 0.940, respectively. The proposed model can effectively analyze the correlation between indicators and postoperative critical illness. The analytical results make it possible to find the key indicators for postoperative critical illnesses. This model is meaningful to assist doctors in extracting key indicators in time and improving the reliability and efficiency of prediction.

• Journal of Ecology and Environment
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• v.47 no.2
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• pp.49-62
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• 2023

Background: Over the past three decades, gradual eustatic sea-level rise has been considered a primary exogenous factor in the increased frequency of flooding and biological changes in several salt marshes. Under this paradigm, the potential importance of short-term events, such as ocean storminess, in coastal hydrology and ecology is underrepresented in the literature. In this study, a simulation was developed to evaluate the influence of wind waves driven by atmospheric oscillations on sedimentary and vegetation dynamics at the Skallingen salt marsh in southwestern Denmark. The model was built based on long-term data of mean sea level, sediment accretion, and plant species composition collected at the Skallingen salt marsh from 1933-2006. In the model, the submergence frequency (number yr^-1) was estimated as a combined function of wind-driven high water level (HWL) events (> 80 cm Danish Ordnance Datum) affected by the North Atlantic Oscillation (NAO) and changes in surface elevation (cm yr^-1). Vegetation dynamics were represented as transitions between successional stages controlled by flooding effects. Two types of simulations were performed: (1) baseline modeling, which assumed no effect of wind-driven sea-level change, and (2) experimental modeling, which considered both normal tidal activity and wind-driven sea-level change. Results: Experimental modeling successfully represented the patterns of vegetation change observed in the field. It realistically simulated a retarded or retrogressive successional state dominated by early- to mid-successional species, despite a continuous increase in surface elevation at Skallingen. This situation is believed to be caused by an increase in extreme HWL events that cannot occur without meteorological ocean storms. In contrast, baseline modeling showed progressive succession towards the predominance of late-successional species, which was not the then-current state in the marsh. Conclusions: These findings support the hypothesis that variations in the NAO index toward its positive phase have increased storminess and wind tides on the North Sea surface (especially since the 1980s). This led to an increased frequency and duration of submergence and delayed ecological succession. Researchers should therefore employ a multitemporal perspective, recognizing the importance of short-term sea-level changes nested within long-term gradual trends.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.4
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• pp.495-508
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• 2019

Tidal datums are key and basic information used in fields of navigation, coastal structures' design, maritime boundary delimitation and inundation warning. In Korea, the Approximate Lowest Low Water (ALLW) and the Approximate Highest High Water (AHHW) have been used as levels of tidal datums for depth, coastline and vertical clearances in hydrography and coastal engineering fields. However, recently the major maritime countries including USA, Australia and UK have adopted the Lowest Astronomical Tide (LAT) and the Highest Astronomical Tide (HAT) as the tidal datums. In this study, 1-hr interval 19-year sea level records (1999-2017) observed at 9 tidal observation stations along the west and south coasts of Korea were used to calculate LAT and HAT for each station using 1-minute interval 19-year tidal prediction data yielded through three tidal harmonic methods: 19 year vector average of tidal harmonic constants (Vector Average Method, VA), tidal harmonic analysis on 19 years of continuous data (19-year Method, 19Y) and tidal harmonic analysis on one year of data (1-year Method, 1Y). The calculated LAT and HAT values were quantitatively compared with the ALLW and AHHW values, respectively. The main causes of the difference between them were explored. In this study, we used the UTide, which is capable of conducting 19-year record tidal harmonic analysis and 19 year tidal prediction. Application of the three harmonic methods showed that there were relatively small differences (mostly less than ±1 cm) of the values of LAT and HAT calculated from the VA and 19Y methods, revealing that each method can be mutually and effectively used. In contrast, the standard deviations between LATs and HATs calculated from the 1Y and 19Y methods were 3~7 cm. The LAT (HAT) differences between the 1Y and 19Y methods range from -16.4 to 10.7 cm (-8.2 to 14.3 cm), which are relatively large compared to the LAT and HAT differences between the VA and 19Y methods. The LAT (HAT) values are, on average, 33.6 (46.2) cm lower (higher) than those of ALLW (AHHW) along the west and south coast of Korea. It was found that the S_a and N₂ tides significantly contribute to these differences. In the shallow water constituents dominated area, the M₄ and MS₄ tides also remarkably contribute to them. Differences between the LAT and the ALLW are larger than those between the HAT and the AHHW. The asymmetry occurs because the LAT and HAT are calculated from the amplitudes and phase-lags of 67 harmonic constituents whereas the ALLW and AHHW are based only on the amplitudes of the 4 major harmonic constituents.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.991-998
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• 2021

The purpose of this study is to investigate the image quality of the SE-EPI and SSH-TSE technique for MR DWI. Datum were analyzed for 35 PACS transmission datum(Normal part: 12 males, 13 females, Cerebral Infarction: 10(5males and 5females), and average age 68±7.32), randomly selected patients who underwent MRDWI tests. The equipment used was Ingenia CX 3.0T, SSH_TSE and SE-EPI pulse sequence and 32 Ch. head coil were used for data acquisition. Image evaluation was performed on the paired t-test and Wilcoxon tests, and was considered significant when the p value was 0.05 or less. As a result of quantitative analysis of SNR for DWI images, the mean and standard deviation values of 4 parts (WM, GM, BG, Cerebellum) in ADC (s/mm2), Diffusion b=0, 1000 images were higher in SE-EPI techniques(ADC: 120.50 ± 40, b=0: 54.50 ± 35.91, b=1000: 91.61 ± 36.63) than in SSH-TSE techniques(ADC: 99.69 ± 31.10, b=0: 43.52 ± 25.00 , b=1000: 60.74 ± 24.85)(p<0.05). The CNR values for GM-WM, BG-WM sites were also higher in SE-EPI technique (ADC: 116.08 ± 43.30, b=0:27.23 ± 09.10, b=1000: 78.50 ± 16.56) than in SSH-TSE(ADC: 101.08 ± 36.81, b=0: 23.96 ± 07.79 , b=1000: 74.30 ± 14.22). As a visual evaluation of observers, ghost artifact, magnetic susceptibility artifacts and overall image quality for SE-TSE and SSH-TSE all yielded high results from SSH-TSE techniques(ADC:3.6 ± 0.1, 2.8 ± 0.2, b=0: 4.3 ± 0.3, 3.4 ± 0.1 b=1000: 4.3 ± 0.2, 3.5 ± 0.2, p=0.000). In conclusion, the SE-EPI technique obtained an superiority in SNR and CNR measurements using SSH-TSE, SE-EPI. In the qualitative analysis, the SSH-TSE pulse sequence was obtained a high result according to the pulse sequence characteristics.

• Asian Oncology Nursing
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• v.1 no.1
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• pp.44-53
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• 2001

Despite the advances in cancer therapy in the last 20 years, cancer continues to be a life-threatening illness, and the newly diagnosed individual faces a crisis that emphasized his or her mortality. Patients who suffer from cancer may have psychological problems, especially depression. Most tend to seek the meaning of suffering when continuing pain was experienced. Then the search for meaning, which is one of the primary needs of humans, begins. This meaning is "unique and specific" to the individual, and it must be fulfilled by the individual alone. This study was conducted to provide a basis of data for a nursing intervention program to minimize a cancer patient's suffering and to understand the relationship between life satisfaction, depression, and the meaning of suffering in cancer patients. The sample was composed of 160 cancer patients who were inpatients or outpatients of three general hospitals in Seoul. Data collections were carried out from February 25th to April 20th of 2000. The data was analyzed using a SAS program for descriptive statistics, Pearson Correlations, ANOVA, and Duncan tests. The results were as follows: 1. The scores on the depression scale ranged from 20 to 65 with a mean of 40.76 (SD 9.6) The mean score on the suffering scale was 97.72 (SD 12.7), and the score of the life satisfaction ranged from 15 to 37 with a mean of 25.51 (SD 5.2). 2. There were significant correlations between the amount of life satisfaction and depression (r=-.61, P=.00), the life satisfaction and the meaning of suffering (r=.30, p=.00), and the depression and the meaning of suffering (r=-.24, p=.00). 3. The factors influencing the depression in patients with cancer are age (F=2.52, p=.04) and education level (F=3.98, p=.00). The level of the meaning of suffering in cancer patients differed by education level (F=4.13, p=.00). Also, the level of the life satisfaction in cancer patients differed by education level (F=2.72, p=.04). In conclusion, the correlation between the depression, the meaning of suffering, and life satisfaction can be used as a concrete and practical datum for the development of nursing intervention. This may assist patients with cancer, overcome their suffering and lead to a hopeful life by understanding the meaning of suffering.

• Journal of the Korean Society of Radiology
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• v.10 no.2
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• pp.73-79
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• 2016

The purpose of this analysis is to compare 2D T1 FEE and 3D T1 THRIVE for demonstration of the pancreas. A total of 85(45 men, 40 women; 58 years) PACS network datum were analysis clinically indicated pancreas MRI at 1.5 T. The SNRs and CNRs of 3D T1 THRIVE(SNR: $46.42{\pm}0.67$, CNR: $28.16{\pm}0.50$) showed significantly higher values than those from 2D T1 FEE(SNR: $53.84{\pm}1.20$, CNR: $35.48{\pm}0.70$), p<0.05, The image quality of the 3D T1 THRIVE($2.63 {\pm}0.14$) was significantly superior to that with the 2D T1 FEE($2.2{\pm}0.05$), but 3D T1 THRIVE revealed several artifacts resulting in poor quality. In conclusion, The 3D T1 THRIVE technique with a 1.5 T resulting in improved SNRs, CNRs and image quality was demonstrated.

• Journal of Acupuncture Research
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• v.29 no.6
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• pp.35-45
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• 2012

Objectives : This study was designed to investigate Effects of Sujeom powder(SJP) pharmacopuncture Injected at Jung-wan($CV_{12}$) in rats with caerulein-induced acute pancreatitis(AP). Methods : We examined changes of organ weight, histology, immunohistochemistry and gene expression of cycolooxygenase 2(COX-2) in the pancreas. Twenty adult male Sprague-Dawley rats were divided into four groups as follow: normal(Nor), caerulein-induced(Con), caerulein+SJP pharmacopuncture 0.2mL injected at Jung-wan($CV_{12}$)(SA), and caerulein+SJP pharmacopuncture 0.8 mL injected at Jung-wan($CV_{12}$)(SB) groups. Pancreatic tissues of rats from all groups were removed for histological observation and light microscopic examination. Interleukin-6(IL-6) levels were determined spectrophotometrically. Results : The ratio of pancreas/body weights was significantly(p<0.05) increased in the Con, the SA and the SB compared with the Nor, but was slightly decreased in the SA and in the SB groups compared with the Con. Caerulein administration has significantly(p<0.05) increased in the levels of amylase, but the SA, the SB significantly(p<0.05) decreased in the levels of these enzyme. The levels of amylase were increased significantly with caerulein administration, but were inhibited significantly in the SA and in the SB groups. Interleukin-6(IL-6) levels were significantly(p<005) increased in all groups compared with the Nor, especially in the SB. were significantly increased. The levels of Tumor necrosis factor(TNF)-${\alpha}$ levels were significantly increased in all groups compared with the Nor. In the conclusion, the datum of IL-6 and TNF-${\alpha}$ are suggested that the inflamation was still existed actively at a point of measurement(24 hours later). The COX-2 positive materials are observed in the pancreas from the Con, but these positive materials are decreased in the SJP pharmacopuncture at Jung-wan($CV_{12}$) treatment group. Conclusion : SJP pharmacopuncture injected at Jung-wan($CV_{12}$) is potentially capable of limiting pancreatic damage during AP by restoring the fine structure of acinar cells and tissues. Therefore we can say that SJP pharmacopuncture Injected at Jung-wan($CV_{12}$) may have beneficial effects in the treatment of caerulein-induded AP. Further studies about the adequate amount of the SJP pharmacopuncture and about more effective route of administration is still required.

• Journal of The Korean Association of Information Education
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• v.20 no.6
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• pp.655-672
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• 2016

The purpose of this study was to investigate the effects of prior-knowledge level and supportive information types in web-based learning using 4C/ID model(Four-Components Instructional Design model) on cognitive load and schema acquisition. To achieve the purpose, this study applied a web based learning. 166 university students participated in web-based learning for 4 weeks. After web-based learning, they checked self report for cognitive load and made concept map for schema acquisition and the datum from them were used for 2 ways ANOVA. According to the findings, groups in prior-knowledge level invested significantly differences on cognitive load and a question group in case of supportive information types didn't invested significant differences on cognitive load with statement group. Second, groups in prior-knowledge level invested significantly differences on schema acquisition and a question group in case of supportive information types invested significantly higher schema acquisition than a statement group. Furthermore, it happened interaction effect between supportive information types and prior-knowledge level on schema acquisition. This research has several implications with regard to suggesting the guidelines and conditions for the authentic task of the novice.