• Korean Chemical Engineering Research
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• v.62 no.4
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• pp.327-334
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• 2024

The risks associated with coal dust explosion were investigated by analyzing various characteristics affecting the possibility of explosion. Samples were collected directly from two regions of the transfer process where the most explosions occurred in coal-fired power plants, and the composition ratio and average particle diameter that could affect the experiment were considered. As experimental items, explosion intensity, particle size and distribution, moisture content, dust concentration, minimum ignition energy, minimum ignition temperature, and oxygen concentration that affect the explosion were evaluated. As a result, the explosion intensity was found to have a maximum explosion pressure of 7.1 bar at a dust concentration of 500 g/m³ in sample A, and the maximum explosion pressure increase rate was 366 bar/s. In terms of dust particle diameter and particle size distribution, sample A had an average diameter of 35 ㎛ (D 50%), which was smaller than sample B. The moisture content was 5.7% in sample A, which was more than twice as high as 2.5% in sample B. The minimum explosion concentration was 400 g/m³ in sample A, which was lower than 2,000 g/m³ in sample B, so it had a risk. Since neither sample exploded at 1,000 mJ, it is judged that if the minimum energy is 500 mJ or higher, it can be regarded as dust with a low sensitivity to ignition compared to similar previous studies. The minimum ignition temperature was 532℃ in sample A and 634℃ in sample B, so sample A was more dangerous than sample B. The marginal oxygen concentration was 18.0% in both samples, so it is judged that there is a constant risk of explosion in the atmosphere.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.5
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• pp.951-958
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• 2024

The public is requesting to view and receive copies of local government CCTV footage in order to deal with unauthorized dumping, loss, and other inconveniences related to their lives, and to confirm whether an incident or accident has occurred. However, due to the difficulty of identification and the privacy of others in the video, local governments cannot provide the original CCTV footage to the public, so they provide the footage after manual masking. As a result, the public is demanding local governments to resolve distrust and dissatisfaction, and secondary users of video information, such as police, fire, and courts, are demanding quick and efficient ways to improve video utilization. In this paper, we study how to make local government CCTV video information available to the public. To this end, we de-personalize the entire video by mosaicking it into a certain size. We automate and simplify the process of viewing and creating replicas. We apply artificial intelligence pattern technology to design measures against video misuse. If the government reflects these results in its policies, the public's right-to-know needs will be met, public trusted in the government will increase, and the government's administrative efficiency will be improved.

• Journal of Food and Nutrition Research
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• v.10 no.3
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• pp.228-234
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• 2022

Korea has entered the aged society, with those aged over 65 years accounting for 14~20% of its population. Interest in the quality of life, nutrition, and health of the elderly is increasing. Since the energy intake of the elderly is lower than the estimated required amount, nutrient intake ratio of the elderly is related to mastication. Yanggaeng is a high-energy food made from agar, sugar, and red bean paste. Since it has a soft texture, it is highly utilized as a snack for the elderly who have inconvenience in mastication. Pinus koraiensis needle is known to possess antioxidant and antibacterial effects. The purpose of this study was to develop a functional snack added with Pinus koraiensis needle extract powder known to possess anti-inflammatory, anti-cancer, and antibacterial effects for the elderly that would be easy for them to chew. In this study, yanggaeng was manufactured with 0%, 2%, 4%, 6%, or 8% of Pinus koraiensis needle extract powder, white sediment, and agar. In the experiment, moisture contents, color values texture characteristics, antioxidant activities, and sensory preference results were evaluated. Moisture content was the highest in the group added 6% of the extract powder. It was the lowest in the group added 8% of the extract powder, showing a significant (p < 0.001) difference between the two. Hardness, cohesiveness, and springiness of texture characteristics were decreased significantly (p < 0.001) while the adhesiveness and chewiness of texture characteristics were increased significantly (p < 0.001) as the amount of addition increased. Regarding antioxidative activity measurements, levels of polyphenols were the highest (p < 0.001) in the group added with 8% of the extract powder. DPPH and ABTS radical scavenging activities were increased as the amount of addition increased (p < 0.001). Overall sensory preference was the highest for the 2% addition group. It decreased as the amount of addition increased (p < 0.001). Results of this study indicate that Pinus koraiensis needle extract powder with antioxidant and antibacterial effects can be used to manufacture yanggaeng to make functional snacks with improved quality characteristics for the elderly.

• Nutrition Research and Practice
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• v.18 no.5
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• pp.633-646
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• 2024

BACKGROUND/OBJECTIVES: Cladophora glomerata extract (CGE), rich in polyphenols, was reported to exhibit antidiabetic and renoprotective effects by modulating the functions of protein kinases-mediated organic anion transporter 1 (Oat1) and 3 (Oat3) in rats with type 2 diabetes mellitus (T2DM). Nevertheless, the antioxidant effects of CGE on such renoprotection have not been investigated. This study examined the mechanisms involved in the antioxidant effects of CGE on renal organic anion transport function in an in vivo study. MATERIALS/METHODS: Diabetes was induced in the rats through a high-fat diet combined with a single dose of 40 mg/kg body weight (BW) streptozotocin. Subsequently, normal-diet rats were supplemented with a vehicle or 1,000 mg/kg BW of CGE, while T2DM rats were supplemented with a vehicle, CGE, or 200 mg/kg BW of vitamin C for 12 weeks. The study evaluated the general characteristics of T2DM and renal oxidative stress markers. The renal organic transport function was assessed by measuring the para-aminohippurate (PAH) uptake using renal cortical slices and renal inflammatory cytokine expression in the normal diet (ND) and ND + CGE treated groups. RESULTS: CGE supplementation significantly reduced hyperglycemia, hypertriglyceridemia, insulin resistance, and renal lipid peroxidation in T2DM rats. This was accompanied by the normalization of high expressions of renal glutathione peroxidase and nuclear factor kappa B by CGE and vitamin C. The renal anti-inflammation of CGE was evidenced by the reduction of tumor necrosis factor-1α and interleukin-1β. CGE directly blunted sodium nitroprusside-induced renal oxidative/nitrosative stresses and mediated the PAH uptake in the normally treated CGE in rats was particularly noteworthy. These data also correlated with reduced nitric oxide production, highlighting the potential of CGE as a therapeutic agent for managing T2DM-related renal complications. CONCLUSION: These findings suggest that CGE has antidiabetic effects and directly prevents diabetic nephropathy through oxidative/nitrosative stress pathways.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.42 no.1
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• pp.22-34
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• 2024

The following are the results of this study, which examined changes in the size of the burial mounds of the 61 Joseon Dynasty royal tombs and the perception of the formative aesthetics of the burial mounds' elevations. First, the diameter of the burial mounds of the Joseon Dynasty royal tombs at the time of their construction was 7.08 to 10.78m. Among the three types of burial mounds, the formal burial mounds with a folding screen-like stonework were large, the burial mounds without stonework were mostly small, and the burial mounds with railing stone-like stonework varied in size. Second, the highly intensive management and repair activities from the Joseon Dynasty to today changed the size and shape of burial mounds. As a result, the size of the burial mounds is now 7.30 to 16.70m. Third, compared to the construction time, the diameters of most of the burial mounds with railing stone-like stonework and without stonework mostly increased. At the same time, there were cases where the diameter of the burial mounds with folding screen-like stonework decreased. Fourth, while the change in the height of the burial mounds with a folding screen-like stonework was small, that of the other two types was large, which is deemed to be in the same direction as the change in the burial mound diameter. Fifth, the perception of the ideal burial mound during the Joseon Dynasty was confirmed because the elevation of the burial mound described in 「Gaesu Dogam Uigwe (Renovation Office Protocol)」 is higher than the information recorded in numbers. Sixth, the Cultural Heritage Administration's managers chose more diverse burial mounds as ideal shapes than the expert group. The burial mounds most frequently selected by the Cultural Heritage Administration staff were lower in height than those selected by the expert group, showing a managerial tendency. In contrast, the expert group preferred the shape of the burial mounds with a high height and a rounded top.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.42 no.2
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• pp.1-11
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• 2024

This study aims to evaluate the repair status of stone structures, which are landscape heritage, focusing on cultural heritage repair norms. The study reviewed 296 repair reports published by the Cultural Heritage Administration and selected 8 cases of stone structure repairs. The repair status of these stone structures was evaluated based on three value attributes in the repair norms applied to cultural heritage both domestically and internationally: form and design, materials and quality, and tradition and technology. The results are as follows. First, in terms of form and design, changes were mainly focused on the foundation and backfill stones, which are non-visible structures, rather than the visible face stones. Second, in terms of materials and quality, there were numerous cases of inadequate verification and historical investigation. Despite significant differences in the strength and color of stones depending on their origin, which greatly impact the value attributes of the stone structures, the process of verifying the origin of replacement materials was omitted. Third, crucial elements such as tools, instruments, and techniques, which are vital for maintaining the value attributes of tradition and technology, were not recorded. Adherence to cultural heritage repair norms in the repair of stone structures was low. To enhance the repair quality of stone heritage, it is essential to strengthen compliance standards for maintaining the value attributes of non-visible structures, improve the historical investigation and verification of material origins, and establish detailed recording methods for the repair techniques and procedures used.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.42 no.1
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• pp.14-21
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• 2024

This research focuses on the restoration of stone structures situated within the landscaping facilities at royal palace and tomb heritages of the Joseon Dynasty, emphasizing their considerable importance in terms of scale and their contribution to the landscape's aesthetic form. The study conducts its analysis through the lens of three critical value attributes the form and design of the structures, the materials and textures used, and the traditional techniques employed. The subject of the study is the Gonshinji Pond, the pond and royal canal at Yeongneung and Nyeongneung, the royal canal at Gyeongbokgung Palace, and the flower steps at Yeongchunheon and Jipbokheon. Finding instances of stone wall repairs that complied with the established standards for cultural heritage repair proved challenging. Nonetheless, adherence to these norms and a methodical approach to deducing the original structure were evident in the most recent restoration cases. This discovery is likely to have considerable implications for the approach to future stone wall repair and restoration efforts. There's a clear need for the development of detailed guidelines and handbooks that thoroughly document the restoration process for stone walls, as outlined in repair reports.

• Nuclear Engineering and Technology
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• v.56 no.10
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• pp.4007-4017
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• 2024

In the city centre of Isparta, located in the southwestern part of Türkiye, indoor radon concentrations and gamma dose rate levels were observed above the world and country averages. For this reason, the determination of the natural radioactivity levels in soil samples of Isparta province is of great interest. In the present study, the activity concentrations of radionuclides (namely ²²⁶Ra,²³²Th, ⁴⁰K and ¹³⁷Cs) were investigated in the soil samples collected from 72 different points including the city centre and 12 towns of Isparta by using a gamma spectrometer with a high-purity germanium (HPGe) detector. The activity concentrations of ²²⁶Ra,²³²Th, ⁴⁰K and ¹³⁷Cs radionuclides in the samples were found in the range of 4.08 ± 0.39-69.84 ± 1.43 Bqkg^-1, 2.63 ± 0.28-65.66 ± 1.41 Bqkg^-1, 44.48 ± 3.17-452.38 ± 9.65 Bqkg^-1 and 0.28 ± 0.18-19.10 ± 0.61 Bqkg^-1 respectively. The averages of all the measurements were determined as 15.69 ± 0.72 Bqkg^-1 for 226Ra, 15.40 ± 0.78 Bqkg^-1 for ²³²Th, 210.60 ± 6.22 Bqkg^-1 for ⁴⁰K and 3.44 ± 0.31 Bqkg^-1 for ¹³⁷Cs. Although these values were below the country and world averages, it was revealed that the ²²⁶Ra and ²³²Th activity concentrations in the city centre exceeded the national and world averages. In addition, radiological risk maps of the analysed radionuclides were produced for the first time, covering all towns within the Isparta province. To evaluate the radiological hazards resulting from natural radionuclides, external hazard index (Hex), absorbed dose rate (D), annual effective dose equivalent (AEDE), male and female lifetime cancer risk (LCR) values were also calculated. The outcomes of this study revealed that all the radiological parameter averages for Isparta were lower than the world and country averages but the calculation results for the city centre displayed the opposite of this situation except for the external hazard index.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.5
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• pp.506-515
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• 2024

Owing to the interaction between a ship and the river bed, several phenomena resulting in increased resistance may have occurred. This increase in resistance is primarily due to the wave-making performance. Thus, this study aims to reduce the wave-making resistance by optimizing the performance of an electric canal cruise through changing the longitudinal center of gravity (LCG). Numerical simulations are performed to obtain the lowest resistance by optimizing the LCG position; subsequently, the ef ect of water depth is included as the next variable. Results show that LCG variations of 37.5%-52.5% Lpp can result in a wide range of total resistance. In deep water, a 72.67% resistance gap is achieved by comparing the highest and lowest resistances, whereas a slightly lower gap of up to 62.97% is achieved in shallow water. Additionally, smaller water depths correspond to higher resistance. The resistance increased by a maximum of 67.68% in shallow water measuring 1.5 m, as compared with the case of deep water. This increase in resistance is primarily due to wave-making resistance, which constitutes 84.99% of the total resistance.

• Journal of the Korean Society of Marine Environment & Safety
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• v.30 no.5
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• pp.415-425
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• 2024

The global maritime industry is developing rapidly owing to the emergence of autonomous ship technology, and interest in utilizing artificial intelligence derived from marine data is increasing. Among the diverse technological developments, ship-route clustering is emerging as an important technology for the commercialization of autonomous ships. Through route clustering, ship-route patterns are extracted from the sea to obtain the fastest and safest route and serve as a basis for the development of a collision-prevention system. High-quality, well-processed data are essential in ensuring the accuracy and efficiency of route-clustering algorithms. In this study, among the various route-clustering methods, we focus on the ship-route-similarity-based clustering method, which can accurately reflect the actual shape and characteristics of a route. To maximize the efficiency of this method, we attempt to formulate an optimal combination of data-preprocessing technologies. Specifically, we combine four methods of measuring similarity between ship routes and three dimensionality-reducing methods. We perform k-means cluster analysis for each combination and then quantitatively evaluate the results using the silhouette index to obtain the best-performing preprocessing combination. This study extends beyond merely identifying the optimal preprocessing technique and emphasizes the importance of extracting meaningful information from a wide range of ocean data. Additionally, this study can be used as a reference for effectively responding to the digital transformation of the maritime and shipping industry in the Fourth Industrial Revolution era.