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A Study on the Analysis of Chemical Leakage Accidents Using CFD Simulation (CFD 시뮬레이션을 활용한 화학물질 누출사고 분석에 관한 연구)

  • Su-Bin An;Chang-Bong Jang;Kyung-Su Lee;Hye-Ok Kwon
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.33 no.3
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    • pp.346-354
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    • 2023
  • Objectives: Chemical accidents cause extensive human and environmental damage. Therefore, it is important to prepare measures to prevent their recurrence and minimize future damage through accident investigation. To this end, it is necessary to identify the accident occurrence process and analyze the extent of damage. In this study, the development process and damage range of actual chemical leakage accidents were analyzed using CFD. Methods: For application to actual chemical leakage accidents using FLACS codes specialized for chemical dispersion simulation among CFD codes, release rate calculation and 3D geometry were created, and scenarios for simulation were derived. Results: The development process of the accident and the dispersion behavior of materials were analyzed considering the influencing factors at the time of the accident. In addition, to confirm the validity of the results, we compared the results of the actual damage impact investigation and the simulation analysis results. As a result, both showed similar damage impact ranges. Conclusions: The FLACS code allows the detailed analysis of the simulated dispersion process and concentration of substances similar to real ones. Therefore, it is judged that the analysis method using CFD simulation can be usefully applied as a chemical accident investigation technique.

Real-World Compliance of Surgical Treatment According to the Korean Gastric Cancer Guideline 2018: Evaluation From the Nationwide Survey Data 2019 in Korea

  • Sang Soo Eom;Sin Hye Park;Bang Wool Eom;Hong Man Yoon;Young-Woo Kim;Keun Won Ryu
    • Journal of Gastric Cancer
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    • v.23 no.4
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    • pp.535-548
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    • 2023
  • Purpose: This study evaluated real-world compliance with surgical treatment according to Korea's gastric cancer treatment guidelines. Materials and Methods: The 2018 Korean Gastric Cancer Treatment Guidelines were evaluated using the 2019 national survey data for surgically treated gastric cancer based on postoperative pathological results in Korea. In addition, the changes in surgical treatments in 2019 were compared with those in the 2014 national survey data implemented before the publication of the guidelines in 2018. The compliance rate was evaluated according to the algorithm recommended in the 2018 Korean guidelines. Results: The overall compliance rates in 2019 were 83% for gastric resection extent, 87% for lymph node dissection, 100% for surgical approach, and 83% for adjuvant chemotherapy, similar to 2014. Among patients with pathologic stages IB, II, and III disease who underwent total gastrectomy, the incidence of splenectomy was 8.08%, a practice not recommended by the guidelines. The survey findings revealed that 48.66% of the patients who underwent gastrectomy had pathological stage IV disease, which was not recommended by the 2019 guidelines. Compared to that in 2014, the rate of gastrectomy in stage IV patients was 54.53% in 2014. Compliance rates were similar across all regions of Korea, except for gastrectomy in patients with stage IV disease. Conclusions: Real-world compliance with gastric cancer treatment guidelines was relatively high in Korea.

Pomegranate extract on eroded dentin: antioxidant action, bond strength and morphology of the adhesive interface after aging

  • Thiago Vinicius Cortez;Nathalia Mancioppi Cerqueira;Julia Adornes Gallas;Wanderley Pereira Oliveira;Silmara Aparecida Milori Corona;Aline Evangelista Souza-Gabriel
    • Restorative Dentistry and Endodontics
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    • v.49 no.1
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    • pp.9.1-9.14
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    • 2024
  • Objectives: This study aimed to evaluate the effect of pomegranate solution (Punica granatum) on eroded dentin through antioxidant action, shear bond strength (SBS) and interface morphology. Materials and Methods: The 10% pomegranate peel extract was prepared by the lyophilization method. Punicalagin polyphenol was confirmed by high-performance liquid chromatography. Antioxidant activity was evaluated by capturing the 2,2-diphenyl1-picrylhydrazyl (DPPH) radical. For the SBS, 48 dentin fragments were divided into sound or eroded, and subdivided according to the pretreatment (n = 12): water or P. granatum. The surfaces were restored with self-etch adhesive and a bulk-fill resin (Ecosite; DMG). The SBS was done immediately (24 hours) and after thermal cycling + water storage (12 months). For scanning electron microscopy, 48 dentin fragments (24 sound and 24 eroded) received the same treatments as for SBS (n = 6), and they were analyzed after 24 hours and 12 months. Results: The P. granatum had antioxidant action similar (p = 0.246) to the phenolic standard antioxidants. After 24 hours, eroded dentin had lower SBS than sound dentin (p < 0.001), regardless of the pretreatment. After 12 months, P. granatum maintained the SBS of sound dentin (13.46 ± 3.42 MPa) and eroded dentin (10.96 ± 1.90 MPa) statistically similar. The lowest values were found on eroded dentin treated with water (5.75 ± 1.65 MPa) (p < 0.001). P. granatum on eroded dentin caused peritubular demineralization and hybrid layer with resin tags. Conclusions: The pomegranate extract had antioxidant action and preserved the adhesive interface of the eroded dentin.

Effects of Expert-Determined Reference Standards in Evaluating the Diagnostic Performance of a Deep Learning Model: A Malignant Lung Nodule Detection Task on Chest Radiographs

  • Jung Eun Huh; Jong Hyuk Lee;Eui Jin Hwang;Chang Min Park
    • Korean Journal of Radiology
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    • v.24 no.2
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    • pp.155-165
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    • 2023
  • Objective: Little is known about the effects of using different expert-determined reference standards when evaluating the performance of deep learning-based automatic detection (DLAD) models and their added value to radiologists. We assessed the concordance of expert-determined standards with a clinical gold standard (herein, pathological confirmation) and the effects of different expert-determined reference standards on the estimates of radiologists' diagnostic performance to detect malignant pulmonary nodules on chest radiographs with and without the assistance of a DLAD model. Materials and Methods: This study included chest radiographs from 50 patients with pathologically proven lung cancer and 50 controls. Five expert-determined standards were constructed using the interpretations of 10 experts: individual judgment by the most experienced expert, majority vote, consensus judgments of two and three experts, and a latent class analysis (LCA) model. In separate reader tests, additional 10 radiologists independently interpreted the radiographs and then assisted with the DLAD model. Their diagnostic performance was estimated using the clinical gold standard and various expert-determined standards as the reference standard, and the results were compared using the t test with Bonferroni correction. Results: The LCA model (sensitivity, 72.6%; specificity, 100%) was most similar to the clinical gold standard. When expert-determined standards were used, the sensitivities of radiologists and DLAD model alone were overestimated, and their specificities were underestimated (all p-values < 0.05). DLAD assistance diminished the overestimation of sensitivity but exaggerated the underestimation of specificity (all p-values < 0.001). The DLAD model improved sensitivity and specificity to a greater extent when using the clinical gold standard than when using the expert-determined standards (all p-values < 0.001), except for sensitivity with the LCA model (p = 0.094). Conclusion: The LCA model was most similar to the clinical gold standard for malignant pulmonary nodule detection on chest radiographs. Expert-determined standards caused bias in measuring the diagnostic performance of the artificial intelligence model.

Image Quality and Lesion Detectability of Lower-Dose Abdominopelvic CT Obtained Using Deep Learning Image Reconstruction

  • June Park;Jaeseung Shin;In Kyung Min;Heejin Bae;Yeo-Eun Kim;Yong Eun Chung
    • Korean Journal of Radiology
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    • v.23 no.4
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    • pp.402-412
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    • 2022
  • Objective: To evaluate the image quality and lesion detectability of lower-dose CT (LDCT) of the abdomen and pelvis obtained using a deep learning image reconstruction (DLIR) algorithm compared with those of standard-dose CT (SDCT) images. Materials and Methods: This retrospective study included 123 patients (mean age ± standard deviation, 63 ± 11 years; male:female, 70:53) who underwent contrast-enhanced abdominopelvic LDCT between May and August 2020 and had prior SDCT obtained using the same CT scanner within a year. LDCT images were reconstructed with hybrid iterative reconstruction (h-IR) and DLIR at medium and high strengths (DLIR-M and DLIR-H), while SDCT images were reconstructed with h-IR. For quantitative image quality analysis, image noise, signal-to-noise ratio, and contrast-to-noise ratio were measured in the liver, muscle, and aorta. Among the three different LDCT reconstruction algorithms, the one showing the smallest difference in quantitative parameters from those of SDCT images was selected for qualitative image quality analysis and lesion detectability evaluation. For qualitative analysis, overall image quality, image noise, image sharpness, image texture, and lesion conspicuity were graded using a 5-point scale by two radiologists. Observer performance in focal liver lesion detection was evaluated by comparing the jackknife free-response receiver operating characteristic figures-of-merit (FOM). Results: LDCT (35.1% dose reduction compared with SDCT) images obtained using DLIR-M showed similar quantitative measures to those of SDCT with h-IR images. All qualitative parameters of LDCT with DLIR-M images but image texture were similar to or significantly better than those of SDCT with h-IR images. The lesion detectability on LDCT with DLIR-M images was not significantly different from that of SDCT with h-IR images (reader-averaged FOM, 0.887 vs. 0.874, respectively; p = 0.581). Conclusion: Overall image quality and detectability of focal liver lesions is preserved in contrast-enhanced abdominopelvic LDCT obtained with DLIR-M relative to those in SDCT with h-IR.

A Study on the Growth Process and Cases Type of Smart Farm - Focused on the Case of Korea and Japan - (스마트팜의 발전과정과 유형별 사례 조사 - 한국과 일본의 사례를 중심으로 -)

  • Nam, Yun-Cheol
    • Journal of the Korean Institute of Rural Architecture
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    • v.26 no.2
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    • pp.37-46
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    • 2024
  • The city is developing into a smart city. Smart villages and smart farms are developing in rural areas. Architectural technology needs synergy with smart cities, smart villages, and smart factories (intelligent factories) to help architectural experts understand smart farms and build facilities and equipment. Smart farms require design and construction technology with architectural structure and function. The purpose of this study was to investigate the current status and cases of smart farms in Korea and to investigate cases abroad. The conclusion is as follows. ① Smart farms are developing rapidly. The Korean government is expanding smart farms by utilizing ICT technology and infrastructure. ② 'Smart Farm Innovation Valley', which has been promoted since 2018, is a cutting-edge convergence cluster industrial complex that integrates production, education, and research functions such as start-ups and technological innovation. ③ In domestic cases, smart farms are operated in subway stations, buildings, supermarkets, and restaurants. ④ In the Japanese case, a dome-type smart farm was being operated. It utilized factory wastewater, waste heat, renewable energy, and used new materials. Otemachi Ranch raised livestock and provided a lounge on the 13th floor of the building. ⑤ In the cases of Korea and Japan, the smart farm technology is very similar. As stated earlier, since the food culture and agricultural technology of both countries are similar, we hope to promote the development of smart farms that can reduce concerns about future food by communicating and sharing mutual technologies.

A Comparative Study on Anti-Obesity Efficacy of Cydonia oblonga Miller Fruit Extract in Diet-Induced Obesity Animal Models (식이유도 비만 동물모델에서 마르멜로추출물의 항비만 효능 비교 연구)

  • Jung Soon Hwang;Myeong Oh Hwang;Kisung Kwon;Eun Ji Kim
    • Journal of Korean Medicine for Obesity Research
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    • v.24 no.1
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    • pp.13-24
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    • 2024
  • Objectives: The objective of this study was to explore the anti-obesity effect of Cydonia oblonga Miller fruit extract (COME) and to compare its anti-obesity efficacy with Garcinia cambogia extract (GCE) in diet-induced obese mice. Methods: Five-week-old male C57BL/6 were allocated into four groups: control diet (CD), high-fat diet (HFD), HFD + 400 mg/kg body weight (BW)/day COME (H+C), or HFD + 400 mg/kg BW/day GCE (H+G) groups. COME or GCE was administered once a day by oral gavage for eight weeks. Body weight, body fat percentage, fat weight, and biochemical parameters in serum were measured. The expressions of transcription factors and their target genes in epididymal adipose tissues were analyzed by reverse transcription polymerase chain reaction. Results: COME reduced body weight, weight gain, body fat percentage, total white adipose tissue weight, adipocyte size, and serum levels of insulin and leptin in high-fat diet-induced obese C57BL/6 mice. COME suppressed the mRNA expressions of CCAAT/enhancer binding proteinα, peroxisome proliferator-activated receptorγ, sterol-regulatory element-binding protein-1c, fatty acid synthase, and adipocyte protein 2 and increased carnitine palmitoyl transferase 1 mRNA expression in epidydimal adipose tissues. The anti-obesity efficacy of COME was found to be similar to that of GCE at the same dose. However, COME more effectively decreased adipose tissue weights, epididymal adipocyte size, serum insulin and leptin compared to GCE. Conclusions: These results demonstrated that COME is not toxic and exhibits anti-obesity efficacy at a level similar to that of GCE, suggesting that COME may be applicable as an anti-obesity agent.

Transitioning from the Posterior Approach to the Direct Anterior Approach for Total Hip Arthroplasty

  • Cameron M. Metzger;Hassan Farooq;Jacqueline O. Hur;John Hur
    • Hip & pelvis
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    • v.34 no.4
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    • pp.203-210
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    • 2022
  • Purpose: Total hip arthroplasty (THA) using the direct anterior approach (DAA) is known to have a learning curve. The purpose of this study was to review cases where surgery was performed by an arthroplasty surgeon transitioning from the posterior approach (PA) to the DAA. We hypothesized similar complication rates and improvements in surgical duration over time. Materials and Methods: A review of 2,452 consecutive primary THAs was conducted. Surgical duration, length of stay (LOS), surgical complications, decrease in postoperative day (POD) 1 hemoglobin, transfusion rates, POD 0 and POD 1 pain scores, incision length, leg length discrepancy (LLD), and radiographic cup position were recorded. Results: No differences in surgical duration were observed after the first 50 DAA cases. A shorter LOS was observed for the DAA, and statistical difference was appreciated after the first 100 DAA cases. There were no differences in periprosthetic fractures. A higher rate of infections and hip dislocations were observed with the PA. The PA showed an association with higher transfusion rates without significant difference in POD 1 decrease in hemoglobin over the first 100 DAA cases. Similar POD 0 and POD 1 pain scores with a smaller incision were observed for the first 100 DAA cases. The DAA cohort showed less variation in cup inclination, version, and LLD. Conclusion: DAA is safe and non-inferior in terms of reduced LOS, smaller incision, and less variation in cup position. Fifty DAA cases was noted to be the learning curve required before no differences in duration between approaches were observed.

Development of Composite Flours and Their Products Utilizing Domestic Raw Materials - I. Physical and Chemical Properties and Nutritional Test of Composite Flour Materials - (국산원료(國産原料)를 활용(活用)한 복합분(複合粉) 및 제품개발(製品開發)에 관한 연구(硏究) - 제 1 보 원료분(原料粉)의 이화학적성상(理化學的性狀) 및 영양시험(營養試驗) -)

  • Kim, Hyong-Soo;Lee, Kwan-Young;Kim, Sung-Kih;Lee, Su-Rae
    • Korean Journal of Food Science and Technology
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    • v.5 no.1
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    • pp.6-15
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    • 1973
  • In an attempt to develop composite flours based on raw materials available in Korea, six domestic resources were investigated with respect to their physical and chemical properties, nutritive value and economy. The results are summarized as follows: 1) Flours from naked barley, sweet potato, potato, corn, defatted rice bran and defatted soybean were compared in respect of their proximate composition, thiamine content and protein score. 2) In color comparison, naked barley and defatted soy flours were comparable to wheat flour whereas corn and sweet potato flours were a little inferior. In raising power, naked barley and defatted soy flours were similar to wheat flour and others were inferior. 3) In maximum viscosity of flours by amylograph, naked barley, corn and potato flours were higher than wheat flour and others were lower. In viscosity in cooling, corn flour was similar to wheat flour and naked barley and potato flours were lower. Addition of $10{\sim}20%$ defatted soy flour into other flours generally caused the lowering of viscosity. Addition of emulsifiers such as glyceryl monostearate, calcium stearyl lactylate, Methocel and Emulthin into the flours manifested different effects on the amylogram. 4) In nutritional test by rat, diets consisting of naked barley, sweet potato, potato or corn flours, each containing defatted soy flour (at 10% level with exception of 20% for sweet potato flour) and naked barley flour fortified with lysine were similar to wheat flour in digestibility, but were superior in NPU and biological value. 5) In price estimation, sweet potato and corn flours were competitive with wheat flour, but naked barley flour was a little expensive. On the other hand, barley and sweet potato are promising in terms of domestic production.

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A Study on the Foot Wear -On the Tadzhik of central Asia- (중앙아시아의 신에 관한 연구 -타지크(Tadzhik)를 중심으로-)

  • 정하신
    • Journal of the Korean Home Economics Association
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    • v.28 no.1
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    • pp.21-41
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    • 1990
  • All the cultures are enriched and developed themselves through the contact with another culture, which propagate and transplant its new cultural elements to a time-honoured tradition. Therefore, the investigation of the origin of each culture means to find out the all the elements of each culture itself in the end. In Korean Costume, we can find both the Costume of frizid jone and that of temperate jone togther, effected by the influence of typical continental climate. Accordingly, we can also realize that both Lee, of southern tribe and Haw, of northern tribe suitable for the protection of cold weather, existed in Korea. Even Lee and Hwa were used together, Hwa had been appeared earlier than Lee along with the Skitai Costume and we can find its origin in the line of Skitai costume. In Central Asia, Tadjhik was the only race tracing their ancestry from ancient Iranic genuinely and they had been keeping the culture of Skitai origin continuously. The purpose of this thesis is to examine Korean's own culture of the footwear through the investigation of Tadjhik's culture of costume, specially through the culture of Tadjhik footware. To reach the conclusion of this thesis, the comparision and investigation between Korea and Tadjhik was made carefully for the followings, culture of life and costume, forms and materials of footwear. 1. The treasers and boots made by leather and felt was the origin of costume culture of Central Asia and aboves were appeared in persian costumn for the first time. We can consider that those had connection with Korean culture of costume. 2. Form of Tadjhik footwear can be devided by hwa and Lee, and there was a big difference in form between that of mountain area and plain area. We can find more rariety in footwear of mountain area. 3. If we compare the form of Hwa and Lee of Tadjhik with our own footwear, we can find out many things in common and there are lots of similarities particularly in form and material. 4. We can say that the difference of Tadjhik and Korean was the preference of Hwa for Tadjhik and Lee for Korean, aboves came from the different totography, climate condition and life style. 5. The form of male and female footwear of tadjhik was almost similar, but female footwear had various and beautiful decorations for the ornament. 6. The materials of Tadjhik footwear was mostly leather, and Hwa was used particularly for labour purposes. 7. We can expect that Tadjhik of Central Asia and Korea had a similar orgin and style on the footwear. It can be expected that we can find out many common things in further investigation of the study of Tadjhik costume and will exert the examination continuously.

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