• Journal of the Korean institute of surface engineering
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• v.57 no.1
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• pp.38-48
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• 2024

We fabricated In₂O₃ zig-zag nanocolumns(ZZNCs) by oblique angle deposition method based on e-beam evaporator for highly sensitive and selective CH₃COCH₃ sensor. Our results indicate that as the ZZNCs layer stacks, the gas response also increases. In comparison to thin films, ZZNCs at 5 layer show a 117-fold enhancement in gas response and a rapid response time (~2 s). When measured with various gases, it showed a high selectivity towards acetone. Under conditions of 80% R.H., exposure to CH₃COCH₃ gas theoretically indicated a detection limit of 1.2 part-per-billion(ppb). These results suggest the potential of In₂O₃ ZZNCs as a breath analyzer for the diagnosis of diabetes.

• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.781-789
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• 2009

The absorption coefficients of the materials used in a 1:50 scale model multipurpose hall were measured based on ISO 354 and related laws. The shape and materials for the scale model were evaluated based on reflective surfaces, variable acoustic elements and sound-absorbing quality (125Hz-1kHz average) of seats. The measured average absorption coefficients of audience seats, audience and orchestra were 0.64, 0.74 and 0,45, respectively, which were simulated with the combination of wood, absorption materials and foam board. Various mounting methods for absorption curtain and banner were considered according to the installation methods. The average absorption coefficient was measured as 0.42, 0.47 and 0.45 in the conditions of Type A mounting, E mounting with 0.9 m backing air cavity, and Type G mounting which is suspended at the ceiling, respectively. It was confirmed that the absorption coefficient was increased at low frequency by backing air gap. The finishing material of stage house was an absorption material covered with thin fabric, which aimed average absorption coefficient of 0.68 by using fiber glass board. Each part of the real materials was compared with those of 1:50 scale model and it was found that the absorption characteristics of both cases were similar.

• Journal of Korean Medical classics
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• v.37 no.2
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• pp.49-76
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• 2024

Objectives : The purpose of this paper is to examine the mechanism and treatment of the Zangfu warm disease in the Beijiqianjinyaofang. Methods : This study examined the Zangfu warm disease content in the Beijiqianjinyaofang, Shanghanzongbinglun, Saninfang, based on the Neijing explanation of the pathological mechanism. Treatment was analyzed among the three texts in terms of their similarity and difference. Results & Conclusions : 1. Zangfu warm disease is caused by seasonally inappropriate qi, which is infectious, epidemic, and seasonal. 2. While the Qingjinqian disease pattern was explained in terms of the relationship between Shaoyin and Shaoyang, the actual disease pattern happened more in the Taiyang channel, and partly in the Shaoyang channel. For treatment of Fu deficiency pattern, the Chaihudihuangtang was listed in the Qianjinyaofang and the Shanghanzongbinglun, while in the Sanyinfang, the formula was modified to extinguish heat and thin phlegm, while reinforcing healthy qi. 3. The Chimaifei disease pattern was explained in terms of the relationship between Shaoyin and Taiyang that is deeply associated with Wei qi. For treatment of Fu deficiency the Qianjinyaofang and Shanghanzongbinglun used the Shigaodihuangtang, while the Sanyinfang reinforced healthy qi and eliminated pathogenic qi. 4. The Huangrousui disease pattern was explained as being caused by problems in the Taiyin and Yangming, in which the Triple Burner fails to control and manage cold dampness. In treating Zang excessiveness, the Qianjinyaofang and Shanghanzongbinglun used the Xuanshenhanshuishitang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. In treating Fu deficiency, the Sanyinfang instructed to warm the center and dry dampness, tonifying the Spleen and reinforcing qi. 5. The Baiqili disease pattern was explained within the relationship between Taiyin and Taiyang. In treating Fu deficiency, the Qianjinyaofang and Shanghanzongbinglun used the Shigaoxingrentang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. In treating Zang excessiveness, the Qianjinyaofang and Shanghanzongbinglun used the Shigaocongbaitang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. 6. The Heiguwen disease pattern was explained as being caused by stagnation and obstruction in the Triple Burner due to clash between Taiyang and Shaoyin. In treating Zang excessiveness, the Qianjinyaofang and Shanghanzongbinglun used the Kushenshigaotang, while the Sanyinfang instructed to reinforce healthy qi and eliminate pathogenic qi. The Zangfu Warm Disease is a infectious disease concept which is based on the Five Zang that integrates the meridian aspect together with the Six Fu with which there is an external/internal relationship. This concept and treatment could be considered in dealing with COVID-19.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.1-10
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• 2024

In a previous study, a structure of a superplastic yoke consisting of a thin FR4 layer laminated with viscoelastic tape on both sides of a shape memory alloy (SMA) was proposed to reduce residual vibration generated by a deployable solar panel during high motion of a satellite. Damping properties of viscoelastic tapes will change with temperature, which can directly affect vibration reduction performance of the yoke. To check damping performance of the yoke at different temperatures, free damping tests were performed under various temperature conditions to identify the temperature range where the damping performance was maximized. Based on above temperature test results, this paper predicts temperature of the yoke through orbital thermal analysis so that the yoke can have effective damping performance even if it is exposed to an orbital thermal environment. In addition, the thermal design method was described so that the yoke could have optimal vibration reduction performance.

• Membrane Journal
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• v.34 no.1
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• pp.70-78
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• 2024

A photo-crosslinked anion exchange membrane (AEM) based on quaternary-aminated polyacrylates was developed for reverse electrodialysis (RED). Although reverse electrodialysis is a clean and renewable energy generation system, the low power output and high membrane cost are serious obstacles to its commercialization. Cross-linked AEMs without any polymer supporters were fabricated through photo-crosslinking between polymer-typed acrylates with anion conducting groups, in particular, polymer-typed acrylates were synthesized based on engineering plastic with outstanding mechanical and chemical property. The fabricated membranes showed outstanding physical, chemical, and electrochemical properties. The area resistance of the fabricated membranes (CQAPPOA-20, CQAPPOA-35, and CQAPPOA-50) were ~50% lower than that of AMV (2.6 Ω cm²). Moreover, the transport number of CQAPPOA-35 wase comparable to that of AMV, despite the thin thickness (40 ㎛) of the fabricated membranes. The RED stack with the CQAPPOA-35 membrane provided an excellent maximum power density of 2.327 W m^-2 at a flow rate of 100 mL min^-1, which is 15% higher than that (2.026 W m^-2) of the RED stack with the AMV membrane. Considering easy fabrication process by UV photo-crosslinking and outstanding RED stack properties, the CQAPPOA-35 membrane is a promising candidate for REDs.

• Korean Journal of Radiology
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• v.22 no.12
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• pp.1996-2005
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• 2021

Objective: To investigate the multidetector computed tomography (MDCT) features of fumarate hydratase-deficient renal cell carcinoma (FH-deficient RCC) with germline or somatic mutations, and compare them with those of papillary type II RCC (pRCC type II). Materials and Methods: A total of 24 patients (mean ± standard deviation, 40.4 ± 14.7 years) with pathologically confirmed FH-deficient RCC (15 with germline and 9 with somatic mutations) and 54 patients (58.6 ± 12.6 years) with pRCC type II were enrolled. The MDCT features were retrospectively reviewed and compared between the two entities and mutation subgroups, and were correlated with the clinicopathological findings. Results: All the lesions were unilateral and single. Compared with pRCC type II, FH-deficient RCC was more prevalent among younger patients (40.4 ± 14.7 vs. 58.6 ± 12.6, p < 0.001) and tended to be larger (8.1 ± 4.1 vs. 5.4 ± 3.2, p = 0.002). Cystic solid patterns were more common in FH-deficient RCC (20/24 vs. 16/54, p < 0.001), with 16 of the 20 (80.0%) cystic solid tumors having showed typical polycystic and thin smooth walls and/or septa, with an eccentric solid component. Lymph node (16/24 vs. 16/54, p = 0.003) and distant (11/24 vs. 3/54, p < 0.001) metastases were more frequent in FH-deficient RCC. FH-deficient RCC and pRCC type II showed similar attenuation in the unenhanced phase. The attenuation in the corticomedullary phase (CMP) (76.3% ± 25.0% vs. 60.2 ± 23.6, p = 0.008) and nephrographic phase (NP) (87.7 ± 20.5, vs. 71.2 ± 23.9, p = 0.004), absolute enhancement in CMP (39.0 ± 24.8 vs. 27.1 ± 22.7, p = 0.001) and NP (50.5 ± 20.5 vs. 38.2 ± 21.9, p = 0.001), and relative enhancement ratio to the renal cortex in CMP (0.35 ± 0.26 vs. 0.24 ± 0.19, p = 0.001) and NP (0.43 ± 0.24 vs. 0.29 ± 0.19, p < 0.001) were significantly higher in FH-deficient RCC. No significant difference was found between the FH germline and somatic mutation subgroups in any of the parameters. Conclusion: The MDCT features of FH-deficient RCC were different from those of pRCC type II, whereas there was no statistical difference between the germline and somatic mutation subgroups. A kidney mass with a cystic solid pattern and metastatic tendency, especially in young patients, should be considered for FH-deficient RCC.

• Korean Journal of Radiology
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• v.22 no.4
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• pp.624-633
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• 2021

Objective: To evaluate the reliability of CT measurements of muscle quantity and quality using variable CT parameters. Materials and Methods: A phantom, simulating the L2-4 vertebral levels, was used for this study. CT images were repeatedly acquired with modulation of tube voltage, tube current, slice thickness, and the image reconstruction algorithm. Reference standard muscle compartments were obtained from the reference maps of the phantom. Cross-sectional area based on the Hounsfield unit (HU) thresholds of muscle and its components, and the mean density of the reference standard muscle compartment, were used to measure the muscle quantity and quality using different CT protocols. Signal-to-noise ratios (SNRs) were calculated in the images acquired with different settings. Results: The skeletal muscle area (threshold, -29 to 150 HU) was constant, regardless of the protocol, occupying at least 91.7% of the reference standard muscle compartment. Conversely, normal attenuation muscle area (30-150 HU) was not constant in the different protocols, varying between 59.7% and 81.7% of the reference standard muscle compartment. The mean density was lower than the target density stated by the manufacturer (45 HU) in all cases (range, 39.0-44.9 HU). The SNR decreased with low tube voltage, low tube current, and in sections with thin slices, whereas it increased when the iterative reconstruction algorithm was used. Conclusion: Measurement of muscle quantity using HU threshold was reliable, regardless of the CT protocol used. Conversely, the measurement of muscle quality using the mean density and narrow HU thresholds were inconsistent and inaccurate across different CT protocols. Therefore, further studies are warranted in future to determine the optimal CT protocols for reliable measurements of muscle quality.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.476-488
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• 2021

Objective: We aimed to develop a deep neural network for segmenting lung parenchyma with extensive pathological conditions on non-contrast chest computed tomography (CT) images. Materials and Methods: Thin-section non-contrast chest CT images from 203 patients (115 males, 88 females; age range, 31-89 years) between January 2017 and May 2017 were included in the study, of which 150 cases had extensive lung parenchymal disease involving more than 40% of the parenchymal area. Parenchymal diseases included interstitial lung disease (ILD), emphysema, nontuberculous mycobacterial lung disease, tuberculous destroyed lung, pneumonia, lung cancer, and other diseases. Five experienced radiologists manually drew the margin of the lungs, slice by slice, on CT images. The dataset used to develop the network consisted of 157 cases for training, 20 cases for development, and 26 cases for internal validation. Two-dimensional (2D) U-Net and three-dimensional (3D) U-Net models were used for the task. The network was trained to segment the lung parenchyma as a whole and segment the right and left lung separately. The University Hospitals of Geneva ILD dataset, which contained high-resolution CT images of ILD, was used for external validation. Results: The Dice similarity coefficients for internal validation were 99.6 ± 0.3% (2D U-Net whole lung model), 99.5 ± 0.3% (2D U-Net separate lung model), 99.4 ± 0.5% (3D U-Net whole lung model), and 99.4 ± 0.5% (3D U-Net separate lung model). The Dice similarity coefficients for the external validation dataset were 98.4 ± 1.0% (2D U-Net whole lung model) and 98.4 ± 1.0% (2D U-Net separate lung model). In 31 cases, where the extent of ILD was larger than 75% of the lung parenchymal area, the Dice similarity coefficients were 97.9 ± 1.3% (2D U-Net whole lung model) and 98.0 ± 1.2% (2D U-Net separate lung model). Conclusion: The deep neural network achieved excellent performance in automatically delineating the boundaries of lung parenchyma with extensive pathological conditions on non-contrast chest CT images.

• Korean Journal of Radiology
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• v.22 no.3
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• pp.464-475
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• 2021

Objective: This study aimed to evaluate the tumor doubling time of invasive lung adenocarcinoma according to the International Association of the Study for Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) histologic classification. Materials and Methods: Among the 2905 patients with surgically resected lung adenocarcinoma, we retrospectively included 172 patients (mean age, 65.6 ± 9.0 years) who had paired thin-section non-contrast chest computed tomography (CT) scans at least 84 days apart with the same CT parameters, along with 10 patients with squamous cell carcinoma (mean age, 70.9 ± 7.4 years) for comparison. Three-dimensional semiautomatic segmentation of nodules was performed to calculate the volume doubling time (VDT), mass doubling time (MDT), and specific growth rate (SGR) of volume and mass. Multivariate linear regression, one-way analysis of variance, and receiver operating characteristic curve analyses were performed. Results: The median VDT and MDT of lung cancers were as follows: acinar, 603.2 and 639.5 days; lepidic, 1140.6 and 970.1 days; solid/micropapillary, 232.7 and 221.8 days; papillary, 599.0 and 624.3 days; invasive mucinous, 440.7 and 438.2 days; and squamous cell carcinoma, 149.1 and 146.1 days, respectively. The adjusted SGR of volume and mass of the solid-/micropapillary-predominant subtypes were significantly shorter than those of the acinar-, lepidic-, and papillary-predominant subtypes. The histologic subtype was independently associated with tumor doubling time. A VDT of 465.2 days and an MDT of 437.5 days yielded areas under the curve of 0.791 and 0.795, respectively, for distinguishing solid-/micropapillary-predominant subtypes from other subtypes of lung adenocarcinoma. Conclusion: The tumor doubling time of invasive lung adenocarcinoma differed according to the IASCL/ATS/ERS histologic classification.

• Journal of Advanced Technology Convergence
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• v.3 no.2
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• pp.25-31
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• 2024

In recent industrialization and development due to information and communication technology, modern women in modern society are exposed to physical and mental health due to numerous stresses. Popular inflammations are attributable to a decrease in lactic acid bacteria, frequent antibiotic use, and a decrease in immunity. It is necessary to develop products that are helpful and reflected. The inner care gel currently introduced on the market can increase beneficial bacteria and maintain a healthy y-zone. The inner gel contains a hydrogel component. 90% is made up of water, and other components act as support for supporting water and are formed through crosslinking between polymer chains. Hydroxyethyl cellulose (HEC) is a hydroxyethyl ethylenetel of cellulose. The purpose of use is to act as a binder, an emulsion stabilizer, a viscosity enhancer (water-soluble), and a film forming agent. CA (crosslinker) is a crosslinking agent and serves to bind. Hydrogel in the beauty field acts as a film forming agent that gently wraps around the skin by forming a thin film and serves as an emulsion stabilizer that helps to prevent separation of other raw materials. It also acts as a thickener by increasing viscosity in cosmetics. In addition, it is used for glucose monitoring, nursing care, cell transplantation, and wound treatment in the bio field. Currently, it is understood that no products using functional hydrogel have been released, so in this study, a Y zone care hydrogel solution was manufactured to find out the antibacterial properties of the functional hydrogel, and a new solution was developed. As a result, it was confirmed that the appropriate Ph was applied to the Y zone, and after culturing Candida albicans in PDB medium, all three products of the Y zone care hydrogel solution showed an antibacterial effect of 0.5-1.0mm