• Journal of Sensor Science and Technology
• /
• v.31 no.5
• /
• pp.348-352
• /
• 2022

Hydrogen gas (H₂) which is odorless, colorless is attracting attention as a renewable energy source in varions applications but its leakage can lead to disastrous disasters, such as inflammable, explosive, and narcotic disasters at high concentrations. Therefore, it is necessary to develop H₂ gas sensor with high performance. In this paper, we confirmed that H₂ gas detection ability of SnO₂ based H₂ gas sensor along with thermal treatment effect of SnO₂. Proposed SnO₂ based H₂ gas sensor is fabricated by MEMS technologies such as photolithgraphy, sputtering and lift-off process, etc. Deposited SnO₂ thin films are thermally treated in various thermal treatement temperature in range of 500-900 ℃ and their H₂ gas detection ability is estimatied by measuring output current of H₂ gas sensor. Based on experimental results, fabricated H₂ gas sensor with SnO₂ thin film which is thermally treated at 700 ℃ has a superior H₂ gas detection ability, and it can be expected to utilize at the practical applications.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.615-624
• /
• 2022

In this study, we assessed anti-oxidant activity, anti-microbial, inhibition of biofilm formation and inflammatory factors(nitric oxide, interleukin-6, interleukin-8) inhibitory effect of Perillae semen hydrothermal extract(PSW) and three kinds of Perillae semen supercritical fluid extract(PSSs) extracted by controlling temperature with no variation of pressure. Compared with PSW, PSSs had significantly lower minimal inhibitory concentrations(MICs) against Staphylococcus aureus(S. aureus) and the ability of PSSs to inhibit formation of biofilm was also superior. PSSs reduce the production of inflammatory mediator and inflammatory cytokines significantly compared to PSW. We suggest, therefore, Perillae semen supercritical fluid 45℃ extract which showed the best anti-microbial, inhibition of biofilm formation, and inhibition of inflammatory factors production among the supercritical fluid extracts could be used for protecting patients with atopic dermatitis from pruritus and transepidermal water loss as a functional ingredient from nature.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.6
• /
• pp.605-614
• /
• 2022

In this study, oregano was extracted by supercritical extraction and hydrothermal extraction method. In vitro experiments such as antimicrobial and antioxidant activity test were performed. As a result of the disc diffusion method, only the supercritical extracts formed a clear zone. The MIC for S. aureus was found only in the supercritical fluid extracts and it was 1000 ㎍/mL. The hydrothermal extract's MIC is 125 ㎍/mL for C. acnes. Through biofilm inhibition assay, we found that the supercritical fluid oregano extracts inhibit the biofilm of S. aureus by more than 70% even at low concentrations of 125 ㎍/mL. On the other hand, the antioxidant ability of the hydrothermal extract was better than that of the supercritical fluid extracts. Furthermore, we tried to make a skincare ingredient for atopic dermatitis by utilizing the S. aureus biofilm inhibitory ability of oregano supercritical fluid extracts. Liposome was used to overcome the low solubility of the oregano supercritical fluid extracts and increase stability.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.2
• /
• pp.15-20
• /
• 2023

Recently, digitalization is accelerating in all industries, and the use of information and personal information produced and used in the process of it is very important for the success or failure of a company. However, malicious attempts to steal or leak major information and personal information of a company as an adverse effect continue to increase, and appropriate defense and response are absolutely necessary. However, in the case of small and medium-sized enterprises, the priority of information protection and the possession of professional manpower are very insufficient compared to large enterprises. This paper studies the certification and audit implemented in Korea, and suggests ways to expand the certification of the information protection system suitable for SMEs and improve the effectiveness of the support system through the expansion of the privacy law notification standard and operation of support system.

• Imaging Science in Dentistry
• /
• v.52 no.4
• /
• pp.351-357
• /
• 2022

Purpose: Convolutional neural networks (CNNs) have rapidly emerged as one of the most promising artificial intelligence methods in the field of medical and dental research. CNNs can provide an effective diagnostic methodology allowing for the detection of early-staged diseases. Therefore, this study aimed to evaluate the performance of a deep CNN algorithm for apical lesion segmentation from panoramic radiographs. Materials and Methods: A total of 1000 panoramic images showing apical lesions were separated into training (n=800, 80%), validation (n=100, 10%), and test (n=100, 10%) datasets. The performance of identifying apical lesions was evaluated by calculating the precision, recall, and F1-score. Results: In the test group of 180 apical lesions, 147 lesions were segmented from panoramic radiographs with an intersection over union (IoU) threshold of 0.3. The F1-score values, as a measure of performance, were 0.828, 0.815, and 0.742, respectively, with IoU thresholds of 0.3, 0.4, and 0.5. Conclusion: This study showed the potential utility of a deep learning-guided approach for the segmentation of apical lesions. The deep CNN algorithm using U-Net demonstrated considerably high performance in detecting apical lesions.

• Journal of the Korean Regional Science Association
• /
• v.39 no.1
• /
• pp.21-36
• /
• 2023

Entering the era of low growth due to changes in social and economic conditions, most cities across the country are actively promoting urban regeneration. Although urban regeneration is a project with huge national finances, a clear evaluation system has not yet been established. In order to ensure the sustainability of urban regeneration, it is necessary to secure the validity of urban regeneration policies and establish a reflux system to supplement the policies. The purpose of this study is to derive the limitations of the existing comprehensive performance evaluation and to develop an improved urban regeneration policy comprehensive performance evaluation technique based on spatial big data. The urban regeneration comprehensive performance evaluation technique differentiated the areas affected by the urban regeneration project and the surrounding areas based on the type of urban regeneration project and the presence or absence of large cities and middle cities. The effects of urban regeneration were quantitatively verified through relative comparison between the areas affected by urban regeneration projects and the surrounding areas of population, society, economy, industry, physical and environmental evaluation indicators.

• Archives of Craniofacial Surgery
• /
• v.24 no.1
• /
• pp.37-40
• /
• 2023

Penetrating wounds to the face are cosmetically devastating and can be life-threatening. If the foreign body causing the penetrating wound is a piece of wood, small remnants might be left behind after the initial treatment. A 33-year-old male patient presented to the emergency center after a piece of lumber pierced his face as a passenger in a traffic accident. The patient's vital signs were stable, and emergency surgery was performed to remove the foreign body and repair the soft tissue. No noteworthy complications were seen after open reduction and internal fixation of the facial bone fractures. Seven months after the accident, the patient underwent scar revision along with full-thickness skin grafting for post-traumatic scars. After the surgery, pus-like discharge which was not previously present was observed, and the graft did not take well. A residual foreign body, which was the cause of graft failure, was found on computed tomography and the remaining foreign body was removed through revision surgery. The patient is receiving outpatient follow-up without any complications 6 months after surgery. This case demonstrates the importance of performing a careful evaluation to avoid missing a residual foreign body, especially if it is of wooden nature.

• Archives of Craniofacial Surgery
• /
• v.24 no.1
• /
• pp.10-17
• /
• 2023

Background: Lipomas are common benign tumors of mesenchymal origin that are composed of mature adipocytes. Giant lipomas have a diameter ≥ 10 cm in one or more dimensions or weigh at least 1,000 g. The surgical excision of a giant lipoma requires extensive dissection, increasing the risk of a seroma, which can cause surgical site complications such as wound infection and necrosis. Sclerotherapy with Abnobaviscum (Viscum album extract) is a relatively new technique used to reduce malignant pleural effusion. In this study, we evaluated the effectiveness of prophylactic sclerotherapy using Abnobaviscum to decrease seroma after giant lipoma excision. Methods: We conducted a retrospective medical record review of patients who underwent surgical excision for giant lipoma of the neck from January 2019 to December 2022. Sclerotherapy was performed on the first postoperative day in patients who consented to the procedure, and Abnobaviscum was instilled through the existing Hemovac drain. We compared the clinical course between those who underwent postoperative sclerotherapy and those who did not. Results: Among the 30 patients who underwent giant lipoma excision, we applied sclerotherapy with Abnobaviscum to 15 patients. The average time from surgery to Hemovac removal was statistically shorter in patients who underwent sclerotherapy (p= 0.004). Furthermore, seroma formation was significantly reduced in patients receiving sclerotherapy (p= 0.003). Conclusion: In patients undergoing giant lipoma excision, sclerotherapy using Abnobaviscum helps reduce postoperative seroma formation during the initial postoperative period. It can be an excellent method to reduce complications related to seroma and attenuate patients' postoperative burden.

• Journal of the Korean Geotechnical Society
• /
• v.24 no.12
• /
• pp.85-92
• /
• 2008

It is necessary to develop a rational design method for surface reinforcement of very soft ground because most current design works rely on merely crude empirical correlations. In this paper, the mechanical behavior of very soft ground that is surficially reinforced was investigated with the aid of a series of numerical analyses. Several material properties of each dredged soft ground, reinforcement and backfill sand mat have been exercised in the numerical analysis. The result of numerical analysis was compared with those of the laboratory model test. Through the matching process between the numerical and experimental result, it is possible to determine representative material properties of the dredged soft ground, reinforcements and backfill sand mat. These verified material properties permit to evaluate the effect of the stiffness of reinforcement and the thickness of sand mat on the overall deformation of the reinforced soft ground.

• Journal of the Korean Geotechnical Society
• /
• v.25 no.5
• /
• pp.17-28
• /
• 2009

When embankments are constructed on soft clay deposit, unsymmetrical surcharges due to embankments may generate the excessive vertical settlement and lateral deformation of soft clay foundation. The excessive deformations in soft grounds cause not only stability problem of the embankment itself but also that of the adjacent structures. The objectives of this research are to study the deformational behavior of soft ground due to the embankment load with different loading and soil conditions. Five model tests are carried out with different test conditions. From the results of the model tests, it is concluded that the lateral displacement induced by the embankment load occurs in the range of two times of the embankment width from a toe. In addition, the relationship between loading rate, v, and the vertical settlement of the soft ground, ${\Delta}s$, and the lateral displacement at the toe of embankment, ${\Delta}y_m$, is investigated based on the model test results.