• 한국축산식품학회지
• /
• 제39권3호
• /
• pp.510-519
• /
• 2019

The effect of combined electron-beam irradiation and aging temperature of pork on microbiological and physicochemical properties was investigated. The samples from pork shoulder were irradiated with 0 or 2 kGy, vacuum-packaged, and assigned randomly to an aging temperature ($2^{\circ}C$, $10^{\circ}C$, or $25^{\circ}C$) during 8 d. On 4 d of aging at $25^{\circ}C$, total aerobic bacteria of non-irradiated ones reached 7 Log CFU/g which is no salable levels. Shear force values of irradiated meat after aging for 2 and 4 d at $25^{\circ}C$ was lower than those aged at $2^{\circ}C$. Irradiated samples at $2^{\circ}C$ had lower cooking loss after 2 and 8 d of aging, compared with other aging temperatures. Irradiation did not accelerate 2-thiobarbituric acid reactive substance (TBARS) value when aged up to 4 d. Irradiated samples aged at $10^{\circ}C$ and $25^{\circ}C$ for 8 d scored significantly higher TBARS values. With an increased aging period, $a^*$ and $b^*$ in irradiated samples at $2^{\circ}C$ slightly increased, but irradiation caused negligible changes in meat color. The highest contents of a desirable nucleotide flavor compounds (inosine-5-phosphate) were observed in pork at $2^{\circ}C$ when aged for 4 and 8 d, while the lowest contents were observed at $25^{\circ}C$. Aging in irradiated pork for 8 d at $2^{\circ}C$ resulted in optimal condition with improved meat quality and minimal microbiologically negative defect.

• 한국인터넷방송통신학회논문지
• /
• 제19권1호
• /
• pp.197-202
• /
• 2019

소형 밀리미터파 추적 레이다용 전원공급기는 리플노이즈가 최소인 안정적인 전원을 공급해야 하며 DC-DC 변환기의 스위칭 주파수 노이즈가 False Alarm 과 Ghost 를 유발하지 않고 운영중 모니터링을 통한 실시간 자체점검 기능을 보유하고 있어야 한다. 본 연구에서는 소형 밀리미터파 추적 레이다에 적용하기 위하여 +28VDC 입력을 받아서 최대 출력 ${\bigcirc}{\bigcirc}{\bigcirc}W$, 효율 80% 이상(@100%부하), 출력 전원 10개의 다중 출력 스위칭 전원공급기를 개발하였고 효율 80% 이상을 달성하기 위하여 전력이 큰 출력에 대해서는 DC-DC 변환기를 적용하였고 나머지 소전력 출력에 대해서는 다중 출력 플라이백 방식을 적용하여 설계 제작하여 시험 결과 100% 부하조건에서 85%의 우수한 효율 특성을 확인하였다.

• Archives of Plastic Surgery
• /
• 제46권3호
• /
• pp.221-227
• /
• 2019

Background Gynecomastia is a common condition that can cause severe emotional and physical distress in both young and older men. Patients in whom symptomatic recalcitrant gynecomastia persists for a long time are potential candidates for surgery. Methods From January 2014 to January 2016, 15 patients underwent correction of gynecomastia through a single 3-mm incision at our institution. Only patients with true gynecomastia underwent surgery with this new technique. Through the small incision, sharp dissection was performed in a clockwise and counterclockwise direction describing two half-circles. Health-related quality of life and aesthetic outcomes were evaluated using a modified version of the Breast Evaluation Questionnaire (BEQ). Results The patients' average age was 23.5 years (range, 18-28 years), and their average body mass index was $23.2kg/m^2$ (range, $19.2-25.3kg/m^2$). One case was unilateral and 14 cases were bilateral. The weight of glandular tissue resected from each breast ranged from 80 to 170 g. No excess skin was excised. Bleeding was minimal. The mean operating time was 25 minutes (range, 21-40 minutes). No complications were recorded. All lesions were histologically benign. The patients' average score was 3.5 (on a 5-point Likert scale) in all domains of the BEQ for themselves and their partners. Conclusions In this study, we demonstrated the safety and reliability of a new technique that allows mastectomy through an imperceptible 3-mm incision. We obtained high patient satisfaction scores using our surgical technique, and patients reported considerable improvement in their social, physical, and psychological well-being after surgery.

• 한국전산구조공학회논문집
• /
• 제33권6호
• /
• pp.375-382
• /
• 2020

적외선 유도 무기 체계의 발달로 항공기의 생존성은 지속적으로 위협받고 있으며, 항공기의 생존성을 향상시키기 위한 적외선 스텔스 기술 관련 연구가 진행되고 있다. 본 논문에서는 적외선 유도 미사일이 항공기와 배경 간의 대비 신호를 탐지하는 것에 주목하여 비행 조건에 따른 항공기의 최적 적외선 신호를 분석하고자 하였다. 이를 위해 항공기의 비행 조건을 고려하여 유동 해석과 대류, 전도, 복사 3차원 열전달 해석을 수행하였고, 동체 표면 온도를 도출하여 항공기 주변 유동 특성을 기반으로 항공기의 적외선 신호를 분석하였다. 더 나아가, 비행 조건 별로 최적 적외선 신호를 갖기 위한 최적 방사율을 도출하였고, 비행 조건 별로 최적 방사율을 동체 표면에 적용했을 때 적외선 신호 저감 효과를 분석하였다.

• 디지털융복합연구
• /
• 제19권3호
• /
• pp.25-35
• /
• 2021

인터넷과 연결 가능한 기기만 있다면 어디서든 외국의 영상매체를 시청할 수 있게 되었다. Netflix와 Youtube는 대표적인 영상 플랫폼이고 많은 사람들이 이용하고 있기도 하다. 그러다보니 외국어를 알지 못하는 경우, 전적으로 자막에 의존할 수밖에 없다. 이에 본 연구에서는 두 개의 인기 플랫폼에서 양질의 번역을 제공하고 있는지 알아보기 위해 두 곳에서 동시에 상영하고 있는 영화를 골라 한국어 번역본을 가지고 비교해보고 더 나은 방향과 문제점을 도출하였다. 그 결과, 좋은 번역이란 번역가가 시청자들이 집중을 할 수 있게 적절한 생략과 자세한 설명을 한정된 시간과 공간 안에 할 수 있어야 한다. 작업물을 심도 있게 연구하고 충분한 시간을 들여 작업에 임한다면 번역의 퀼리티는 확연히 올라갈 것이다. 마지막으로 본 연구는 영상번역에 대한 가이드라인 없이 싼 단가에 최소한의 시간을 들여 제작한 영상물들의 오역을 통해 아직 과거에 머물고 있는 영상번역 시장 활성화에 기여하였다.

• Structural Engineering and Mechanics
• /
• 제77권4호
• /
• pp.441-461
• /
• 2021

Reinforced concrete (RC) columns are crucial in building structures and they are of higher vulnerability to terrorist threat than any other structural elements. Thus it is of great interest and necessity to achieve a comprehensive understanding of the possible responses of RC columns when exposed to high intensive blast loads. The primary objective of this study is to derive analytical formulas to assess vulnerability of RC columns using an advanced numerical modelling approach. This investigation is necessary as the effect of blast loads would be minimal to the RC structure if the explosive charge is located at the safe standoff distance from the main columns in the building and therefore minimizes the chance of disastrous collapse of the RC columns. In the current research, finite element model is developed for RC columns using LS-DYNA program that includes a comprehensive discussion of the material models, element formulation, boundary condition and loading methods. Numerical model is validated to aid in the study of RC column testing against the explosion field test results. Residual capacity of RC column is selected as damage criteria. Intensive investigations using Arbitrary Lagrangian Eulerian (ALE) methodology are then implemented to evaluate the influence of scaled distance, column dimension, concrete and steel reinforcement properties and axial load index on the vulnerability of RC columns. The generated empirical formulae can be used by the designers to predict a damage degree of new column design when consider explosive loads. With an extensive knowledge on the vulnerability assessment of RC structures under blast explosion, advancement to the convention design of structural elements can be achieved to improve the column survivability, while reducing the lethality of explosive attack and in turn providing a safer environment for the public.

• 마이크로전자및패키징학회지
• /
• 제29권1호
• /
• pp.43-47
• /
• 2022

본 연구에서는 보일러 등에 적용을 하기 위하여 물속에 담군 채 가열할 수 있는 친환경 박막형 히터에 대한 결과를 보고한다. 장수명을 확보하기 위하여 소재 안정성이 높은 Mo 박막(40 nm)을 마그네트론 스퍼터법을 이용하여 Glass 기판상에 증착하였으며 후속 공정 진행 시 Mo 박막의 부식을 방지하기 위하여 상부에 ZnO 박막 (60 nm)을 형성하였다. 이후 투명 접착성을 가지는 PVB (Polyvinyl Butyral)를 이용하여 ZnO 박막 상부에 또 다른 Glass기판을 올려두고 열풍건조기 내에서 150℃의 온도에서 2시간동안 PVB를 경화시키며 접착시켜 Glass/Mo/ZnO/Glass 구조의 수중 히터를 완성하였다. 이렇게 제작한 발열체를 수중에 담근 후 발열 시 물의 온도가 2분 내 50℃까지 상승되는 것을 확인하였으며 미미한 수준의 저항증가가 발생하며 구조적 안정성 또한 확보되었다. 인가 전압의 세기에 따라 발열체의 온도가 제어되기 때문에 보일러에 적용할 때 사용자가 설정하는 온도를 용이하게 제어할 수 있을 것이라 기대된다. 마지막으로, 본 연구에서 제작한 박막형 히터는 반투명의 특성을 가져 심미성을 부여할 수 있어 제품의 부가가치를 더욱 높일 수 있을 것으로 기대된다.

• Journal of Microbiology and Biotechnology
• /
• 제32권1호
• /
• pp.46-55
• /
• 2022

Clostridioides difficile infection (CDI) is a significant cause of hospital-acquired and antibiotic-mediated intestinal diseases and is a growing global public health concern. Overuse of antibiotics and their effect on normal intestinal flora has increased the incidence and severity of infections. Thus, the development of new, effective, and safe treatment options is a high priority. Here, we report a new probiotic strain, Bacillus amyloliquefaciens (BA PMC-80), and its in vitro/in vivo anti-C. difficile effect as a prospective novel candidate for replacing conventional antibiotics. BA PMC-80 showed a significant anti-C. difficile effect in coculture assay, and its cell-free supernatant (CFS) also exhibited a considerable anti-C. difficile effect with an 89.06 ㎍/ml 50% minimal inhibitory concentration (MIC) in broth microdilution assay. The CFS was stable and equally functional under different pHs, heat, and proteinase treatments. It also exhibited a high sensitivity against current antibiotics and no toxicity in subchronic toxicity testing in hamsters. Finally, BA PMC-80 showed a moderate effect in a hamster CDI model with reduced infection severity and delayed death. However, further studies are required to optimize the treatment condition of the hamster CDI model for better efficacy and identify the antimicrobial compound produced by BA PMC-80.

• Journal of Dental Anesthesia and Pain Medicine
• /
• 제22권6호
• /
• pp.405-417
• /
• 2022

Oral lichen planus (OLP) is a chronic inflammatory immune-mediated condition that has been identified as a potentially malignant oral disorder. Various therapies have been proposed for its management as alternative to corticosteroids. However, no definitive treatment has been identified that can result in complete remission or minimal recurrence. Hyaluronic acid has recently been used as an alternative therapy for the management of OLP. This study aimed to systematically review the effectiveness of Hyaluronic acid in the management of symptomatic OLP. Online electronic databases and manual searches were performed for randomized controlled trials (RCTs) published in English between January 2010 and April 2022. RCTs were identified that compared the efficacy of hyaluronic acid and other interventional therapies at baseline and during follow-up. The Cochrane Risk of Bias tool was used to assess the quality of the included studies. Visual analog scale (VAS) scores, Thongprasom sign scores, lesion size, degree of erythema, clinical severity, and disease severity were assessed both quantitatively and qualitatively. Seven studies were analyzed. Five studies reported a high risk of bias while the remaining two studies reported an unclear risk of bias. The overall quantitative assessment of size, symptoms, degree of erythema, and sign score in OLP lesions treated with HA was not statistically significant compared to that in the control group (P > 0.05). In addition, subgroup analysis comparing HA with placebo or corticosteroids did not yield statistically significant (P > 0.05) results. Qualitatively, both HA and tacrolimus resulted in an effective reduction in signs and symptoms. Clinical/disease severity index/scores were inconsistent. A high degree of heterogeneity was observed among the included studies. None of the included studies reported the side effects of HA. These findings suggest that corticosteroids, tacrolimus, placebo, and HA could be equally effective in OLP management. The clinical/disease severity index or score reduction cannot be determined with certainty. Thus, OLP can be treated with HA as an alternative therapy. Owing to limited clinical trials on HA, high heterogeneity, and high risk of bias in the included studies, definitive conclusions cannot be derived.

• 한국농공학회논문집
• /
• 제64권6호
• /
• pp.43-53
• /
• 2022

Rice paddy has been actively converted into upland crop fields as more profitable upland crop cultivation are encouraged along with the decrease in rice consumption. However, the current water supply system remains mainly for paddy water supply, so research on pipeline water supply for upland cultivation is needed. The objective of this study was to optimize storage tank installation locations for pipeline water supply in reservoir irrigation districts. Five of reservoir irrigation districts were selected as the study sites and gridded of 10×10 m in size. Then genetic algorithm was adopted to evaluate the effects of spatial storage tank allocation on total pipeline cost. The lengths of the main and branch pipelines were considered as the objective cost function for the optimization of storage tank installation. Overall the shorter the branch pipeline and the longer the main pipeline, as the number of storage tanks increase. The minimal pipeline cost, i.e., optimal condition was reached when approximately 10% of the storage tank numbers to total upland plots were installed. The methodology presented in this study can be applied to determine the number and spatial arrangement of storage tanks for upland pipeline irrigation system design.