This study analyzed requirements for medical masks and difference in satisfaction based on demographic characteristics and side effects experience caused by wearing medical masks. Three factors related to requirements for medical masks were identified: wearing comfort and usability, blocking function for harmfulness, and design. As a result of the difference analysis for requirements of medical masks based on demographic characteristics, all three factors showed a significant difference in gender and occupation. Design did in age and monthly income. As a result of the presence or absence of breathing difficulties experience, design factor was significant. As a result of the presence or absence of skin trouble experience, wearing comfort and usability showed a significant difference. As a result of the difference in satisfaction with medical masks based on demographic characteristics and side effect experience caused by wearing medical masks, breathing, ear string tightness, blocking harmful substances, price, and over all wearing comfort showed a significant difference by gender, marital status, age, occupation, and monthly income, and the presence of absence of breathing difficulty experience and skin trouble experience, respectively. As a result of the interaction effect analysis between demographic characteristics and side effects experience caused by wearing medical masks, it showed a significant interaction effect between gender and monthly income, between marital status and monthly income, between monthly income and breathing difficulties experience, and between monthly income and skin trouble experience.

The decommissioning of nuclear facilities produces various types of radiologically contaminated waste. In addition, dismantlement activities, including cutting, packing, and clean-up at the facility site, result in secondary radioactive waste such as filters, resin, plastic, and clothing. Determining of the radionuclide content of this waste is an important step for the determination of a suitable management strategy including classification and disposal. In this work, we radiochemically characterized the radionuclide activities of filters used during the decommissioning of Korea Research Reactors (KRRs) 1 and 2. The results indicate that the filter samples contained mainly 3H (500–3,600 Bq·g−1), 14C (7.5–29 Bq·g−1), 55Fe (1.1– 7.1 Bq·g−1), 59Ni (0.60–1.0 Bq·g−1), 60Co (0.74–70 Bq·g−1), 63Ni (0.60–94 Bq·g−1), 90Sr (0.25–5.0 Bq·g−1), 137Cs (0.64–8.7 Bq·g−1), and 152Eu (0.19–2.9) Bq·g−1. In addition, the gross alpha radioactivity of the samples was measured to be between 0.32–1.1 Bq·g−1. The radionuclide concentrations were below the concentration limit stated in the low- and intermediatelevel waste acceptance criteria of the Nuclear Safety and Security Commission, and used for the disposal of the KRRs waste drums to a repository site.

Numerical modeling and scenario composition are needed to characterize the geological environment of the disposal site and analyze the long-term evolution of natural barriers. In this study, processes and features of the hydro-mechanical behavior of natural barriers were categorized and represented using the interrelation matrix proposed by SKB and Posiva. A hydro-mechanical coupled model was evaluated for analyzing stress field changes and fracture zone re-activation. The processes corresponding to long-term evolution and the hydro-mechanical mechanisms that may accompany critical processes were identified. Consequently, practical numerical methods could be considered for these geological engineering issues. A case study using a numerical method for the stability analysis of an underground disposal system was performed. Critical stress distribution regime problems were analyzed numerically by considering the strata’s movement. Another case focused on the equivalent continuum domain composition under the upscaling process in fractured rocks. Numerical methods and case studies were reviewed, confirming that an appropriate and optimized modeling technique is essential for studying the stress state and geological history of the Korean Peninsula. Considering the environments of potential disposal sites in Korea, selecting the optimal application method that effectively simulates fractured rocks should be prioritized.

Suncheon Bay Ecological Park, possessing abundant fisheries and biological diversity, was registered as a Ramsar wetland in Korea. Approximately 300 bacterial strains were isolated from the Suncheon Bay in a comprehensive study of indigenous prokaryotic species conducted during 2019-2020 in South Korea. A total of 12 bacterial strains were identified using 16S rRNA gene sequencing, demonstrating >98.7% sequence similarity with validly published species. These species were determined to be unrecorded bacterial species in Korea. A total of six strains were isolated from brackish water and Phragmites communis Trin (reed) species. These unrecorded species were phylogenetically diverse and belonged to three classes, six orders, and ten genera. Regarding the genus and class levels, the previously unrecorded species belonged to Jiella, Martelella, Rhizobium, Paracoccus, Rhodovulum, and Altererythrobacter of the class Alphaproteobacteria; Mycolicibacterium, Demequina, and Microbacterium of the class Actinobacteria; Confluentibacter of the class Flavobacteria. The twelve species were further characterized by gram staining, colony and cell morphology, biochemical properties, and phylogenetic position.

Recently, the necessity of designing and applying tool materials that perform machining of difficult-to-cut materials in a cryogenic treatment where demand is increasing. The objective of this study is to evaluate the performance of cryogenically treated WC-5 wt% NbC hard materials fabricated by a pulsed current activated sintering process. The densely consolidated specimens are cryogenically exposed to liquid nitrogen for 6, 12, and 24 h. All cryogenically treated samples exhibit compressive stress in the sintered body compared with the untreated sample. Furthermore, a change in the lattice constant leads to compressive stress in the specimens, which improves their mechanical performance. The cryogenically treated samples exhibit significant improvement in mechanical properties, with a 10.5 % increase in Vickers hardness and a 60 % decrease in the rupture strength compared with the untreated samples. However, deep cryogenic treatment of over 24 h deteriorates the mechanical properties indicating that excessive treatment causes tensile stress in the specimens. Therefore, the cryogenic treatment time should be controlled precisely to obtain mechanically enhanced hard materials.

COVID-19 감염은 전염성이 강한 RNA 바이러스 SARS-CoV-2에 의해 전 세계적인 건강 문제로 현재 대유 행 중이다. COVID-19는 호흡기 증상뿐만 아니라 다양한 신체적 증상이 발생한다. 신체의 거의 모든 기관에 영향 을 미칠 수 있으며, 눈에서도 다양한 증상을 보고하고 있다. SARS-CoV-2는 주로 사람 간 호흡기 비말 또는 에어로졸을 통해 사람에게서 사람으로 전염된다. SARS-CoV-2은 신체에 들어가 표면 지질 외피를 통해 돌출된 스파이크 당단백질을 사용하여 세포에 결합한다. SARS-CoV-2는 세포 표면 단백질 ACE2에 결합하여 바이러스가 세포를 감염시켜 눈에 손상을 준다. 결막염이 가 장 흔한 증상이며, 안구건조증, 이물감, 가려움증, 시력 흐려짐, 망막 출혈 등 눈의 증상은 매우 다양하다. 눈 자체는 전염 경로가 아닐 수 있지만, 전염 위험을 최소화하기 위해 눈을 보호하고 손 위생에 주의를 기울여야 한다. COVID-19에 감염되면 콘택트렌즈 사용을 중단할 것을 제안한다. 또한, 콘택트렌즈의 올바른 착용, 관리, 세척, 렌즈 및 렌즈케이스 교체 등을 통해 콘택트렌즈의 위생에 유의할 필요가 있으며, 일회용 콘택트렌즈를 권장한다.

Repetitive or excessive exposure to ultraviolet (UV) radiation causes oxidative stress-mediated skin photoaging through the overproduction of reactive oxygen species. Actinidia polygama is known as a medical plant used in oriental medicine for treating several diseases such as abdominal pain, stroke and rheumatoid arthritis. Recently, it was reported that A. polygama extract had anti-wrinkle and skin hydrating properties in ultraviolet B (UVB)-exposed hairless mice. However, the molecular biological mechanism of this extract on alleviating skin photoaging is still unknown. Therefore, we investigated the anti-photoaging effects of PB203, which is the powder of A. polygama extract, in the in vivo and in vitro photoaging models. First, PB203 showed 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activities due to the presence of anti-oxidant components including flavonoids and polyphenols. In UVB-irradiated hairless mice, oral administration of PB203 (100 mg/ kg) significantly improved wrinkle formation, skin dehydration, elasticity and skin barrier function by decreasing the levels of matrix metalloproteinases (MMPs) and increasing those of collagen I, filaggrin, involucrin and loricrin. Especially, the reduced production of p-p38, p-c-Jun and p-c-Fos by PB203 reversed the elevated levels of MMPs mediated by UVB exposure, resulting in the upregulation of collagen I expression. Consistent with these animal data, PB203 remarkably enhanced the mRNA expression of collagen I, filaggrin, involucrin and loricrin, while suppressed that of MMPs in UVB-irradiated HaCaT cells. And PB203 increased the wound recovery rate of cells by promoting their proliferation and migration. Moreover, PB203 significantly recovered the activity of superoxide dismutase inhibited by UVB in both mice and cells. In conclusion, PB203, which protects skin from UVB-induced photodamage by exerting antioxidant properties, can be considered to have sufficient potential as a functional ingredient or therapeutic agent improving skin photoaging and related skin symptoms.

Companies are making design changes by improving product quality and function to succeed while meeting customer requirements continuously. Design changes are changing the product BOM's amount, item, specification, and shape while causing a change in the product's structure. At this time, the problem of inventory exhaustion of parts before design change is a big topic. If the inventory exhaustion fails, the pieces before the design change become unused and are discarded, resulting in a decrease in asset value, and the quality cost of the design change affects the company's profits. Therefore, it is necessary to decide to minimize quality costs while minimizing waste inventory costs at the time of application of design changes. According to the analysis, priorities should be prioritized according to urgency because the quantity of items before the design change affects the applied lead time.

This study investigated the effects of complex problem-solving activities involving children’s literature on students’ critical thinking dispositions and English production. Thirty-one sixth-grade students were given lessons over a seven-week period. Various types of data were analyzed qualitatively, and the results of a critical thinking disposition test were analyzed quantitatively. Results were as follows: First, the critical thinking dispositions test revealed positive changes in open-mindedness, independence, objectivity, and inquisitiveness. The highest score was found for open-mindedness. The largest increase in score was for independence and objectivity. Second, changes in critical thinking dispositions enriched children’s English production. Open-mindedness helped with spoken language production as it encouraged students to share their opinions freely. Independence was mainly expressed in writing form in which students could question and evaluate the text. Greater objectivity was applied to spoken and written language production as the subjects were able to recognize the importance of evidence. Inquisitiveness affected children’s writing as it drove them to write down the results of their own research.

This study attempts a comparison between AHP(Analytic Hierarchy Process) in which the importance weight is structured by individual subjective values and regression model with importance weight based on statistical theory in determining the importance weight of casual model. The casual model is designed by for students’ satisfaction with university, and SERVQUAL modeling methodology is applied to derive factors affecting students’ satisfaction with university. By comparison of importance weights for regression model and AHP, the following characteristics are observed. 1) the lower the degree of satisfaction of the factor, the higher the importance weight of AHP, 2) the importance weight of AHP has tendency to decrease as the standard deviation(or p-value) increases. degree of decreases. the second sampling is conducted to double-check the above observations. This study empirically checks that the importance weight of AHP has a relationship with the mean and standard deviation(or p-value) of independence variables, but can not reveal how exactly the relationship is. Further research is needed to clarify the relationship with long-term perspective.

본 논문에서는 외계 행성에서 주어진 임무를 모두 수행하여 클리어하는 탑 뷰 슈팅 게임을 제안한다. 제안 하는 게임을 진행한 플레이어 45명의 로그 기록과 설문 조사 결과를 분석하여, 몰입감, 플레이 패턴의 다양 성, 접근성을 중심으로 제안하는 게임의 특징을 살펴보고자 한다. 첫째, 제안한 게임은 더 높은 몰입감을 위 해 스토리 애니메이션과 오디오를 제공한다. 실험 결과 시각, 청각적 방면으로 몰입감을 효과적으로 제공하 고 있어 대다수의 플레이어가 스토리 애니메이션을 건너뛰지 않고 끝까지 시청했다. 둘째, 제안하는 게임은 더 다양한 플레이 패턴으로 즐길 수 있다. 실험 결과 수많은 경우의 수가 존재하는 무기와 스킬을 선택할 수 있게 하였기 때문에 대부분의 플레이어가 선택하는 스킬들이 서로 겹치지 않고 다양한 방식으로 게임을 플레이할 수 있다. 플레이 패턴이 다양한 만큼 더 게임을 오랫동안, 더 재미있게 즐길 수 있다. 셋째, 제안한 게임은 맵을 비교적 단순하게 구성하였다. 그런데, 호기심 많은 일부 플레이어들이 미션과 직접 관련이 없는 경로를 찾아서 길을 헤매는 경우가 나타났다. 이로 인해, 플레이어들이 게임을 다시 한번 진행하고자 하는 경향이 나타났다.

The paint removal of fighter jets is just as important as the painting, because perfect paint removal ensures the quality of the exterior painting on the aircraft. However, the current conditions for paint removal work of the ROKAF’s are poor. It is identified that the painting process currently implemented by the ROKAF is not only exposed to harmful compounds such as harmful dust and hexavalent chromium, but also consumes a lot of water. Thus, the introduction of advanced facility is considered. This study compares the fighter jets painting removal process currently applied by the Korean Air Force with the improved laser coating removal process of the US Air Force, and conducts an incremental analysis to perform economic analysis for the introduction of advanced facility. Four scenarios were envisioned on the premise of an increase in the number of fighters in the future, incremental analysis shows that laser coating removal method is advantageous in all scenarios. In addition, it is recommended that paint removal cycle keeps the current 12-year and the outsourcing amount to civilian depot is reduced.

본 연구는 한국 푸드뱅크 사업의 발전에 대한 법제적 접근을 취하고 있다. 양적 성장에의 기여와 질적 성장에의 걸림돌이라는 상반된 평가를 받고 있는 <식품등 기부활성화에 관한 법률>에 관한 문제점을 분석 하고 이에 대한 개선방안을 제시하고자 한다. 이를 위해 기부식품등 제공사업의 특징과 한계를 살펴보고 <식품등 기부활성화에 관한 법률>의 정의, 기부식품제공사업, 식품등 기부활성화 시책, 국가지원, 실태조사 등에 대해서 심층적으로 검토한다. 연구결과를 토대로 본 연구는 한국의 푸드뱅크 사업의 발전을 위하여 법률적 관점에서 다섯 가지를 제안한다. 첫째, <식품등 기부활성화에 관한 법률>은 기부식품등 제공사업에 관한 별도의 장을 마련하여 법 체계성을 확보할 필요가 있다. 둘째, 기부식품등 제공사업과 기부자·사업자 에 대하여 명확하게 정의할 필요가 있다. 셋째, 임의신고제에서 비롯된 운영의 질 저하를 막기 위하여 신고 제를 개선할 필요가 있다. 넷째, 기초기부식품등지원센터의 지정제를 도입할 필요가 있다. 다섯째, 국가 차 원의 정기적인 실태조사 조항을 신설할 필요가 있다. 이 같은 법률적 개선이 이루어진다면 기부식품등 제공 사업의 공공성과 책임성, 투명성, 전문성이 한층 제고될 수 있을 것이다.

깨알벌레과는 전세계적으로 약 100속, 1,000여 종이 알려져 있다. 깨알벌레들은 다양한 서식처에서 채집되며, 깃털 모양의 날개와 작은 크기 로 쉽게 구분된다. 이 중 Acrotrichis속은 깨알벌레과의 약 4분의 1을 차지하나, 국내에서는 Acrotrichis lewisii (Matthews, 1884b)만이 2020년에 처음으로 기록되었다. 본 연구에서는 전국 농경지 생물상 변동조사 중 제주에서 채집된 A. thoracica (Waltl, 1838)와 A. grandicollis (Mannerheim, 1844)를 국내에 처음으로 보고한다. 이 두 종의 외형과 세부 사진, 분포도 그리고 한국산 Acrotrichis속의 분류키를 함께 제공한다.

최근 수십 년간 전 세계는 경제발전과 수송수단의 향상으로 다양한 외래종이 침입할 수 있는 시대가 되었다. 외국산 농산물의 수입요구는 외 래종의 침입을 보다 용이하게 하며 이렇게 침입한 외래종은 국내 생물상의 교란을 야기한다. 식물검역의 목적은 외래해충으로부터 국내 농업환경 및 생태계를 보호하는데 있다. 본 연구에서는 농림축산검역본부의 병해충정보시스템에 기록된 자료를 통해 1996년부터 2020년까지 수입절화류 에서 발견한 해충 검출 동향을 분석하였다. 이 기간동안 총 69개국 159품목 147,160개에서 검출된 해충은 13,757건의 467종 (잠정규제해충 273 종, 관리해충 78종, 비검역해충 118종)이었다. 특히, 총채벌레목과 매미목 해충의 검출율이 전체의 80% 이상을 차지하여 수입 절화류에서 가장 많 이 발견되는 해충분류군으로 분석하였다.

시금치의 주요 해충인 흰띠명나방(Spoladea recurvalis) 유충의 살충제 5종에 대한 감수성을 검정하였다. Lufenuron EC, chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, pyridalyl EW는 각각 2(12.5 ppm), 4(12.5 ppm), 8(2.5 ppm), 4(20.0 ppm), 8(12.5 ppm)배 의 희석농도에서 90% 이상의 높은 살충활성을 보였다. 추천농도로 경엽처리 후 7일이 경과된 시금치 잎에 흰띠명나방 유충이 72시간 동안 노출되 었을 경우 chromafenozide EC, chlorantraniliprole WP, tebufenozide WP, pyridalyl EW의 살충률은 각각 98.3%, 100%, 95.0%, 100%로 나타나 높은 잔효성을 보였다. 흰띠명나방에 대한 방제효과를 2개소(화성, 연천)에서 포장검정 결과, 5종의 약제 모두 2개소에서 약제처리 7일 경과 후 90% 이상의 방제효과를 보였으며 2배량에서도 약해가 없어 향후 흰띠명나방 방제약제로 시금치에 활용이 가능할 것으로 판단된다.