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        검색결과 9,893

        2221.
        2021.09 구독 인증기관 무료, 개인회원 유료
        We previously showed that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, in Bacillus subtilis acts as a virulence factor for osteoclastogenesis via the RANKL-dependent pathway. Hence, it can be hypothesized that GGT of periodontopathic bacteria acts as a virulence factor in bone destruction. Because Fusobacterium nucleatum, which is a periodontopathic pathogen, has GGT with a primary structure similar to that of B. subtilis GGT (37.7% identify), the bone-resorbing activity of F. nucleatum GGT was examined here. Recombinant GGT (rGGT) of F. nucleatum was expressed in Escherichia coli and purified using the His tag of rGGT. F. nucleatum rGGT (Fn rGGT) was expressed as a precursor of GGT, and then processed to a heavy subunit and a light subunit, which is characteristic of general GGTs, including the human and B. subtilis enzymes. Osteoclastogenesis was achieved in a co-culture system of mouse calvaria-derived osteoblasts and bone marrow cells. Fn rGGT induced osteoclastogenesis to a level similar to that of B. subtilis rGGT; furthermore, osteoclastogenesis was induced in a dose-dependent manner. These results suggest that F. nucleatum GGT possesses a virulent bone-resorbing activity, which could play an important role in the pathogenesis of periodontitis.
        4,000원
        2222.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        RPG는 다양한 게임요소의 구성을 통해 게임플레이의 재미와 플레이 목적을 제공한다. 이중 던전은 유저가 게임을 플레이하는 장소로써의 역할과 함께 퍼즐들의 요소가 추가되어서 하나의 난관으로서의 역할도 수행 하고 있다. 기존의 RPG의 던전은 숙달과정을 반복하게 되면 더 이상 퍼즐요소와 게임의 난관 요소로 작용 할 수 없게 되며 하나의 통로와 공간으로의 역할로 축소하게 된다. 본 연구에서는 RPG를 구성하고 있는 던 전의 수명과 게임요소로써의 역할을 증대시키기 위해 서스펜스 요소를 도입한 던전을 연구하였다. 서스펜스 의 요소를 통해 유저에게 지속적으로 긴장감을 부여하고 단순한 통로로써의 역할이 아닌 게임의 공략요소 로써 던전이 사용될 수 있도록 한다. 특히, 서스펜스 요소의 조합을 바탕으로 던전 구성에 지속적인 변화를 추가하여 같은 던전을 공략할 때도 새로운 경험을 겪을 수 있게 하여 지루함을 탈피하고 플로우를 경험하 는 만족도 높은 던전을 구성할 수가 있다.
        4,200원
        2223.
        2021.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The use of humor has been a controversial research topic in language classrooms. Humor is pervasive; however, the functions of humor in primary English-as-a-foreign-language (EFL) classrooms is under-investigated. To analyze the distinct features of humor, this study explores the specific functions of humor in primary English teaching classrooms in South Korea. The data set included thirty 40-minute English lessons videotaped in 2019 and semi-structured interviews with three teachers. Data were analyzed by identifying humor sequences, transcribing these classroom sessions and interviews, coding recurrent themes, and sorting representative excerpts. As a result, psychological, social, and behavioral functions of humor were conceptualized. The findings showed that humor (i) mitigated learners’ anxiety and aroused interest in language learning, (ii) reinforced constructive teacher-learner relationships and enabled camaraderie between learners, and (iii) regulated student behavior or rationalized learners’ listening incomprehension. Pedagogical implications are also discussed regarding ways to use and respond to humor in language classrooms.
        6,000원
        2224.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Helicobacter (H.) pylori is one of the most common pathogenic bacteria in the human gut, and is also one of the most important factors that cause digestive disorders such as chronic inflammation, gastric ulcers, and even gastric cancer. Since the use of various antibiotics to treat H. pylori infection is associated with the development of resistance in this bacterium, the aim of this study was to determine the anti-H. pylori effects of Peucedanum japonicum extracts (PJE) in the stomach tissue of C57BL/6 mice. In this experimental study, 50 C57BL/6 mice in five groups were evaluated. After induction of H. pylori infection in mice with the standard strain of H. pylori (ATCC 43504), the infected mice were treated with 3 different doses of PJE in different groups. Then, the anti-H. pylori effects of PJE were evaluated by rapid urease test (CLO), histopathological exam and blood interleukin (IL)-8 ELISA analysis. Based on CLO results, H. pylori eradication effects of PJE was observed. H. pylori infection of C57BL/6 mice showed significant increase of histopathological lesion scores. However, the treatment of PJE showed significant decrease of histopathological lesion scores. The treatment of PJE decreased gastric inflammation and mucosal lesions in the stomach of H. pylori-infected mice. Blood IL-8 levels were elevated 4 weeks after H. pylori inoculation. However, the treatment of PJE showed significant decrease of IL-8 level. According to the results of this study, PJE could be useful in the reduction of H. pylori infection in the mouse model.
        4,000원
        2225.
        2021.09 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        C-reactive protein (CRP) is an acute-phase protein produced by hepatocytes. The plasma concentration of CRP peaks around 48 hours following stimulation. A rapid decrease in CRP levels is observed when the stimuli end. Considering these characteristics of CRP, it is used to evaluate acute inflammatory responses in clinics. In addition, as it reflects the degree of surgical trauma, measuring the CRP concentration is an effective method of evaluating tissue damage depending upon the surgical method. As CRP is also an acute-phase protein in dogs, the purpose of the present study was to compare the factors related to acute inflammatory responses between dogs undergoing elective general surgery (GS) and orthopedic surgery (OS). A total of 44 healthy dogs were included in this study. The sex ratio of dogs that underwent OS was similar. Both groups showed increased CRP levels and white blood cell (WBC) counts on post-operative day (POD) 1-2. The CRP level in the OS group on POD 1-2 was significantly higher than that of the GS group and it was increased about 16-fold compared to the pre-operative value. No significant difference in WBC counts was observed between the two groups. Although a slight increase in the WBC count was observed on POD 1-2 in both groups, it was near the reference range during follow-up. Thus, measuring CRP levels can be more effective in evaluating acute inflammatory responses than WBC counts. Although a high level of post-operative serum CRP concentrations was observed in the OS group, it rapidly decreased to a level similar to the pre-operative value if there were no post-operative complications.
        4,000원
        2226.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the colon and rectum with intervals of acute exacerbation. Its etiology remains unknown, although recent studies suggest that pro-inflammatory cytokines initiate the inflammatory responses. In this study, we investigated the ameliorative effects of YB-21 (new product containining Lactobacillus plantarum, Barley Bran and Nymphaeaceae) in a dextran sulfate sodium (DSS)-induced colitis in mice. The experimental groups were divided into 6 groups (n = 10) of ICR mice: normal control(NC), DSS-treated(PC, positive control), DSS+latic-L-treated (3×107CFU/ml), DSS+latic-M-treated (3×109CFU/ml), DSS+latic-H-treated (3×1011CFU/ml), and DSS+YB-21-treated. Histological examinations indicated that YB-21 suppressed edema, mucosal damage, and the loss of crypts induced by DSS. Moreover, YB-21 reduced serum level expressions of, tumor necrosis factor-α (TNF-α). These results suggest that YB-21 has an anti-colitic effect by the suppression of intestinal inflammatory responses in DSS-induced colitis in mice.
        4,000원
        2227.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The sensory stimulation of a cosmetic product has been deemed to be an ancillary aspect until a decade ago. That point of view has drastically changed on different levels in just a decade. Nowadays cosmetic formulators should unavoidably meet the needs of consumers who want sensory satisfaction, although they do not have much time for new product development. The selection of new products from candidate products largely depend on the panel of human sensory experts. As new product development cycle time decreases, the formulators wanted to find systematic tools that are required to filter candidate products into a short list. Traditional statistical analysis on most physical property tests for the products including tribology tests and rheology tests, do not give any sound foundation for filtering candidate products. In this paper, we suggest a deep learning-based analysis method to identify hand cream products by raw electric signals from tribological sliding test. We compare the result of the deep learning-based method using raw data as input with the results of several machine learning-based analysis methods using manually extracted features as input. Among them, ResNet that is a deep learning model proved to be the best method to identify hand cream used in the test. According to our search in the scientific reported papers, this is the first attempt for predicting test cosmetic product with only raw time-series friction data without any manual feature extraction. Automatic product identification capability without manually extracted features can be used to narrow down the list of the newly developed candidate products.
        4,000원
        2228.
        2021.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        There is a growing research interest in language teachers’ professional identity. Nevertheless, unlike studies involving the identity of native and non-native English-speaking teachers, few studies analyzed Gyopo English teachers’ identity despite a sizeable body of Gyopo teachers in the Korean educational context. Using post-structural perspectives of identity, this case study analyzed the identities of a Gyopo instructor as an English teacher and how such identities were reflected in classroom practice. Data were collected through interviews, classroom observations, and self-reflective reports written by the participant. Findings reveal that the participant constructed multiple professional identities as a teacher with previous language learning experiences, a bridge-builder, a multitasker, and a teacher who is not a native English speaker but an American, and a replaceable person. While experiencing identity conflicts, she constantly negotiated and renegotiated her multiple, contradictory identities to position herself more favorably. Based on these findings, the present study offers pedagogical suggestions.
        6,900원
        2229.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this research is to examine the significance of peer-peer interactions on L1 discussions for L2 reading tasks. This research was designed to see how college EFL students interact during a L1 group discussion assigned as part of an L2 reading task by a means of CA (conversation analysis). Five college EFL students engaged in an L1 group discussion on L2 reading comprehension questions and their conversations were video-recorded for transcription. The peer-peer interaction CA analyzed discussions through a turn-taking system and contextualization cues and has provided pedagogical implications. Observed interactions among students showed that a team leader playing a role as a mediator attempted to focus on the issues arising during the discussion to solve and foster the engagement from other team members. The findings of this study suggest that students effectively find the best ways of reaching desirable conclusions through negotiation-driven interactions. Group discussions with L1 can encourage students to use their linguistic resources to perform the L2 task effectively, which leads to successful completion of the given tasks.
        6,000원
        2230.
        2021.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        To meet rapidly changing market demands, manufacturers strive to increase both of productivity and diversity at the same time. As a part of those effort, they are applying flexible manufacturing systems that produce multiple types and/or options of products at a single production line. This paper studies such flexible manufacturing system with multiple types of products, multiple Bernoulli reliability machines and dedicated buffers between them for each of product types. As one of the prevalent control policies, priority based policy is applied at each machines to select the product to be processed. To analyze such system and its performance measures exactly, Markov chain models are applied. Because it is too complex to define all relative transient and its probabilities for each state, an algorithm to update transient state probability are introduced. Based on the steady state probability, some performance measures such as production rate, WIP-based measures, blocking probability and starvation probability are derived. Some system properties are also addressed. There is a property of non-conservation of flow, which means the product ratio at the input flow is not conserved at the succeeding flows. In addition, it is also found that increased buffer capacity does not guarantee improved production rate in this system.
        4,200원
        2231.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The aim of this study was to analyze the semantic network structure of keywords and the visual composition of images extracted from Instagram in relation to the multipersona phenomenon with in fashion imagery, which has recently been attracting attention. To this end, the concept of a ‘secondary character’, which forms a separate identity from a ‘main character’ on various social media platforms as well as on the airwaves, was considered as the spread of multi-persona and #SecondaryCharacter on Instagram was investigated. 3,801 keywords were collected after crawling the data using Python and morphological analysis was undertaken using KoNLP. The semantic network structure was then examined by conducting a CONCOR analysis using UCINET and Netdraw to determine the top 50 keywords. The results were then classified into a total of 6 clusters. In accordance with the meaning and context of the keywords included in each cluster, group names were assigned : virtual characters, relationship with the main character, hobbies, daily record, N-job person, media and marketing. Image analysis considered the technical, compositional, and social styles of the media based on Gillian Rose’s visual analysis method. The results determined that Instagram uses fashion images that virtualize one's face to produce multi-persona representation s that show various occupations, describe different types of hobbies, and depict situations pertaining to various social roles.
        4,500원
        2232.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The emergence of environmental and social issues has led to global discussions for the realization of sustainable development. The purpose of this study is to propose a method of sustainable fashion design using waste Hanbok, focusing on men's Hanbok with cultural values. The study utilizes literature research and fashion design development. From the literature study, reform was judged to be a higher concept encompassing reduction, recycling, and upcycling. Reduction is a design method through removal, and recycling design transforms from its original form into a completely different product. Upcycling design focuses on improvement and change in functionality. Accordingly, nine redesigns using men’s Hanbok were developed from which three were produced. Consequently, the reduction design demonstrated a small range of variation without changing the item, and cultural sustainability was confirmed through the design that removed the components and recombined the Hanbok. Second, recycling redesign can be reconstituted into a different item. Third, upcycling enables various designs through module assembly, which prolongs the lifespan of the product and confirms its value as a raw material for waste Hanbok. This study is meaningful in realizing sustainable fashion and suggesting practical measures for the sustainability of Korean traditional culture and creative fashion design planning.
        4,500원
        2233.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study analyzed the effects of consumer confusion on shopping fatigue and negative purchasing behaviors in an internet shopping environment. Further, the effects of shopping fatigue on negative purchasing behaviors were analyzed. The survey was conducted among consumers in their 20s and 40s in the Seoul metropolitan area who had experience of purchasing fashion products through internet shopping. A total of 392 questionnaire were analysis, with frequency, reliability, factor, correlation, and regression analysis completed using the SPSS statistics program. The results of the study showed that consumer confusion and shopping fatigue in internet shopping environment affected negative purchasing behaviors. First, consumer confusion comprised overload confusion, similarity confusion, and ambiguity confusion. It was found that overload confusion and similarity confusion significantly affected shopping fatigue. Second, shopping fatigue significantly affected negative purchasing behaviors, and an increased level of shopping fatigue result in, increased purchase delay and non-purchase behavior. Third, consumer confusion (overload confusion, similarity confusion, ambiguity confusion) significantly affected purchase delay behavior, while similarity confusion and ambiguity confusion significantly affected non-purchasing behavior. These results will provide useful data for e-CRM and marketing directions of internet companies and will contribute to rational decision-making of internet consumers and improve the quality of consumer life.
        5,100원
        2234.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aimed to explore alignments among three curricula based on the contents of the university level curriculum. The 2015 revised curriculum, International Baccalaureate(IB), and Next Generation Science Standards(NGSS) were selected for this study, and a college textbook was analyzed to compare the curricula. As the age groups studying the curricular were different, we reorganized them according to school ages prior to conducting the study. The results of the analysis were: first, the contents of the 2015 revised curriculum did not sufficiently elaborate on the natural hazards related to humans, unlike the university level, IB PYP, and NGSS curricula. Third, there are different ways of introducing scientific vocabulary curricula, meaning that the number of scientific vocabularies in the 2015 revised curriculum was less than that in the IB, PYP, and NGSS.
        4,000원
        2235.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 국내 유통되는 액상 유제품에 함유된 17종의 과불화화합물 (PFCs) 함량에 대한 모니터링을 위해 수행되었다. 샘플을 액체-액체 추출을 통해 추출하고 LC-MS/ MS로 정량 분석하였다. 시중에 유통중인 98개의 액상 유제품 샘플에서 PFCs의 모니터링을 진행하였으며 그 결과, PFTeDA를 제외한 16종의 PFCs가 검출되었다. 총 PFCs의 함량은 0.9037 ng/mL로 액상 우유에서 가장 높았으며, PFPeA, PFDS, PFHxA도 액상우유에서 0.1 ng/mL 이상의 농도 수준을 보였다. 미국과 이탈리아에서 수행한 연구와 비교했을 때 PFOA와 PFOS의 잔류 패턴은 유사한 것으 로 나타났으며, 농도 수준은 0.1 ng/mL 미만이었다. 액상 유제품은 다양한 가공단계(살균, 혼합, 지방제거 등)를 거쳐 총 PFCs의 함량이 감소하는 것으로 보여지며, 특히 짧은 탄소 사슬을 가진 PFCs가 크게 감소하거나 검출되지 않았다. 이는 식품 안전에서 원료의 PFOS와 PFOA의 잔류정도가 중요하다는 것을 의미한다.
        4,000원
        2236.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, the layered structures of immiscible Fe and Cu metals were employed to investigate the interface evolution through solid-state mixing. The pure Fe and Cu powders were cold-consolidated by high-pressure torsion (HPT) to fabricate a layered Cu-Fe-Cu structure. The microstructural evolutions and flow of immiscible Fe and Cu metals were investigated following different iterations of HPT processing. The results indicate that the HPTprocessed sample following four iterations showed a sharp chemical boundary between the Fe and Cu layers. In addition, the Cu powders exhibited perfect consolidation through HPT processing. However, the Fe layer contained many microcracks. After 20 iterations of HPT, the shear strain generated by HPT produced interface instability, which caused the initial layered structure to disappear.
        4,000원
        2237.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        GF-AAS와 수은분석기를 이용하여 납, 비소, 카드뮴 및 수은의 회수율로 정확도를 측정한 결과 92.67-102.56% 범위에서 측정되었고, 정밀도를 측정한 결과 0.21-6.00 RSD%의 재현성을 보였으며, CODEX guideline에서 규정하는 범위에 적합하였다. 또한, FAPAS QC material을 검증결과, 회수율은 96.7-102.0%, 재현성은 0.33-4.93 RSD%로 우수한 결과를 나타냈다. 한약재 430건의 평균 Pb 함량은 254.9 μg/kg (N.D.-2,515.2)이었고, 평균 As 함량은 171.0 μg/kg (N.D.- 2,465.2)이었으며, 평균 Cd 함량은 99.2 μg/kg (N.D.-797.1), 평균 Hg 함량은 6.0 μg/kg (N.D.-83.6)이었다. 분석 결과 우리나라에 유통되는 한약재 20종은 식품의약품안전처에서 규정하는 한약재의 중금속 함량에 대한 허용기준 이내의 결과로 모두 안전한 수준의 한약재로 나타났다. 이를 토대로 한약 규격품 제조업소를 품질관리의 기준으로 하여 유통되기 직전의 가공 포장 과정에서의 한약재 중 납, 비소, 카드뮴 및 수은의 함량을 조사하여 한약재 내 중금속 함량 실태를 파악하고, 국민에게 안전하고 우수한 한약재를 공급하기 위한 기초자료로 활용할 수 있을 것으로 사료된다.
        4,000원
        2238.
        2021.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Hydrolyzed proteins have an advantage over intact proteins in terms of their rate of digestion and absorption. The high-pressure enzymatic extraction (HPE) method has been shown to improve the quality characteristics of hydrolysates from Protaetia brevitarsis seulensis (Kolbe) larvae (PBSL). This study investigated the effects of the HPE treatment period, a key candidate factor, on the quality characteristics of PBSL HPE hydrolysates. The hydrolysates were prepared by HPE for 0, 12, 18, 24, 30, and 36 h under optimized conditions—solid:solvent ratio (1:14 [w/v]), using complex proteases (Alcalase:Flavorzyme:Bromelain = 1:1:1, 4%), treatment temperature (50oC), and pressure level (100 MPa). All quality characteristics tended to be superior with longer HPE treatment periods, most of which had the highest values at 30 h, with no significant difference or a slight decrease after that. The quality characteristics of the PBSL HPE hydrolysates were improved by 1.3-1.7 times under conditions of optimal HPE treatment period.
        4,000원
        2239.
        2021.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        It is dicult for observers to conduct an optical alignment at an observatory without the assistance of an optical engineer if optomechanical parts are to be replaced at night. We present a prac- tical tilt correction method to obtain the optimal optical alignment condition using the symmetricity of optical aberrations of a wide- eld on-axis telescope at night. We conducted coarse tilt correction by visually examining the symmetry of two representative star shapes obtained at two guide chips facing each other, such as east{west or north{south pairs. After coarse correction, we observed four sets of small stamp images using four guide cameras located at each cardinal position by changing the focus positions in 10-m increments and passing through the optimum focus position in the range of 200 m. The standard deviation of each image, as a function of the focus position, was tted with a second-order polynomial function to derive the optimal focus position at each cardinal edge. We derived the tilt angles from the slopes converted by the distance and the focus position di erence between two paired guide chip combinations such as east{west and north{south. We used this method to collimate the on-axis wide- eld telescope KMTNet in Chile after replacing two old focus actuators. The total optical alignment time was less than 30 min. Our method is practical and straightforward for maintaining the optical performance of wide- eld telescopes such as KMTNet.
        4,000원
        2240.
        2021.08 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Due to growing concerns regarding the effectiveness of full-scale online education, this study investigated motivational regulation strategies employed by tertiary-level English as a foreign language (EFL) learners taking a writing course via Zoom. Using a mixed method, this study examined a dataset comprising questionnaire responses of 154 Korean students with two proficiency levels and subsequent semi-structured interviews. Findings showed that the learners with a high English proficiency level utilized the instructor’s feedback significantly more than those having a low proficiency level. The high proficiency group also appreciated the Zoom context and the university-wide policy of English-medium instruction (EMI) significantly better than the other group. Finally, correlation analysis revealed significant relationship between the students’ uses of motivational regulation strategies and their responses to the context-dependent factors. For example, the strategic choice of instructor feedback was positively related to their perception of EMI. These findings are discussed for effective online EFL writing instruction in the post-pandemic era.
        5,700원