Whisker-type magnesium hydroxide sulfate hydrate (5Mg(OH)2·MgSO4·3H2O, abbreviated 513 MHSH), is used in filler and flame-retardant composites based on its hydrate phase and its ability to undergo endothermic dehydration in fire conditions, respectively. In general, the length of whiskers is determined according to various synthetic conditions in a hydrothermal reaction with high temperature (~180oC). In this work, high-quality 513 MHSH whiskers are synthesized by controlling the concentration of the raw material in ambient conditions without high pressure. Particularly, the concentration of the starting material is closely related to the length, width, and purity of MHSH. In addition, a ceramic-coating system is adopted to enhance the mechanical properties and thermal stability of the MHSH whiskers. The physical properties of the silica-coated MHSH are characterized by an abrasion test, thermogravimetric analysis, and transmission electron microscopy.

목적 : 한국 초등학생의 안축장 분포를 조사하고, 오전과 오후 측정시간에 따른 안축장의 차이를 관찰하였다. 방법 : 단면연구로 서울지역에 거주하는 12~13세(평균 연령: 12.4±0.3세, 여: 17명)의 34명 34안을 대상으로 하였다. 부분결합간섭 측정계를 이용하여 안축장을 측정하였고, 굴절이상도는 개방형 자동굴절력계를 이용하였다. 일일 동안 4시간 간격으로 오전 9시와 오후 1시에 두 번 안축장을 측정하였다. 결과 : 성별에 따른 안축장의 차이는 없었다(AM: 남, 24.24±1.19 mm; 여, 24.04±0.94 mm, p=0.578, PM: 남, 24.29±1.13 mm, 여, 24.18±0.85 mm, p=0.750). 오전과 오후에 측정된 안축장은 유의한 양의 상관성을 보였다(r2=0.949, p<0.001). 안축장은 오전 9시(24.18±1.08 mm)와 오후 1시(24.25±1.00 mm)에 관찰되었다(p=0.709). 그러나 안축장의 차이는 0.07±0.34 mm로 통계적으로 유의한 차이는 없었다. 결론 : 안축장은 전반적으로 오전 보다 오후에 길게 측정 되었지만 측정시간에 따라 통계적으로 유의한 차이는 없었다.

Oilseed rape is known to crop having low nitrogen use efficiency (NUE) but requires high levels of N fertilizer. NUE is associated with N remobilization from source to sink organ, consequently affects seed yield. Remobilization of leaf N is also related to transport of C/N metabolites in phloem. However, interaction between seed yield and phloem transport was not fully documented. In response to seed yield, N and C metabolites and their transport into seed from bolting to pod filling stage investigated in two contrasting genotypes (Capitol and Pollen) cultivated under ample (HN) or limiting nitrate (LN) supply. Seed yield was significantly reduced in N limitation and its reduction rate was much lower in Capitol than in Pollen compared to HN treated plants. Amino acid and protein content was higher in Capitol than in Pollen at bolting stage. They gradually decreased during plant development but not significant between two cultivars and/or two treatments. Glucose, fructose and sucrose content were 1.8-,1.6- or 1.25-fold higher in LN condition than in HN condition, respectively. Amino acid and sucrose content in phloem were largely higher in Capitol than in Pollen under LN condition. These results indicate that the higher seed yield might be related to greater transport ability of amino acid and sucrose in phloem under LN condition.

The kidney is a highly complex organ, and acute or chronic renal diseases can occur with various complications such as diabetes and hypertension. So far, no target specific treatment is available in acute or chronic renal failure, necessitating the development of alternative therapeutic strategy. Recent experimental findings suggest that the renal function and structure can be restored after being treated with various sources of stem/progenitor cells. In this review, we discuss up-to-date findings of the potential of renal progenitor/stem cells in alleviating renal injuries with a focus on preclinical studies. We also review cellular mechanisms underlying the therapeutic function of these cells.

A simple and fast analytical method based on liquid chromatography-tandem mass spectrometry was developed for detection of the veterinary drugs acetanilide, anthranilic acid, antipyrine, cyproheptadine, diphenhydramine, DLmethylephedrine, and phenacetin in bovine milk. The target analytes were extracted from milk samples by using acetonitrile followed by clean-up with C18 and liquid-liquid purification with saturated n-hexane. A reverse-phase analytical column was employed with a mobile phase comprising (A) 0.1% formic acid in distilled water and (B) 0.1% formic acid in acetonitrile to achieve the best chromatographic separation. Matrix-matched calibration curves (r2 ≥ 0.9986) were constructed using six concentrations (1, 2, 5, 10, 20, and 40 μg/kg) of drugs in the milk matrix. Recoveries at three drug-spiking levels (5, 10, and 20 μg/kg) ranged from 71.2% to 103.8% with intra-day and inter-day relative standard deviation (RSD) values of ≤ 8.6%. The calculated limits of quantification (LOQ) were 0.19-7.1 μg/kg.

We present an analysis of the chemical abundances and kinematics of six low-mass dwarf stars, previously claimed to be candidate hypervelocity stars (HVSs). We obtained moderate-resolution ($R\sim6000$) spectra of these stars to estimate the abundances of several chemical elements (Mg, Si, Ca, Ti, Cr, Fe, and Ni), and derived their space velocities and orbital parameters using proper motions from the \gaia\ Data Release 2. All six stars are shown to be bound to the Milky Way, and in fact are not even considered high-velocity stars with respect to the Galactic rest frame. Nevertheless, we attempt to characterize their parent Galactic stellar components by simultaneously comparing their element abundance patterns and orbital parameters with those expected from various Galactic stellar components. We find that two of our program stars are typical disk stars. For four stars, even though their kinematic probabilistic membership assignment suggests membership in the Galactic disk, based on their distinct orbit l properties and chemical characteristics, we cannot rule out exotic origins as follows. Two stars may be runaway stars from the Galactic disk. One star has possibly been accreted from a disrupted dwarf galaxy or dynamically heated from a birthplace in the Galactic bulge. The last object may be either a runaway disk star or has been dynamically heated. Spectroscopic follow-up observations with higher resolution for these curious objects will provide a better understanding of their origin.

In this paper, two Korean textbooks that are most widely used in American colleges are analyzed for representations of gender, race and nationality. Literature review shows that representation in textbooks does matter for learners and that representations of gender, race, nationality, ethnicity, cultural diversities, disabilities, sexualities, non-nativeness, occupations, age, socioeducational backgrounds, etc. have been concerns of the researchers. While there have been a lot of studies on representations in EFL/ESL textbooks, such research on KFL/KSL textbooks is relatively new, even though representation is an important issue to the Korean language education in the era of globalization and multicultralism. The main characters who have names, conversations and illustrations and keep appearing throughout the analyzed textbooks are investigated. The main characters' number of appearances, firstness-the number of times to be presented first in exericses, examples or sentences-occasions, all speaking turns and I (initiation in the IRF sequence, Sinclair & Coulthard (1975))s are tallied, and it is explored if the numbers are relevant to the gender, nationality and race of the characters. Some analyzation of conversations and illustrations are also done for more discussion, which includes how KFL/KSL textbooks could be better in terms of representation.

This study investigated the prokinetic effect of metoclopramide and mirtazapine on gastric transit time (GTT), small bowel transit time (SBTT) and gastrointestinal transit time (GITT) during capsule endoscopy in four healthy beagle dogs. Four beagle dogs participated in the experiment as four groups at intervals of more than three days as the following: Control group 1 (capsule alone), Control group 2 (capsule alone), Metoclopramide administered group (metoclopramide + capsule) and Mirtazapine administered group (mirtazapine + capsule). The results of this study demonstrated there was no significant difference in GTT ([min] control group 1: 105 ± 90, control group 2: 172.5 ± 102 vs metoclopramide administered group: 247.5 ± 93, p = 0.07, 0.10) and SBTT ([min] control group 1: 120 ± 88, control group 2: 75 ± 39 vs metoclopramide administered group: 37.5 ± 15, p = 0.20, 0.18) for capsule only administered groups (control group 1 & 2) compared to metoclopramide administered group. In addition, there was no significant difference in GTT ([min] control group 1: 105 ± 90, control group 2: 172.5 ± 102 vs mirtazapine administered group: 127.5 ± 45, p = 0.56, 0.36) and SBTT ([min] control group 1: 120 ± 88, control group 2: 75 ± 39 vs mirtazapine administered group: 157.5 ± 38, p = 0.29, 0.07) between capsule only administered groups (control group 1 & 2) and mirtazapine administered group. In this study, the fact that metoclopramide might be ineffective and administration of mirtazapine might be inadequate in dogs were confirmed.

The occurrence of allergic disease has increased harmfully in the last few decades. Atopic dermatitis (AD) is an allergic inflammation disorder characterized by itchy, red, swollen, cracked skin. Although the pathogenesis of AD is not fully understood, it is assumed that deregulation of T-helper 1 (Th1) and T-helper 2 (Th2) immune responses, a predominance of allergen-specific IgE, and interrupted epidermal barrier function are keys to the pathogenic mechanism. Activated T helper 2 (Th2) immune function is hallmark of various allergic diseases. Oxidative stress implicated in cutaneous damage in various inflammatory skin diseases. We investigated the effect of fermented soybean (SCGB1) on the improvement of AD. Soybean fermentation was carried out using B. amyloliquefaciense SCGB1 (KCCM11964P), which is known to produce of natural antibiotics. And then, we experiment of SCGB1 and soybean powder (NC) in DNCB-induced AD model. Mice were respectively oral administration of variety dose for 14 days. As a results, it was confirmed that serum Immunoglobulin E (IgE) expression was dose-dependently decreased in SCGB1 and NC compared to negative control, and it was reduced the skin pruritus inducing factor that Interleukin-31 (IL-31) mRNA level. In addition, the inflammatory cells were infiltration in skin for histological analysis. As a result, it reduced that epidermal hyperplasia, cancellation and aveolarization compared to negative control. These results suggest that SCGB1 may be effective for prevention and treatment of AD.

This study examines multiple language-identities embedded within the emerging professional teacher identity of international graduate students teaching Korean as a foreign language (KFL). Situated in the context of Korean classrooms at an American university, this study draws data from two rounds of interviews with three instructors (one nonnative and two native Korean speakers). The qualitative analysis reveals that their professional teacher identity revolves around multiple language identities grounded in their L1 cultural norms and perceived English language proficiencies. Their views and undertakings of local cultural norms indicate the varying ways in which these instructors projected their L1 and L2 identities onto their emergent teacher identity. Given the vexed relationship between notions of teacher authority in her L1 Japanese culture and the local norms of interaction, the nonnative teacher maintained authority by establishing a certain distance from her students. By contrast, the native teachers accommodated the local understandings of teacher authority and (re)shaped their view of a teacher to the locally-defined professionalism, a teacher like ‘a friend’. The negotiated identity of the KFL teachers improved classroom interaction and engendered positive view about teaching. The findings are discussed to highlight foreign language teacher identity in a teacher education program.

본 연구에서는 블록체인의 본질에 입각한 바람직한 ‘블록체인 교육방안’을 제시하고자 ‘게이미피케이션’원리와 개념을 접목하고자 한다. 다른 영역에 게임의 요소를 적용시키는 신기술이 ‘게이미피케이션’이다. 본고는 게이미피케이션을 블록체인 교육 분야에 적용하였는데, 블록체인의 탈중앙화 및 참여자간의 합의와 수익배분의 개념은 게이미피케이션 이론의‘플레이어 경험(Player Experience, PX)’의 핵심원리와 상통하기에 의미있는 첫 번째 기초연구다. 본고에서는 국내외 블록체인 교육과정의 분석과 커리큘럼을 비교 분석하였다. MIT, UC Berkely UCLA, 등의 해외대학과 고려대, 서강대, 동국대 등의 Extension 및 석사과정 커리큘럼의 비교분석하였다. 현행의 기술교육위주의 블록체인 교육과정에 게이미피케이션 원리와 개념을 적용하여 효과적이고 바람직한 블록체인 교육방안 제안하였다. 이를 바탕으로, 블록체인 분야에 게임요소를 융합한 ‘블록체인 게이미피케이션’연구가 활발해져, 국내 게임 산업의 글로벌 경쟁력 향상에 도움이 되었으면 한다. 본 연구는 블록체인 게이미피케이션 융합기술을 바람직한 방향으로 안착시키기 위한 학문적 연구이자, 게이미피케이션 분야의 본격적인 산업화 촉진에 기여할 수 있었으면 한다.

Since South Korea started to operate MOOC service in 2015, the number of courses and registered students have greately increased every year. However, like the global MOOC, K-MOOC has also experienced problems in quality control in learning and completion rates, etc. As the various discussions about K-MOOC spread from the viewpoint of opportunity and challenges, researches related to academic papers have been increasing rapidly in recent years. At this point, this study aims to examine the research trends by integrating the academic researches published in Korea, and to analyze the research key words and contents highted in those researches. For the purpose of this study, a text-mining tool was selected to analyze the major research keywords and themes presented in the 83 published research journal articles. The findings revealed in the MOOCs literature of Korea can be summarized as follows. First, based on the result of frequency in research keywods, MOOC related research in Korea shows four themes: (a) higher education, including university and life-long education, (b) new model for online learning, e-learning and flipped learning, (c) analysis of characteristics in learning and learners(motivation, intention, interaction, safisfaction, etc). Second, the result of network analysis shows that MOOCrelated academic papers generally focused on analyzing the phenomenon appearing in the learning model of MOOC, rather than to capture the characteristics of K-MOOC itself. In addition, there are many practice-centered instrutional design studies that are applied to MOOCs in university(colledge) and adult education. Especially, flipped learning showed strong central degree in those papers. Based on these results, which mapped patterns and features of MOOC-related researches published in Korea, the present state of MOOC implementation and academic research is demonstrated, concluding with some implcations for future researach directions.

In spite of the benefits of English oral presentations on EFL learners' proficiency and competence, English presentations have not obtained much attention as instructional medium in the field of English education. With the belief that EFL learners' experience of English presentation performance can provide valuable insights for educators and researchers, this study intended to describe how EFL learners perceive their presentation performance through their reflective self-assessment. In particular, adopting Otoshi and Heffernen's (2008) rubric of evaluation, this study examined what a group of Korean EFL learners were concerned in regard to their presentation performances and how they evaluated them. The data collected were 41 reflective self-assessment papers written by 41 Korean college students. The papers were coded, categorized and interpreted. Findings showed that voice quality is the area the students in this paper were most concerned about. Negative evaluations of their presentation performance outweighed the positive evaluations except in the area of Power Point use. Lastly, rehearsal and visual aids education sessions as well as differentiating spoken and written English were suggested as instruction implications for educators.

본 논문은 보편적으로 복잡한 문제로 정의되던 테트리스 게임을 강화학습을 통해 해결하기 위한 아키텍처를 구현하였다. 테트리스 게임은 무작위로 나타나는 블록의 모양과 회전의 형태를 고려해서 블록을 최적의 위치에 신속하게 쌓아야 하므로, actor의 빠른 판단능력과 반응속도를 요구한다. 또한, 다양한 블록의 형태와 순서로 인해 매우 많은 경우의 수가 나타나기 때문에 수행의 주체가 사람이라면 단순히 기억력과 암기에 의존하는 방법으로는 수행에 한계가 있다. 따라서 본 연구에서 구현한 강화학습 아키텍처의 경우 학습 모델의 구현뿐 아니라 의사결정의 정확성을 높일 수 있는 휴리스틱을 보상에 가중치로 활용하는 방식으로 접목하였고, 그 결과 사람이 직접 게임을 수행하는 것에 비해 보편적으로 높은 점수를 얻을 수 있었다. 아직은 해당 분야를 완전히 정복하였다고 표현할 수는 없지만, 여러 번의 실험에서도 일반적인 사람에 비해서 더욱 좋은 플레이를 할 수 있었다. 하지만 성능에 가장 큰 영향을 미치는 요소가 학습 모델보다 휴리스틱에서 비롯되고 있다는 단점도 식별하였다. 이에 본 논문에서는 이러한 아키텍처의 구조와 사용한 기술들과 알고리즘에 대해 자세히 기술하였으며 접근 방향을 제시한다.

This paper compares the marine engineering courses of two maritime institutions: Mokpo National Maritime University of Korea in the East Asia region and Philippine Merchant Marine Academy in the Southeast Asia region. It shows examines educational marine engineering programs, along with the different divisions and courses at each college. It demonstrates a divergence in methodologies and course offerings to cultivate competitive graduates. The comparative assessment completed is intended to offer broader knowledge on how each institution tackles the requirements of the STCW, and to meet the present and future demands of the maritime industry. Different course offerings are compared along with the units and hours allocated to each subject, and the differences in marine engineering academic and training requirements to graduate. Students must satisfactorily earn 150 units to complete their choice of major. Statistical procedures were used in this assessment and analysis from Excel programs.