• 한국산학기술학회논문지
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• 제20권1호
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• pp.290-296
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• 2019

차량용 HUD는 자동차 전면 유리창에 안전 운전과 편의 운전 관련 다양한 정보를 표시해 주는 장치로 중요한 역할을 수행한다. 본 논문에서는 증강현실 기술에 적용이 가능한 대면적 비구면 자유형상 미러를 가공하기 위해 초정밀 가공기를 이용하여 가공을 실시하였고 그 결과를 측정하였다. 초정밀 다이아몬드 절삭은 정밀도가 높을 뿐만 아니라 표면 거칠기와 잔류 응력을 낮게 할 수 있어서 우수한 표면 무결성을 갖는 고급 부품의 생산에 유리하다. 또한 비구면 자유 형상의 몰드를 사용함으로써 광학 전달 함수의 개선, 왜곡 경로의 감소 및 특수 이미지 필드 곡률의 실현과 같은 장점을 얻을 수 있다. 이와 같은 비구면 자유형상 금형을 가공하기 위한 방법으로는 초정밀가공기를 이용한 다이아몬드 절삭 방법을 사용하였으며, 제작된 비구면 자유형상 미러 금형의 평가는 비구면 형상 측정기를 이용하여 실시하였다. 이러한 방법에 의해 $1{\mu}m$ 이하의 형상 정밀도(PV)와 $0.02{\mu}m$ 이하의 표면 거칠기(Ra)를 갖는 비구면 자유형상 금형을 제작할 수 있었다.

• Journal of Astronomy and Space Sciences
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• 제35권4호
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• pp.253-261
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• 2018

Korea Astronomy and Space Science Institute (KASI) has been developing the space optical and laser tracking (SOLT) system for space geodesy, space situational awareness, and Korean space missions. The SOLT system comprises satellite laser ranging (SLR), adaptive optics (AO), and debris laser tracking (DLT) systems, which share numerous subsystems, such as an optical telescope and tracking mount. It is designed to be capable of laser ranging up to geosynchronous Earth orbit satellites with a laser retro-reflector array, space objects imaging brighter than magnitude 10, and laser tracking low Earth orbit space debris of uncooperative targets. For the realization of multiple functions in a novel configuration, the SOLT system employs a switching mirror that is installed inside the telescope pedestal and feeds the beam path to each system. The SLR and AO systems have already been established at the Geochang station, whereas the DLT system is currently under development and the AO system is being prepared for testing. In this study, the design and development of the SOLT system are addressed and the SLR data quality is evaluated compared to the International Laser Ranging Service (ILRS) tracking stations in terms of single-shot ranging precision. The analysis results indicate that the SLR system has a good ranging performance, to a few millimeters precision. Therefore, it is expected that the SLR system will not only play an important role as a member of the ILRS tracking network, but also contribute to future Korean space missions.

• 한국산학기술학회논문지
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• 제19권11호
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• pp.332-337
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• 2018

항공기용 탐조등은 야간 임무 수행 시 탐색 또는 구조 임무에 사용되며, 은폐 상태를 유지하며 작전을 수행할 수 있도록 적외선 광을 제공한다. A기종 회전익 항공기 운용 중에, 적외선 생성을 위한 적외선 투과 필터 유리가 파손되는 현상이 다수 발생하였으며, 이로 인해 은폐능력이 상실되고 정비 소요가 발생하는 등의 문제점이 제기되었다. 본 논문에서는 해당 결함이 발생하는 탐조등의 운용 조건을 시험하고, 그에 따른 결함 원인을 도출한 과정을 기술하였다. 그리고 도출된 원인을 개선하기 위한 여러 가지 방안과 개선 필터 시제품 제작 과정을 정리하였다. 또한 개선된 필터가 장착된 탐조등에 대해 성능시험, 내구성 시험, 항공기 장착시험을 통해 탐조등의 규격에서 제시하는 성능 요구를 만족하는지 검증한 결과를 기술하였다. 시험 및 검증 결과 필터의 파손 현상이 개선되었으며, A 기종 항공기에 개선 필터를 적용한 결과 파손 현상이 더 이상 발생하지 않는 것을 확인하였다.

• Architectural research
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• 제21권3호
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• pp.79-90
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• 2019

The ephemeral and temporal nature of pavilions is the underlying motivation that led to the development of this paper. From the beginning of the industrial era through contemporary history, there have been many instances of architects attempting to rethink architectural design in the context of modern social, cultural, and technical imperatives. Today, the leading changes in humanity are accompanied by a revolutionary electronic digital medium. The pavilion has been in an amalgamation of architectural integration since the beginning of human history. World's Fairs/Expos have, since their establishment, served as international presentations of goods and achievements of particular nations. They became a popular stage wherein potential architectural achievements were showcased through the evocative architecture of pavilions. Due to the pavilion's "temporary nature," its coverage includes various perspectives: social, historical, geographical, post-colonial, iconographical, temporal, and ephemeral. It has also served as a receptacle due to its representational value at a given time. The pavilion has offered architectural designers, clients, and visitors a place to use their imaginations. Moreover, the architect's role in creating pavilions cannot be overestimated. Due to fact that they abound in symbolism, contemporary designs, and innovative solutions, pavilions often mirror modern mankind and plan for the next aesthetic revolutions and ideological architectural theories. To understand and appreciate architects' original intentions with their pavilions, this paper focuses on noteworthy pavilions that were created from the beginning of industrialization through the present. It explores and discusses the pavilion's characteristics, highlights the significance of its physical form as generated by a specific theme.

• 한국치위생학회지
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• 제19권5호
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• pp.665-676
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• 2019

Objectives: The purpose of the study was to analyze the association between indirect vision skills and neck, shoulder, and back pain in dental hygienists. Methods: This cross-sectional study included 85 dental hygienists working full-time at dental clinics. A survey was performed for musculoskeletal symptoms in the neck, shoulders, and back of the subjects. The O'Connor tweezer dexterity test was performed using a mirror to evaluate their indirect vision skills. For statistical analyses, the t-test and one-way analysis of variance were performed. Results: The neck was the most common region of musculoskeletal pain (89.4%). The most intense pain was experienced in the neck (70.6%) and right shoulder (60.0%). Neck pain (20.0%) caused the most interference with clinical practice. Indirect vision skills were lower in the group with severe pain in the left shoulder or with high interference in work due to the left shoulder pain (p=0.026 and p= 0.017, respectively) or right shoulder pain (p=0.004). Conclusions: In this study, neck pain was a major musculoskeletal symptom among dental hygienists, and poor indirect vision skills were associated with the development of shoulder pain. Therefore, to prevent such musculoskeletal symptoms, dental hygienists should become proficient in indirect visualization, which enables a balanced and neutral posture.

• Physical Therapy Rehabilitation Science
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• 제8권1호
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• pp.52-59
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• 2019

Objective: The purpose of this review was to investigate whether motor imagery training has an effect on the recovery of upper extremity function in individuals with hemiparetic stroke or not. Design: A systematic review and meta-analysis. Methods: PubMed and three other databases were searched up to December 18th, 2018 and randomized controlled trials (RCTs) evaluating motor imagery training on upper extremity function in persons with a diagnosis of hemiparetic stroke were included. This review selected the following information from each study: surname of the first author, published year, nation, population, intervention, therapeutic intensity of intervention, therapeutic comparison, outcome measures, additional therapy, summary of results, and descriptive statistics of outcome measures. Results: This review selected seventeen RCTs with 487 stroke survivors and the following intervention methods: six motor imagery training with additional therapeutic technology, two motor imagery training with additional modified constraint-induced therapy, four mirror therapy, and five motor imagery training. Ten RCTs were eligible for meta-analysis after systematic review. The motor imagery group were more effective than the control group based on the Fugl-Meyer assessment (3.43; 95% confidence interval [CI], 1.65 to 5.22; heterogeneity [$chi^2=8.03$, df=8, $I^2=0%$], test of overall effect Z=3.76; test for subgroup differences [$chi^2=2.56$, df=2, $I^2=21.8%$]) and the Action Research Arm Test (1.32; 95% CI, -8.12 to 10.76; heterogeneity [$Tau^2=70.74$, $chi^2=15.22$, df=3, $I^2=80%$], test of overall effect Z=3.76). Conclusions: The results of this review suggests that motor imagery shows positive effectiveness on improving upper extremity function in persons with hemiparetic stroke.

• Asian-Australasian Journal of Animal Sciences
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• 제32권7호
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• pp.1062-1068
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• 2019

Objective: For many generations, most species of farm animals have been subjected to intense and strictly targeted selection for improvement of their performance traits. This has led to substantial changes in animal anatomy and physiology, which resulted in considerable differences between the current animal breeds and their wild ancestors. The aim of the study was to determine whether there is breed-specific variability in behaviour as well as differences in emotional reactivity and preferences of laying hens. Methods: The investigations involved 50 Green-legged Partridge, 50 Polbar, and 50 Leghorn hens. All birds were kept in the same conditions, and the behavioural tests were carried out at 30 weeks of age. We used the tonic immobility test and a modified open-field test including such objects as water, commercial feed, feed enriched with cereal grains, finely cut straw, and insect larvae, a sandpit, a mirror, and a shelter imitating a hen nest. Results: The research results demonstrate that the birds of the analysed breeds differ not only in the excitability and emotional reactivity but, importantly, also in the preferences for environment-enriching elements. Ensuring hens' well-being should therefore be based on environmental modifications that will facilitate acquisition of essential elements of chickens' behaviour. The greatest emotional reactivity was found in the Leghorn breed, which may be a result of correlated selection aimed at an increase in chicken productivity. Conclusion: The differences in the behaviour of the birds from the analysed breeds indicate that laying hens cannot be regarded as one group of animals with the same environmental requirements.

• PNF and Movement
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• 제12권2호
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• pp.123-132
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• 2014

Purpose: The discovery of mirror neuron system may positively affect functional recovery; therefore, rehabilitation is needed that is practical for use in clinical settings. The purpose of this study was to examine the effect of action observation training on upper motor function in people who had suffered strokes. Methods: Three elderly patients with stroke, aged to years, were recruited from a stroke rehabilitation center. A nonconcurrent, multiple baseline subject approach was taken, with an A-B-A treatment single-subject experimental design, and the experiment was conducted for 3 weeks. The action observation training was repeated 5 times in 5 days during the intervention period. The arm function, including WMFT, BBT, and grip and pinch strength, was evaluated in each subject 5 times during the baseline period, the intervention period, and the baseline regression period. Results: The results of the evaluation for each subject were presented as mean values and video graphs. The WMFT scores of 2 subjects were improved during the intervention period in comparison with the baseline period, and this improvement was maintained even during the regression baseline period. The BBT and the grip and pinch strength were not improved. Conclusion: Based on these results, we suggest that the action observation training for 5 sessions was effective in improving upper limb function of stroke patients but was not effective in improving hand dexterity or grip and pinch strength.

• 영미문화
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• 제10권2호
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• pp.149-207
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• 2010

Written simultaneously with Prometheus Unbound, Shelley's "Julian & Maddalo" is a masterwork of dramatic poiesis, of doubling embedded in its couplets, dialogic debate on human nature and contrasted symbolic emblems. The emblems mirror each other and are themselves sites of generative paradox: the "heaven illumined" but "dreary tower" of the Maniac and the glorious sunsets on the "ever-shifting sand" of the Lido, a wasteland that is a place of self discovery but also of "abandonment" and barren mingling figured, inter alia, in its "amphibious weeds," a trope of the poem's personae. This essay also explores the poem's dramatic structure and various rhetorical devices, beginning with the Preface, a threshold of complex identity disguise that Shelley uses for veiled self-presentation, as in "Alastor," mirroring and literary references replete with nuanced ironies. I focus mainly on the complex figures of liminality Shelley uses to develop his own thoughts (as well as his ongoing debates with Byron) about man's potential for growth in thought, insight and empathy, in political reform and interpersonal and individual healing. Advancing Shelley's most optimistic ideas, Julian, escorted by Maddalo observes the Maniac, -- a living ruin whose pained eloquence reveals the link of eros to poiesis and the limits of the latter's ability to 'transform a world.' The Maniac is the core of muse-work (remembering, thinking and song) and Shelley presents him as its emblem. He also is prefigured in and reflects the quintessentially liminal Lido with its "barren embrace" of sea and land. Yet it is less the Maniac's feeling that his grief is "charactered in vain…on this unfeeling leaf" than Julian's rationales for leaving the site of pain that point to Shelley's final comment on poetry's transformative limits. As the primary haploids of the drama's meiosis re-combine and two of them, Maddalo and the maniac fall away, an analogy I briefly develop and embedded in the erotic dynamics of poiesis, Shelley suggests, as he did at the beginning of his poetic lyricism in "Alastor" and at its end in "the Triumph of Life"that images mislead and delude; that "the deep truth is imageless" and redemption is not in but beyond figuration.

• 영미문화
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• 제16권2호
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• pp.71-88
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• 2016

Cormac McCarthy's The Road depicts a post-apocalyptic future in which the time and reason of catastrophe are not specified, but it can be seen to project the contemporary social and ethical concerns in the dismal setting. In this respect, the journey the man and boy depart for to the South is on one hand a journey to seek a warmer place to support their lives in the literal sense and, on the other hand, a journey to seek 'what a human being is' in the devastated world in a metaphorical sense since they face extremely harsh and tremendously poignant conditions in which their creed as human beings is tested. This paper aims to explore the hazards of the current society that the text criticizes and the morality and ethical values to be preserved and pursued. The second chapter examines how the text describes the contemporary crisis through the dark and coldness of the land and its sterility. The land produces almost nothing as the entire surface was scorched and is now covered with thick ashes. It shows perfectly a destroyed and irrecoverably frozen land. Throughout this desolate and ruined land, the atrocity and violence of the survivors goes beyond the limit. Ravaging strangers and plundering villages are widely spread. These conditions mirror the apparent selfishness and immorality of the recent society. The third chapter analyzes the man's inconsistent or dualistic narrative on the good. He knows what the good is but doesn't allow the boy to demonstrate the good behavior on others. His conflict is rooted in his hope to protect his son from being attacked by others. Therefore it can be interpreted that the meaning and orders of living in this post-apocalyptic period are uncertain and indecisive. The fourth chapter examines the belief the man and the boy clings to. Unlike the man's contradictory decisions, he shows definite firmness to be 'the good' by not eating people and carrying 'the fire.' Until he dies, the man endeavors to protect his son and have him acquire the moral conviction and strength to carry the fire in the world. In conclusion, the text reads the current society critically and highlights the importance of the humanity that must not be discarded throughout the generations.