• Title/Summary/Keyword: refraction

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The Formal Innovation and Social Reflection of Korean Web Fiction Fantasy -Centered on 'Book Traveler' Genre (한국 웹소설 판타지의 형식적 갱신과 사회적 성찰 -책빙의물을 중심으로)

  • Yu, In-Hyeok
    • Journal of Popular Narrative
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    • v.26 no.1
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    • pp.77-102
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    • 2020
  • This article analyzes 'book traveler' stories as a new sub-genre of Korean fantasy web fiction. Formal innovation is revealed as the major motivation of Korean fantasy web fiction's narratives. Furthermore, the imagination of social resistance was presented as the formal devices of the genre. These theses were performed during the analysis of the two characteristics of the genre. In this genre, the main character is the writer or reader of fantasy stories. He moves into a novel he is describing or reading. The original novel, which was entered by the main character, is a space characterized by the custom of a typical fantasy genre. Therefore, the main character actually experiences cliché, typical genre devices and plots. The most important action for the main character here is to 'bend' the custom of the original. Therefore, this genre is in the form of the main motive being the refraction of typology. Meanwhile, the main character is not the central character of the original, but a secondary figure. The central character of the original book is usually from the ruling class, which monopolizes the good resources of society. At this time, the genre creates a subversive situation in which the social underdog goes beyond the social power through plots that overwhelm the central figure. It converts the reader's social desire into a genre device. To summarize, the latest trend in Korean web novel fantasy has captured scenes of renewed Korean genre literature practices. It sensitively reflects the social context of the contemporaries and the reader's desire. Thus, the Korean web novel fantasy has reflected both its internal conditions and its social context.

Crossplot Interpretation of Electrical Resistivity and Seismic Velocity Values for Mapping Weak Zones in Levees (제방의 취약구간 파악을 위한 전기비저항과 탄성파속도의 교차출력 해석)

  • Cho, Kyoung-Seo;Kim, Jeong-In;Kim, Jong-Woo;Kim, Ji-Soo
    • The Journal of Engineering Geology
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    • v.31 no.4
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    • pp.507-522
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    • 2021
  • Specific survey objectives often cannot be met using only one geophysical method, as each method's results are influenced by the specific physical properties of subsurface materials. In particular, areas susceptible to geological hazards require investigation using more than one method in order to reduce risks to life and property. Instead of analyzing the results from each method separately, this work develops a four-quadrant criterion for classifying areas of levees as safe or weak. The assessment is based on statistically determined thresholds of seismic velocity (P-wave velocity from seismic refraction and S-wave velocity from multichannel analysis of surface waves) and electrical resistivity. Thresholds are determined by subtracting the standard deviation from the mean during performance testing of this correlation technique applied to model data of four horizontal and inclined fracture zones. Compared with results from the crossplot of resistivity and P-wave velocity, crossplot analysis using resistivity and S-wave velocity data provides more reliable information on the soil type, ground stiffness, and lithological characteristics of the levee system. A loose and sandy zone (represented by low S-wave velocity and high resistivity) falling within the second quadrant is interpreted to be a weak zone. This interpretation is well supported by the N values from standard penetrating test for the central core.

Investigation of the Environment and Working Scope of Optometric Personnel in Ophthalmology (안과검안인력의 근무 환경 및 업무 범위에 관한 조사)

  • Han, Minho;Park, Junbeom;Jeon, Okhwan;Hwang, Eul Sung;Park, Hyun Jin;Lee, Min Woo;Kim, Gibong;Koo, Bon-Kyeong;An, Younghoi
    • Korean Journal of Clinical Laboratory Science
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    • v.54 no.3
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    • pp.224-238
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    • 2022
  • The environment and scope of work of optometric personnel in ophthalmology are unknown. We aimed to investigate these topics using an online survey. Based on the results obtained, we also make policy proposals from the perspective of clinical laboratory technologists to the University-Association-Academy. The age distribution of the study subjects was as follows; 20s (40.7%), 30s (28.4%), 40s (23.5%), and 50s (7.4%). Women constituted 56.0% of the cohort, and careers were evenly distributed from <1 to ≥15 years. We found optometric personnel had high levels of work-related stress, frequent occupational diseases, and that their duties were wide in scope. More manpower is needed to reduce work stress and improve work satisfaction. Clinical laboratory technologists held more senior positions at 48% compared to others and the occupational distribution was closely related to the senior occupation (P<0.001). Clinical laboratory technologists were responsible for about 30 types of eye examinations, and the most frequently performed examination was the refraction test; anomaloscopic examinations took the most time (27 minutes). Taken together, clinical laboratory technologists perform various eye exams. Given the importance of clinical laboratory technologists in optometry, a multifaceted effort is required at the University-Association-Academy.

Influence of Pile Driving-Induced Vibration on the Adjacent Slope (파일 항타진동이 인접 비탈면에 미치는 영향)

  • Kwak, Chang-Won
    • Journal of the Korean Geotechnical Society
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    • v.39 no.5
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    • pp.27-40
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    • 2023
  • A pile is a structural element that is used to transfer external loads from superstructures and has been widely utilized in construction fields all over the world. The method of installing a pile into the ground should be selected based on geotechnical conditions, location, site status, environmental factors, and construction costs, among others. It can be divided into two types: direct hammering and preboring. The direct hammering method installs a pile into the bearing layer, such as rock, using a few types of hammer, generating a considerable amount of pile driving-induced vibration. The vibration from pile driving influences adjacent structures and the ground; therefore, quantitatively investigating the effects of vibration is inevitably required. In this study, two-dimensional dynamic numerical modeling and analysis are performed using the finite difference method to investigate the influence on the adjacent slope, including temporary supporting system. Time-dependent loading induced by pile driving is estimated and used in the numerical analysis. Consequently, large surface displacement is estimated due to surface waves and less wave deflection, and refraction at the surface. The total displacement decreases with the increase of the distance from the source. However, lateral displacement at the top of the slope shows a larger value than vertical displacement, and the overall displacement tends to be concentrated near the face of the slope.

Accuracy of Astigmatic Correction Using Toric Intraocular Lens by Position and Size of Corneal Incision (각막절개 위치와 크기에 따른 난시교정인공수정체의 난시교정의 정확성)

  • Park, Wookyung;Kim, Man Soo;Kim, Eun Chul
    • Journal of The Korean Ophthalmological Society
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    • v.60 no.2
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    • pp.126-134
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    • 2019
  • Purpose: To assess the accuracy of toric intraocular lens (IOL) implantation by the location and size of the corneal incision. Methods: We retrospectively reviewed the medical records of 98 patients (98 eyes) who underwent phacoemulsification with toric IOL implantation from January 2014 to March 2017. The patients were divided into two groups: group 1 got an incision of the superior side of the cornea (n = 54) and group 2 received an incision on the temporal side of the eye (n = 44). For both groups, incisions were made at their steep corneal astigmatism axises. Each group was further divided into subgroups for whom different sized blades were employed (2.75 vs. 2.2 mm widths). We measured the refractive index and autokeratometric parameters. We postoperatively assessed residual astigmatism and any reduction thereof. Results: In both groups, uncorrected and best-corrected visual acuity, refraction cylinder astigmatism, and autokeratometric astigmatism improved statistically. Between two groups, corneal astigmatism decrease was not significant. Residual astigmatism also showed no significant differences between the two. Patients in both groups treated using 2.75 mm wide blades exhibited greater increases in corneal astigmatism. Conclusions: During cataract surgery, precise correction of astigmatism via toric IOL implantation is possible when surgically induced astigmatism is minimized by careful choice of the location and size of the corneal incision.

An Analysis on Conceptual Sequence and Representations of Eye Vision in Korean Science Textbooks and a Suggestion of Contents Construct Considering Conceptual Sequence in the Eye Vision (초 . 중등학교 과학 교과서에서의 시각(eye vision) 개념의 연계성과 표현 방식 분석 및 연계성을 고려한 시각 개념 구성의 한 가지 제안)

  • Kim, Young-Min
    • Journal of The Korean Association For Science Education
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    • v.27 no.5
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    • pp.456-464
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    • 2007
  • The aims of this research are to analyze the representations and conceptual sequence of eye vision in Korean science textbooks and to suggest a contents construct about eye vision where the conceptual sequence is considered. Research method was literature review, and the literatures that were used for analysis were the 7th Korean science curriculum which was revised in 1997, and the science and physics textbooks developed based on the 7th Korean science curriculum. The research results are as follows: 1) Although the science curriculum seems to have no problem on sequence in the eye vision concepts, the science and physics textbooks based on the curriculum reveal problems on the sequence in the eye vision concepts; 2) Some Korean science textbooks explain retinal image formation according to the Alhazen's idea, except in inverse image; 3) Some Korean science textbooks explain about the reasons of near- and far-sightedness without consistency between the textbooks for 7th and 8th grade students; 4) A few Korean science textbooks give an inappropriate explanation about the principle of eye sight correction by eye glasses; 5) According to the analysis result, the concepts related to eye vision should be presented in the order of explanation about light refraction phenomena, image formation process by convex lens, structure of human eye and retinal image formation process, correction of eye sight using lens.

Correlations between Higher-order Aberrations and Myopic Degree (근시도와 고위수차와의 상관관계)

  • Ryu, Nam-Yul;Kim, So Ra;Park, Mijung
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.2
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    • pp.199-206
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    • 2014
  • Purpose: The present study was aimed to investigate the correlation between higher-order aberration and myopic degree by the analysis of fluctuation of high-order aberration according to the change of myopic degree in certain ranges of myopia and astigmatism. Methods: The high-order aberration in a total of 992 eyes was analyzed by using a LADARWave device employing Hartmann-Shack system, and the relation between high-order aberration and myopia by the change of myopic degree through manifest refraction test. Results: In all subjects, spherical aberration and total coma aberration were significantly increased by the increase of myopic degree, however, trefoil aberration and astigmatic aberration and tetrafoil aberration were decreased. With the group of lower myopic degree, the change of coma aberration was greater by myopic degree and its change was significantly different. The change of spherical aberration by myopic degree was greatly large in the a group of -3.00 D or more and the group of -6.00 D or more where as its change was not large in the group of lower than -3.00 D. The significant decrease of coma aberration was observed only in the group of astigmatic degree of -1.00 D or less when analyzing the correlation between the higher-order aberrations and myopia in the certain groups of astigmatic degree. In the case of spherical aberration, the significant change was shown in all astigmatic groups, however, its increase was larger with the increase of myopic degree in lower degree of astigmatism. The consistent relationship in variations of horizontal and vertical coma aberration in certain myopic and astigmatic groups was neither established nor statistically significant. Conclusions: It is concluded that the correlation between the higher-order aberration and low-order aberration obtained from the results of the present study can help the understanding related to vision quality and the improvement of vision quality.

A Study for the Refractive Error on the Basis of Their Glasses Power (안경도수를 근거로 한 굴절이상에 관한 연구)

  • Jung, Han-Sub;Hong, Dong-Gyun;Park, Sang-An
    • Journal of Korean Ophthalmic Optics Society
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    • v.9 no.2
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    • pp.431-437
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    • 2004
  • This research reviewed the objects of 384 persons (male:86, female:298) from 6 to 50 years old visited the S. Optical shop at Mokpo over two times from Mar. 2002 to Feb. 2004. We obtained the following results by analyzing the visual acuity prescription to keeping at S. Optical shop. 1. The abnormal refraction eyes were 191 persons(49.74%) for simple myopia, 2 persons(0.52%) for myopic simple astigmatism, 180 persons(46.88%) for myopic compound astigmatism, and 1 person(0.26%) for simple hyperopia, 2 persons(0.52%) for hyperopic simple astigmatism, 8 persons(2.08%) for hyperopic compound astigmatism, respectively. 2. Classifying of correction power for 373 persons (male:84, female:289) myopia, so that showed 166 persons(male:36, female) between $$0.25D{\leq_-}2.00D$$, 194 persons(male:46, female:148) between $$2.25D{\leq_-}6.00D$$, 13 persons(male:2, female:11) for over 6.250 respectively. 3. According to the kinds of 192 persons astigmatism subjects(male:53, female:148), direct astigmatism was 145 persons(male:32, female:113), oblique astigmatism 33 persons (male:12, female:21), reverse astigmatism 14 persons(male:5, female:9). 4. The variation of spherical power for myopia showed 299 persons(male:71, female:228) between $$0.00D{\leq_-}0.50D$$, 64 persons(male:11, female:53) between $$0.51D{\leq_-}1.00D$$, 9 persons(male:2, female:7) between $$1.01D{\leq_-}1.50D$$, 1 person(male:0, female:1) between $$1.51D{\leq_-}2.00D$$ variation respectively. Hyperopia showed 8 persons(male:1, female:7) between $$0.00D{\leq_-}0.50D$$, 3 persons(male:1, female:2) between $$0.51D{\leq_-}1.00D$$ variation respectively. 5. The variation of astigmatism power showed 181 persons(male:48 female:113) between $$0.00D{\leq_-}0.25D$$, 25 persons(male:9, female:16) between $$0.26D{\leq_-}0.50D$$, 6 persons(male:0, female:6) between $$0.51D{\leq_-}0.75D$$ astigmatism variation respectively.

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Effect of Vision Training using Fresnel Prism Lens on Fusional Vergence and Accommodation (프레넬 프리즘렌즈를 이용한 시기능 훈련이 조절과 융합버전스에 미치는 영향)

  • Kim, Yong-Gil;Kim, Min-Kyung;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
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    • v.17 no.2
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    • pp.159-164
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    • 2012
  • Purpose: Of the various methods of vision training, the essay aims to explore the effective ways of using the Fresnel prism lens in order to expand the positive fusional vergence for the patient having specific condition of convergence insufficiency or basic exophoria. Methods: 15 students of city of Daejeon university without an eye disease (average age $22.73{\pm}1.68$) were selected and underwent the subjective refraction test and binocular vision test, and recording their test results before vision training and replacing an identical frame with a lens of same quality after the full calibration, the lens was then adhered with the Fresnel prism lens and continued to train for thirty minutes daily during two weeks. Afterwards, the binocular vision test was reattempted. The observation of the change in the results of the binocular vision test in use of the fresnel prism lens in the vision training test was researched. Results: After training, the positive fusional vergence had increased to a number of $22.27{\pm}2.26$ $\Delta$, to 7.80 $\Delta$, at near, the fused cross cylinder test increased to an average of $0.55{\pm}0.09$ D, 0.40 D after training, showing a normal result. The value of negative relative accommodation after training had an average of $2.22{\pm}0.08$D, showing that 0.42 D had increased. The value of near point of convergence after training had an average of $6.13{\pm}0.53$ cm, showing that 2.80 cm had decreased. To patients who had convergence insufficiency or basic exophoria, the value of the near vision test that used the Fresnel prism lens which was able to expand BO positive fusional vergence had increased without phoria. Conclusions: The changes were tested and the effectiveness of the Fresnel prism lens, due to the nature of the lens itself, helped with both cosmetic effects and cost. It also allows good optical correction effects, in addition to these clinical effects indicated before. Therefore, it may be determined that the Fresnel prism lens binocular vision therapy for patients is more popular and highly recommended.

Comparison and Analysis for the Effects of Functional Progressive Addition Lenses on Binocular Vision of University Students (기능성 누진가입도렌즈가 대학생들의 양안시기능에 미치는 영향 비교 분석)

  • Kim, Chang Jin;Kim, Hyun Jung;Kim, Jai-Min
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.1
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    • pp.105-116
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    • 2010
  • Purpose: To analyze and compare differences between single vision lenses and functional progressive addition lenses and improvement to binocular visual function wearing functional lenses for pre-presbyopes altered their single vision lenses to functional progressive addition lenses with low addition. Methods: Healthy 32 subjects aged 24.03${\pm}$1.87 (male 23, female 9) who were recruited from university students wore functional progressive addition lenses (EYE-T, Chemilens Co., Korea, ADD 0.750) for 2 months. Objective refraction, corrected visual acuity at distance and near, near point of convergence, near point of accommodation, accommodative facility, phoria at distance and near were measured. And subjective satisfaction was investigated by using a questionnaire designed to fatigue, comfort, discomfort, overall satisfaction and preference. Results: Functional progressive addition lenses were better than single vision lenses at near point of convergence and accommodation, accommodative facility. Exo phoria measured at distance with single vision and functional progressive addition lenses. Exo phoria measured at near with functional progressive addition lenses was higher than that with single vision lenses. As a survey, the satisfaction was increased in questions related near work. However, single vision lenses were preferred in distance test of overall satisfaction, easy 10 adapt, lime to adapt. A survey showed thai preference of functional progressive addition lenses were increased 75.00% to 81.26% for near work, 50.00% to 65.63% for visual fatigue, 47.75% to 50.00% for visual comfort and 31.25% to 46.88% for overall comfort. Conclusions: Comparing between single vision lenses and functional progressive addition lenses, binocular visual function related near work, subjective satisfaction and preference was improved after wearing functional progressive addition lenses. This study suggested that functional progressive addition lenses were useful for long time near work.