• Journal of the Korea Computer Graphics Society
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• v.26 no.3
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• pp.31-37
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• 2020

Identification of the mandibular canal path in Computed Tomography (CT) scans is important in dental implantology. Typically, prior to the implant planning, dentists find a sagittal plane where the mandibular canal path is maximally observed, to manually identify the mandibular canal. However, this is time-consuming and requires extensive experience. In this paper, we propose a deep-learning-based framework to detect the desired sagittal plane automatically. This is accomplished by utilizing two main techniques: 1) a modified version of the iterative transformation network (ITN) method for obtaining initial planes, and 2) a fine searching method based on a convolutional neural network (CNN) classifier for detecting the desirable sagittal plane. This combination of techniques facilitates accurate plane detection, which is a limitation of the stand-alone ITN method. We have tested on a number of CT datasets to demonstrate that the proposed method can achieve more satisfactory results compared to the ITN method. This allows dentists to identify the mandibular canal path efficiently, providing a foundation for future research into more efficient, automatic mandibular canal detection methods.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.91-100
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• 1989

This study was conducted to observe 1) the changes of cellular association in seminiferous tubles from 2 to 8 weeks of age, and 2) the cycle phenomena of seminiferous epithelia at 14 weeks of age in Japanese quail. Total 80 birds were examined at a week interval from 2 to 8 weeks, and 14 weeks of age. The results were summarized as follows： 1) The body and testis weights showed most prominent increase during 4 to 5 weeks and 6 to 8 weeks of age respectively. And also the diameters of seminiferous tubles were abruptly enlaged during 6 to 8 weeks of age. 2) Genocytes in the seminiferous tubles were still in existence at 3 weeks of age, however they did not come out after 4 weeks of age. Spermatogonia, primary spermatocytes and spermatids made their first arpearances in the seminiferous from 3, 4 and 6 weeks of age, respectively. Spermatozoa were observed for the first time at 7 weeks of age, but full spermatogenic activity was completed from 8 weeks of age. 3) At 14 weeks of age, the average weight at testis was 3.7g and its ratio to the body weight was approximately 3.0 percent. And at this age, average diameter of seminiferous tubules was 192.08 $\mu\textrm{m}$, and average numbers of spermatogonia, spermatocytes, spermatids and spermatozoa within the cross section of seminiferous tubules were 7.74, 40.81, 28.42, 104.55 and 105.98, respectively. Spermatogonia and spermatid were classfied into 2 and 3 types, respectively. 4) At 14 weeks of age, the cycle of seminiferous epithelium could be divided into S stages with following characteristics. (1) Stage I： Seminiferous tubules showing type I and II spermatids. (2) Stage II： Seminiferous tubules showing type III spermatids only. (3) Stage III： Immature spermatozoa gathered near the sertoli cytoplasm. (4) Stage IV： Forming a bundle of 15-20 spematozoa. (5) Stage V： Spermatozoa bundle leaving the sertoli cytoplasm into lumen of the seminferous tubule. 5) Usually 2-3 stages of the seminiferous epithelium cycle were concurrently appeared within a tubular cross section, and frequency of each stage from I to V within cross section of seminiferous tubules were 11.91%, 27.03%, 27.96%, 19.04% and 17.98%, respectively.

• Journal of The Korean Association For Science Education
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• v.34 no.5
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• pp.499-510
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• 2014

The purpose of this research is to understand interactive learning during docent-led tours in a science museum focusing on scaffolding. We developed a scaffolding framework by collating the work of other researchers in related fields. The results show that scaffolding included three dimensions: purpose, interaction, and domain. The purpose dimension, divided into six categories, is related to the intention of the scaffolder and what the scaffolding are for: strategic, social, procedural, conceptual, verbal, and metacognitive. The interaction dimension reflects students' interaction with the scaffolder in two ways: dynamic (situation specific) and static (planned in advance). The domain dimension is related to two contents: domain-general and domain-specific (such as science). The scaffolding framework was applied to dynamic interactions between docents and visitors. The data was collected from elementary school students' family visits with the guidance of two docents at the Seodaemun Museum of Natural History. The data collected consisted of surveys, interviews, video-recordings, and transcripts. The analysis shows that five guiding contexts and scaffolding phases were recognized; 1) strategic scaffolding in a poorly illustrated exhibit; 2) conceptual scaffolding in a thoroughly explanative exhibit; 3) verbal scaffolding in misleading interpretation; 4) procedural scaffolding in a manipulative exhibit; and 5) metacognitive scaffolding with inaccurate content. In addition, the results show that the docents used the dynamic and static scaffolding synthetically so that the docent-led tour was effective. In conclusion, this study presents the usefulness of understanding visitors' science learning through the scaffolding framework, as well as the how docents can scaffold actively.

• The korean journal of orthodontics
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• v.40 no.2
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• pp.66-76
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• 2010

Objective: Obstructive sleep apnea (OSA) is a common disorder which is characterized by a recurrence of entire or partial collapse of the pharyngeal airway during sleep. A given tidal volume must traverse the soft tissue tube structure of the upper airway, so the tendency for airway obstruction is influenced by the geometries of the duct and characteristics of the airflow in respect to fluid dynamics. Methods: Individualized 3D FEA models were reconstructed from pretreatment computerized tomogram images of three patients with obstructive sleep apnea. 3D computational fluid dynamics analysis was used to observe the effect of airway geometry on the flow velocity, negative pressure and pressure drop in the upper airway at an inspiration flow rate of 170, 200, and 230 ml/s per nostril. Results: In all 3 models, large airflow velocity and negative pressure were observed around the section of minimum area (SMA), the region which narrows around the velopharynx and oropharynx. The bigger the Out-A (outlet area)/ SMA-A (SMA area) ratio, the greater was the change in airflow velocity and negative pressure. Conclusions: Pressure drop meaning the difference between highest pressure at nostril and lowest pressure at SMA, is a good indicator for upper airway resistance which increased more as the airflow volume was increased.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.06b
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• pp.241-246
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• 2006

This paper describes two kinds of personal hand-held electronic devices to support marine leisure safety. The one is Radar response-type safety device triggering by the pulse signal from a commercial 9GHz-band Radar to provide quick search and rescue with combined civilian-government-military fleets. The other one is M-RFID (Marine Radio Frequency IDentification) based safety electronic device using 900MHz Tx/Rx with spread spectrum frequency hopping and GPS. Through the field tests at sea using Korea Coast Guard's warship the operating performances are verified. Further plan for practical use of each device was also discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.488-496
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• 1983

Narrow and broad sense heritabilities for the characters ranged from 0.1618 to 0.6914 and from 0.7494 to 0.9357, respectively, in F$_1$ hybrids of $5{\times}5$ full diallel crosses. Plant height and days to flowering had the highest heritabilities and yield and quality the lowest. Partial dominance was exhibited by plant height, number of leaves, leaf area per plant and days to flowering. Over dorminance was detected by leaf width and yield of cured leaf. Leaf length and quality would be considered being controlled by a complete dominance effect.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.608-611
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• 2003

선진국입을 목전에 둔 한국경제의 발전을 위해서 지식과 기술을 기반으로 한 벤처기업의 생성과 발전은 매우 중요한 요소라 할 수 있다. 민과 관의 적절한 벤처 투자는 미래의 기업가들에게 신지식 창조의 동기를 부여하고 성장, 발전단계에 있는 기업들에게 자본을 공급함으로써 미래의 산업을 창조하는 매우 중요한 활동이다. 국내외적으로 벤처 투자자본에 대한 연구가 활발히 진행되어 왔으나 재무론을 바탕으로 한 벤처투자에 관한 연구와 다양한 벤처투자자본들의 유형과 투자행태 등을 설문지를 통해 밝혀내는 탐색적 연구들에 국한되어 연구, 발표되고 있는 실정이다. 본 연구에서는 벤처자본시장의 대표적 투자자본인 사적 창업투자회사와 정부 벤처정책투자 간의 전략적 상호작용을 가격모델을 통해 고찰하였다. Bertrand paradox의 가정에서 기술한 바와 같이 정부 벤처정책투자간 민간 창업투자회사들과 같은 투자전략을 구사하면 민간 창업투자회사들은 시장에서 살아남기 어렵고 결과적으로 정부는 벤처기업의 생성 및 발전지원이라는 목적에 부합되지 않은 투자를 한 것이 된다. Hotelling(1929)의 위치차별모델이 역설하는 바와 같이 정부 벤처정책투자는 사적 창업투자회사가 지향하는 투자와는 다른 투자정책을 구사할 때만 벤처기업 육성이라는 목표를 효율적으로 수행할 수가 있을 것이다. 이 연구 논문에서는 다양한 투자변수에 대한 Nash Equibrium이 존재함을 증명함으로써 사적 창업투자회사와 정부의 벤처정책투자가 벤처기업의 육성이라는 목적에 맞는 효율적 투자를 하기 위해 취해야 할 투자 전략들을 밝혀내었다.가 있는 것 같다. 따라서 본 연구에서는 웹기반 쇼핑시스템의 확산에 관련된 균형된 분석을 수행하기 위하여 경영(management)과 기술 (technology)을 조화롭게 고려한 관점에서 연구를 수행하고자 한다. 즉, 본 논문에서는 기술적 측면(technical aspect)과 경영적 측면(management aspect)을 동시에 고려하여 웹기반 쇼핑시스템의 주요만 특성을 살펴보고, 향후 정보통신 기술(ICT)의 확산에 관한 연구에서 두 가지 관점의 통합적 중요성에 대하여 강조하고자 한다. 그에 덧붙여 웹기반 쇼핑시스템과 다른 정보시스템을 비교하여 전자상거래 환경에서 웹기반 쇼핑시스템의 주요만 특성들이 두가지 연구관점에서 어떻게 개념화 될 수 있는지를 고찰하고자 한다. 이러만 분석에 기반하여 본 연구에서는 기술적 측면과 경영적인 측면을 동시에 고려한 웹기반 쇼핑시스템의 특성을 제시하고자 한다. 결론적으로 본 연구의 목적은 본 논문에서 적용한 기술(technical)과 경영(management)의 조화로운 연구관점이 향후 정보통신 기술이나 시스템, 그리고 전자상거래에 관련된 일련의 연구에 적응되어 보다 균형잡힌 논의와 분석이 이루어 질 수 있는 시발점이 되길 기대한다.생된 $CH_{4}$를 회수하여 이용하면 대체에너지원으로 활용 가치가 높은 것으로 판단된다./207), $99.2\%$(238/240), $98.5\%$(133/135) 및 $100\%$ (313)였다. 각각 두 개의 요골동맥과 우내흉동맥에서 부

• Journal of Korean Philosophical Society
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• v.146
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• pp.49-77
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• 2018

This essay examines the ego (I-Subject) problem in Husserl's phenomenology and consists of four parts, as follows. Section I describes the meaning of this research on ego and some important points to note in relation to this study. Section II discusses two aspects of the problem of pure ego, which appears as an ego-problem for the first time. The first aspect is the two opposing positions that Husserl himself took regarding pure ego. Husserl initially rejected pure ego as an object of research in Logische Untersuchungen I (1901) however, he withdrew this position in Logische Untersuchungen II (1913). The second aspect is the content of pure ego that Husserl explored in Ideen I (1913) after he accepted pure ego as a phenomenological problem. The theme of section III is the "theory of three egos" which appeared in Ideen II (1912, 1952). Here, two issues have been noted, one of which is the methodological basis for enabling this theory: the phenomenological "attitude change" (Einstellungsaenderung) and the "Underlying" (Fundierung). The other is the explanation of the content of the three egos: the "physical ego", "personal ego" and the "pure ego". Section IV concerns two themes of the "monadic ego" that appeared in the Cartesianische Meditationen (1931). The first theme is the theoretical premise for the establishment of the monadic ego. In conjunction with this theme, phenomenological-psychological reduction was used as a new method to open up new problem horizons. The second theme brings up the content of the monadic ego, the essence of which can be summarized as follows. 1) This ego is based on a pluralistic and independent ego-concept in which each ego is equal to its own self. 2) It must be asked whether each of the monadic egos is different from one another. 3) The "other" of a certain transcendental ego is not the ego-other relationship but ego-another ego (alter-ego). 4) This phenomenological monadic ego can mutually communicate with alter-egos through empathy, unlike Leibniz's metaphysical monads.

• Applied Microscopy
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• v.37 no.1
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• pp.23-33
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• 2007

The lacrimal gland are compound tubule-acinar glands. The main lacrimal function is the production of the aqueous layer, the thickest and major constituent of the precorneal tear film. The lacrimal gland also has an important function in the defense system of the ocular surface, forming a part of the conjunctival-associated hymphoid tissue. The ultrastructural characteristics of the lacrimal gland of the rabbit were described. The lacrimal tissues of rabbits were processed through the conventional techniques for transmission electron microscopy. The secretory portions consisted of three cell types: 1. Serous cells with electron dense secretory granules. 2. Seromucous cells containing variable moderately electron dense secretory granules with flocculent material. 3. Mucous rolls containing mucous secretory granules. The serous cells were situated at the basal portion of acini, and they contained electron dense granules of variable densities and sizes. The seromucous cells contained a few protein secretory granules and more mucous secretory granules. The mucous cells contained even fewer protein secretory granules and exclusively mucous secretory granules. The epithelium of the intralobular ducts showed secretory granules, junctional complexes, and large basolateral intercellular spaces with lateral folds. These study might be helpful in determining inter-relationships, similarities and differences among the orbital glands of various physiological or pathological conditions.

• Korean Journal of Ichthyology
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• v.18 no.4
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• pp.311-318
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• 2006

Ultrastructure of germ cells, the cyst epithelial cells and interstitial cells during spermatogenesis of the stone flounder, Kareius bicoloratus (Pleuronectidae) sampled on the west coast of Korea were investigated by electron microscopic observations. In the primary spermatocyte, the synaptonemal complexes appear in the zygotene stage of the prophase during maturation division. In the growing testis, especially, the interstitial cells (Leydig cells) appear near the primary, secondary spermatocytes and spermatids. Well-developed interstitial cells (steroid hormone secreting cells) which are located in the interlobular space in growing testis have three morphological characteristics of a vesicular nucleus, mitochondria with tubular cristae and smooth endoplasmic reticulum. During spermatogenesis, the primary and secondary spermatocytes attach to the cyst epithelial cell (Sertoli cell) having an elongated ovoid or triangular nucleus and several mitochondria in the cytoplasm. In the growing testis, lipid droplets, the mitochondrial rosettes and glycogen particles appear in the cytoplasm of the cyst epithelial cells near the secondary spermatocytes and spermatids. Particularly, the mitochondria, endoplasmic reticulum, little lipid droplets and the large amount of glycogen particles are present in the cytoplasm of the cyst epithelial cell in the late growing testis. In the late stage of spermiogenesis, the proximal centriole is joined to the nuclear envelope, the distal centriole forms the basal body of the flagellum and gives rise to the axial filament of the flagellum. No acrosome of the sperm is formed as seen in other teleost fish. The head of the spermatozoon is approximately $3{\mu}m$ in length and its tail is about $30{\mu}m$ in length. The axoneme of the tail flagellum of the spermatozoon consists of nine outer doublet microtubules at the periphery and two centrial singlet microtubules at the center. The spermatozoon of this species has two axonemal lateral fins. Especially, the cyst epithelial cells which located near groups of gametes in the various stages, show three functions: nutrition, phagocytosis and steroidogenesis. Especially, the nuclei of cyst epithelial cells in the recovery stage of the testicular developmental stages appear to be irregular in shape after spermiation. Of three functions of the cyst epithelial cell, several characteristics of phagocytosis are showed in the cytoplasm of the cyst epithelial cells in the recovery stage of the testicular developmental stages. At this stage, therefore, it is assumed that the cyst epithelial cells are involved in degeneration and resorption of undischarged germ cells after spermiation.