• Journal of the Society of Naval Architects of Korea
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• v.47 no.4
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• pp.543-552
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• 2010

The Coanda effect is noticeable when a jet stream is applied tangential to a curved surface since then the jet stream remains attached to the surface beyond the point where flow separates otherwise and results in augmentation of circulation and lift. Numerous experimental and numerical studies have been performed in various fields of aerodynamics to exploit the Coanda effect and many of them found to be useful. It can be speculated that the Coanda effect may have practical application to the field of marine hydrodynamics as well since various control surfaces are being used to control behaviors of ships and offshore structures. In the present study, the Coanda effect has been applied to a horn type rudder and a series of numerical computations and model experiments are performed to find the practical applicability. The results indicate that the Coanda jet increases the lift coefficient of the rudder as much as 52% at the momentum coefficient $C_j$ = 0.1 and the rudder angle ${\alpha}=10^{\circ}$.

• Language and Information
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• v.19 no.1
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• pp.37-57
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• 2015

This paper is primarily intended to provide a new insight on which the structural properties of As-Parenthetical constructions shown by Potts (2002) might be regarded as cross-linguistically common one. As a first attempt, it introduces the characteristics of Korean As-Parenthetical by carefully investigating them through the data, focusing on the similarities or differences between two languages with a constructional theoretical perspective. The paper here provides three properties of Korean as-clauses in the morphological and syntactic aspects. First, the morpheme 'as' in English as-clause would be realized as three different morphemes as a bound one. Korean as-clauses can be introduced by three different morphemes, '-tusi, -chelem, -taylo' and unlike that in English as-clauses, they behave as bound morphemes which do not stand alone. Even though they are attached into different morpho-syntactic stems, they do not make any meaning change only under this clause. Secondly, two syntactic types of as-clauses can also be found in Korean, similarly to those of English: CP-As type and Predicate-As type, depending on which types of gap they involve in. English has one more subtype of Predicate-As type (called inverted Predicate-As clause), while Korean does not show this subtype. Thirdly, the various mismatches attributed by the gap and the antecedent come from the constructional restrictions of as-clauses in Korean. In addition, the paper attempts to display various ambiguities from the as-clauses through disjoint references or negative sentences in As-Parenthetical constructions.

• Journal of Ocean Engineering and Technology
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• v.29 no.4
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• pp.309-316
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• 2015

Lifting lugs are frequently used in shipyards to transport and turn over the blocks of ships and offshore structures. With the development of shipbuilding technology, blocks have increased in size, and block management technology has assumed a more important role in shipbuilding to enhance the productivity. For the sake of economics, as well as the safe design of a lug structure, a more rational design procedure based on a rigorous structural analysis is needed. This study investigated the strength characteristics of T-type lugs, considering the influence of blocks on which lugs are attached, by varying the in-plane and out-of-plane load direction. In this paper, the ultimate strength is also addressed for cases that include or do not include blocks in the strength analysis. In the present results, when there was a load acting in the normal direction to the block surface, the strength characteristics became poor, and the ultimate strength decreased. This paper ends by describing the need for further study to develop a more rational design for a lug structure.

• Journal of the Korean housing association
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• v.4 no.1
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• pp.47-55
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• 1993

The research was carried out by posing a questionnaire, making middle and high schoolstudents 549 in Taehu an object of this research, in order to grasp the residential outlook of juveniles.1. The first order of reason why they have resided in present their houses was by a school group and their parents' choice and work place and second order of reason was by their parents' choice, life convenience in present house add traffice convenience And there was littledifference in the first and second residential reasons according to sew.2. In compareson with past and present house type, past and present house type shewed same tendency and future wanted house type was separate house absolutely.3. Points to be considered in selectong future were in the order of facilities, traffice,, surrounding, educational, social and economical circumstances. There was little difference in almost items to be considered in choosing accordant to sew. But in case of schoolgirls, they consisered more items in selecting houses than in schoolboys.4. As a result of researching ideal house of juvenile, happy family was most Preferred and the desire to possess house was expressed strongly.5. The first value on house was health of family, the stability, the stabi]ity and the residential convenience. And schoolboys attacged more importance to the gealth of family, ghe stability and the education fer children than in case of school-girls but on the other hand school girls attached more importance to economical value house and happy and harmonious family.

• Journal of the Korean Institute of Rural Architecture
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• v.12 no.2
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• pp.135-142
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• 2010

This research aims to examine the characteristics of tomb sites including tomb mound and attached buildings and also to find out the principles reflected in the traditional oriental Feng-Shui location and spatial composition of Junkyung and Youngkyung tomb at Samcheok. The results of this study are as follows. These tombs harmonize with each other in the cosmic dual forces because Junkyung tomb is men's sex symbol and tiger to lie on his belly and Youngkyung tomb is women's sex symbol in geographical feature. Spatial structure in these tomb sites were placed in a reflected line following the hierarchy of metaphysics by standing high Geumchunkyo(Bridge)-Hongsalmun(Gate)-Jegak(Pavilion)-Bongbun(Tomb mound). Axis structure of these tombs is irregular bent-axis type from Geumchunkyo to Bongbun, specially in case of Youngkyung tomb it is getting more refractive. These tombs are divided into and characterized by three zones. Firstly the space for living people constitutes from Geumchunkyo to Hongsalmun, secondly the semi-sacred space constitutes from Hongsalmun to Jegak, and lastly the space for the dead constitutes from the back of Jegak to Bongbun. - type Jegak instead of T type Jegak generally used at Chosun Dynasty was installed because of claypan stretched out in front of Junkyung tomb and Bongbun of Youngkyung tomb located at a ravine between two mountain ranges.

• Journal of the Korean Society of Visualization
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• v.10 no.1
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• pp.15-20
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• 2012

PCV(Positive Crankcase Ventilation) system is designed to remove blowby gas. In this system, a PCV valve is attached in a manifold suction tube to control the flow rate of blowby gas which generates various operating conditions of an automotive engine. As this valve plays a crucial role, the demand in its design is high owing to the small size and high velocity. For this reason, a numerical investigation was carried out to understand both the spool dynamic motion and internal fluid flow characteristics. As a result, the spool dynamic characteristics(i.e. displacement, velocity, acting force), increase in direct proportion to the magnitude of the pressure difference and indicate periodic oscillating motions. Moreover, the velocity at the orifice region decreases according to the increase in differential pressure due to energy loss caused by the sudden decrease of flow area at the orifice region and the increase of flow volume in front of the spool head. Finally, the mass flow rate at the outlet decreases with the increase of spool displacement.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.12
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• pp.117-122
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• 2009

The hexagonal network-type PDMS microstructures were fabricated and they were employed to low-friction drag surfaces. While the lowest contact angle measured from the smooth surface was $108^{\circ}$ the highest contact angle measured from the microstructured surfaces was $145^{\circ}$ The moving speed of bullet-type capsule attached with a PDMS pad of smooth surface ($CA=108^{\circ}$) was 0.1261 m/s and that with a PDMS pad of microstructured surface ($CA=145^{\circ}$) was 0.1464 m/s. Compared with the smooth surface, the microstructured surface showed 16.1% higher moving speed. The network-type microstructures have a composite surface that is composed with air and PDMS solid. Therefore, the surface does not wet: rather water is lifted by the microstructures. Because of the composite surface, water shows slip-flow on the microstructures, and thus friction drag can be reduced.

• Journal of Species Research
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• v.9 no.3
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• pp.218-220
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• 2020

A holotype is an element to which the name of a taxon is permanently attached and is key material that facilitates taxonomic research. However, type citation or designation errors due to typographical errors or inadvertent mistakes often exist. When reviewing recently published literature for the type specimens of vascular plants in the herbarium of the National Institute of Biological Resources, we observed that three species, Isoetes laosiensis, Isoetes coreana, and Huperzia jejuensis, had errors, and the actual holotype information and the type descriptions of the protologues did not match. The name Isoetes laosiensis had a collecting number error, while Isoetes coreana and Huperzia jejuensis had collector errors. According to Article 9.2 of the International Code of Nomenclature for algae, fungi, and plants (Shenzhen code), if a holotype designation in the protologue of the name of a taxon is found to contain errors such as collector, collecting number, and illustration errors, the errors are to be corrected. We, therefore, corrected the errors in holotypes of three species, with no alterations made to the intents of the original authors.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.1360-1364
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• 2009

Necessity of removable soil nailing has been arisen in the soil nailing system because of problem such as civil petition for geotechnical environment and invasion of the ground boundary line and payments for use besides geotechnical engineering. Removable soil nailing system is improved soil nailing system that fixed socket arranged in boring hole for increasement of skin friction. In this study, field pull-out tests are carried out more 4 times considering installed distance of fixed socket and analyze skin friction behavior characteristics in fixed socket through analysis of measurements of strain gauge attached to fixed socket. Also, to evaluate application for wedge type removable soil nailing system analyzing displacement aspects through field pull-out tests by trial construction.

• Journal of Electrical Engineering and Technology
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• v.8 no.2
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• pp.376-384
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• 2013

With the continuous aging of the populations in developed countries, the medical requirements of the aged are expected to increase. In this paper, a ring-type pulse oximeter finger sensor and a 24-hour ambulatory heart rate monitoring system for the aged are presented. We also demonstrate the feasibility of extracting accurate heart rate variability measurements from photoelectric plethysmography signals gathered using a ring-type pulse oximeter sensor attached to the finger. We designed the heart rate sensor using a CPU with built-in ZigBee stack for simplicity and low power consumption. We also analyzed the various distorted signals caused by motion artifacts using a FFT, and designed an algorithm using a least squares estimator to calibrate the signals for better accuracy.