• Advances in materials Research
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• 제6권1호
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• pp.65-78
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• 2017

A hat section was designed and developed for maximum impact energy absorption and/or transmission under low velocity impact. Towards this, different hat sections, having material properties of thermoplastic, were modeled and investigated numerically using finite element analysis (FEA) in the range of 20-50 J impact energy. In the study it was experienced that the design configuration of hat section with curvilinear profile (HSCP) was excellent in energy attenuation capacity and for even distribution of maximum impact force around and along the hat section under low velocity impact loading. To validate the numerical findings, polypropylene copolymer (Co-PP) HSCP and low density polyethylene (LDPE) HSCP were developed and evaluated experimentally in the said impact energy range. A correlation was established between FEA and experimental test results, thereby, validating a numerical model to predict results for other thermoplastic materials under given range of impact energy. The LDPE HSCP exhibited better performance as compared to Co-PP HSCP in the said range of impact energy. The findings of this study will enable the engineers and technologists to design and develop low velocity impact resistance devices for various applications including devices to protect bone joints.

• 복식
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• 제51권4호
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• pp.57-69
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• 2001

The purpose of this study is to examine the costume represented In human clay figures of ancient Shilla dynasty. The results of this study could be summarized as follows: 1. Horse-riding clay figures of Gumryoung tomb. At first, human-A wears a brimed-triangular hat, a Jacket, a checked pants. The brimed-triangular hat is decorated with bird-feather shape. Besides, a jacket is tied with a waist belt, and the waist belt is connected with a shoulder belt and a squared block of back. Also round bells are decorated 15 in the hat, 4 In connection points of the waist belt and the shoulder belt, and 13 in the squared block of back. Human-B wears a hairband type hempen hood, a Jacket, a pants with vertical stripes. and something is rounded from right shoulder to left side. It is one of the symbols as a shaman. 2. Other clay figures. The hats examined from other clay figures are \circled1 Triangular hat, \circled2Hat decorated with bird-feather shape, \circled3 Brined hat and \circled4 Hairband type hempen hood. Next, six kinds of hair styles examined are \circled1 a topknot, \circled2 a slanted topknots, \circled3 two topknots on both sides, \circled4(round) chignon, \circled5 hair tied at the top and plastered down, and tile last, \circled6 ponytailed style on both sides. The costume examined is a jacket and a pants.

• Journal of Mechanical Science and Technology
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• 제17권4호
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• pp.501-510
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• 2003

The spot welded sections of automobiles such as the hat and double hat section members, absorb the most of the energy during the front-end collision. The purpose of this study was to analyze the collapse characteristics of spot welded section members with respect ttl the pitch or spot welds on flanges. through impact experiments and computation for para-closed sections and perfectly closed sections. The hat shaped section members were tested at the impact collapse velocities of 4.72 m/sec, 6.54 m/sec and 7.19 m/sec and double hat shaped section members were tested at the impact collapse velocities of 6.54 m/sec, 7.19 m/sec and 7.27 m/sec. A commercial LS-DYNA3D was used to simulate the collapse behavior of the hat and double hat shaped section members. The validity of the simulation was to be proved by comparing the simulation results and the experimental results.

• Food Science and Biotechnology
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• 제16권3호
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• pp.457-462
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• 2007

Histone acetyltransferase (HAT) is a family of enzymes that regulate histone acetylation. Dysfunction of HAT plays a critical role in the development of cancer. Here we have screened the various plant extracts to find out the potent HAT inhibitors. The bellflower (Platycodon grandiflorum) root have exhibited approximately 30% of the inhibitory effects on HAT activity, especially p300 and CBP (CREB-binding protein) at the concentration of $100\;{\mu}g/mL$. The cell viability was decreased approximately 52% in LNCaP cell for 48 hr incubation. Furthermore, mRNA level of 3 androgen receptor target genes, PSA, NKX3.1, and TSC22 were decreased with bellflower root extract treatment ($100\;{\mu}g/mL$) in the presence of androgen. In ChIP assay, the acetylation of histone H3 and H4 in PSA promoter region was dramatically repressed by bellflower root treatment, but not TR target gene, Dl. Therefore, the potent HAT inhibitory effect of bellflower root led to the decreased transcription of AR target genes and prostate cancer cell growth with the repression of histone hyperacetylation.

• 한국해양환경ㆍ에너지학회지
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• 제13권2호
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• pp.105-111
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• 2010

조류발전용 HAT 임펠러 설계에 대한 성능 비교 연구를 통하여 설계 개선방향에 대하여 고찰해 보았다. 기존의 조류발전용 임펠러는 풍력에서 사용하고 있는 설계 개념을 그대로 사용하는 경향이 있으며 밀도 차이가 크고 풍력과는 다른 조류발전의 특성을 고려하여 새로이 설계된 임펠러와 기존의 임펠러를 비교하였다. 향후 계산에 의한 비교 뿐 아니라 실험 그리고 경사류등과 같은 특수한 경우에 대한 검증을 수행할 계획이다.

• Composites Research
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• 제25권6호
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• pp.224-229
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• 2012

정찰 및 감시를 위한 어레이 안테나가 내장된 날개는 컷아웃이 수반되기 때문에 구조성능이 저하된다. 본 논문에서는 단순화된 복합재 날개에 어레이 안테나 탑재시 안테나성능 저하와 날개구조 성능 저하를 최소화할 수 있는 복합재 모자형 보강재의 두께에 대해 최적설계를 수행하였다. 최적의 모자형 보강재 형상 선정을 위하여 모자형 보강재의 웹 경사도와 플랜지의 길이에 변화를 주어 상용 유한요소해석 프로그램을 이용하여 구조 해석을 수행하였다. 복합재 모자형 보강재형상에 대하여 응력과 좌굴에 대한 구속조건으로 상용 최적화 프로그램인 VisualDOC와 상용 유한요소해석 프로그램을 이용하여 최적화를 수행하여 보강재의 두께를 결정하였다.

• 대한기계학회논문집A
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• 제25권7호
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• pp.1131-1138
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• 2001

This paper concerns the crashworthiness of the widely used vehicle structure, the spot welded hat and double hat shaped section members, which are excellent on the point of the energy absorbing capacity and low production cost. The target of this paper is to analyze the energy absorption capacity of the structure against the front-end collision, and to obtain useful information for designing stage. Changing the spot weld pitches on the flanges, the hat and double hat shaped section members were tested on the axial collapse loads in impact velocities of 4.72m/sec, 6.54m/sec, 7.19m/sec and 7.27m/sec. To efficiently review the collapse characteristics of these sections, the simulation have been carried out using explicit FEM package, LS-DYNA3D. The solutions are compared with results from the impact collapse experiments.

• 한국수산과학회지
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• 제52권6호
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• pp.719-724
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• 2019

This study is an extension of our previous model for a size-based fish stock assessment. In the previous model, we applied an allometric length-weight relationship (W=α·L^β) to convert lengths of fish to weights, and estimated those parameters α and β, using data about lengths and weights aggregated over years. In this study, we focused on whether consideration of temporal (e.g., year-to-year) variability in those estimates (i.e., ${\hat{\alpha}}$ and ${\hat{\beta}}$) would contributive. After calculating year-specific estimates (i.e., year-specific pairs of ${\hat{\alpha}}$ and ${\hat{\beta}}$) by applying data about lengths and weights separated by year, we evaluated the contribution of those year-specific pairs of ${\hat{\alpha}}$ and ${\hat{\beta}}$ to the performance of the size-based stock assessment model. The model with such year-to-year variability being considered (lower AIC) outperformed that with the variability being ignored (higher AIC). We illustrated this study using data on Korean chub mackerel Scomber japonicus from 2005-2017.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
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• pp.108-111
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• 2009

We have determined the electronic energy level alignment at the interface between 4,4'-bis-N-phenyl-1-naphthylamino biphenyl (NPB) and 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HAT-CN) using ultraviolet photoelectron spectroscopy (UPS). The highest occupied molecular orbital (HOMO) of 20 nm thick HAT-CN film was located at 3.8 eV below the Fermi level. Thus the lowest unoccupied molecular orbital (LUMO) is very close to the Fermi level. The HOMO position of NPB was only about 0.3 eV below Fermi level at NPB/HAT-CN interface. This enables an easy excitation of electrons from the NPB HOMO to the HAT-CN LUMO, creating electron-hole pairs across this organic-organic interface. We also study the interaction of HAT-CN with a few metallic surfaces including Ca, Cu, and ITO using UPS and ab-inito electronic structure calculation techniques.

• 복식
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• 제59권8호
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• pp.66-81
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• 2009

The purposes of this study were to analyze the formative relationship between Surrealistic clothes and hat with the focus on the period from the 1990's to 2008 and to find out the development direction of next hat design. The method to analyze the relationship between clothes and hats was the formative analysis by Marian L. Davis and Marilyn R. Delong. Hat design of surrealism was cylindrical or tear drop in a shape according to the principle of $D{\acute{e}}paysement$ and Trompe l'oeil, and was similar with the Form of a jacket, a sleeve, or a skirt. In color, accent color coordination mainly appeared and sometimes contrast color coordination induced illusion effect. In material, a variety of materials were used according to the principle of $D{\acute{e}}paysement$ and Trompe l'oeil, and contrast was widely used like color. In Decoration, the decoration or pattern of clothes was intactly applied to hats. The results suggest that clothes and hat have an organic relationship, and a hat style is changed with formative elements of clothes.