• Title/Summary/Keyword: Conventional form

Search Result 1,674, Processing Time 0.028 seconds

Hull Form Development for an AFRAMAX Tanker with a Composite Stern Frameline Concept

  • Kim, Ho-chung;Lee, Chun-ju;Kim, Su-hyung
    • Selected Papers of The Society of Naval Architects of Korea
    • /
    • v.1 no.1
    • /
    • pp.65-75
    • /
    • 1993
  • Hull form development for an AFRAMAX tanker characterized by the form parameters of $C_B\simeq0.8$, $L/B\simeq5.5$, $B/T\simeq3.5$, han been carried out by the application of ‘Composite Stern Frameline Concept’. The viscous resistance of the new form was much smaller than that of the conventional form. Form factor of the new form was only 0.18 compared to 0.30 for the conventional hull form, Nevertheless the propulsive efficiency was slightly lower and thus the required propulsion power was smaller by 5~6% at both full load and ballast condition. In addition, it is confirmed that introduction of the form factor method such as ITTC’78 method is highly advisable because there is a great risk of the underperdicting full scale resistance of the hull form whose form the extrapolation of moel resistance to full scale is to be based on Froude method with the correlation allowances usually applied to conventional hull forms.

  • PDF

Polymorphism of Clarithromycin

  • Sohn, Young-Taek;Rhee, Jae-Keol;Im, Weon-Bin
    • Archives of Pharmacal Research
    • /
    • v.23 no.4
    • /
    • pp.381-384
    • /
    • 2000
  • It is well recognized that physicochemical properties of drugs are affected by the type of polymorphic crystalline form of drugs. Clarithromycin is known to exist in at least three polymorphic crystalline forms. Since conventional means to obtain the most thermodynamically stable form (Form II) for the antibiotics is known to be associated with a low purity of the stable form, we developed a novel method to improve the purity of the crystalline form by a modification of the preparation process. The new method involved a simple recrystallization of clarithromycin in solvents having 5-12 carbon atoms (e.g., hexane and heptane) or ethers with 4-10 carbon atoms (e.g., isopropyl ether) and, thus, less likely to be associated with the problem in purity of resulting crystal. Differential scanning calorimetry and powder X-ray diffraction were used to compare the crystalline form of the resultant powder with Form IIcrystal prepared by the conventional method. The crystal prepared by the new method was identical to Form IIcrystal of the conventional method as evidenced by the lack of the exothermic peak near 11$0^{\circ}C$ in differential calorimetry scan, indicating that Form IIcrystal could be readily prepared by the new process. Therefore, these data indicated that the improvement in the purity of the Form IIcrystal for clarithromycin as well as a significant cost reduction is likely by the novel method.

  • PDF

A Study on the Forming Technologies for a Motor Piston and Improvement of Mechanical Properties (자동차용 피스톤의 성형기술과 기계적 성질의 개선에 관한 연구)

  • 김길준;박종옥;김영호
    • Proceedings of the Korean Society of Precision Engineering Conference
    • /
    • 2000.11a
    • /
    • pp.842-845
    • /
    • 2000
  • The purpose of this paper is to investigate the influences on mechanical properties of motor pistons manufactured by casting, conventional forging and powder forging, using the comparison of characteristics like microstructure, hardness, tensile strength, and elongation. To form conventional forging piston, the experiment of visioplasticity was performed. As the model material, plasticine was used. To form powder forging piston, the shape of piston was simplified as simple cup shape. Material properties like workability, density variation before and after forging, and strain loci of material during forging were investigated. Powder forging and conventional forging technologies were effective to gain dense microstructure. In powder forging, distribution of such dense microstructuer was uniform. For hardness, pistons from powder forging and conventional forging technologies were much better than that from casting. For tensile strength and elongation, powder forging and conventional forging technologies were also advantageous.

  • PDF

A Comparative Analysis Study on Distance Contrast Sensitivities According to Progressive Lens Design (누진렌즈 디자인에 따른 원거리 대비감도 비교분석 연구)

  • Shin, Dong-Min;Kim, Soo-Hyun;Jeong, Ju-Hyun
    • Journal of Korean Ophthalmic Optics Society
    • /
    • v.18 no.3
    • /
    • pp.241-246
    • /
    • 2013
  • Purpose: The aim of this study was a comparative analysis of the effect of distance contrast sensitivity when wearing free-form progressive lens and conventional progressive lens. Methods: The 20 subjects who do not have any ocular diseases were participated in this study. Contrast sensitivities at 5 different levels of spatial frequency were conducted by using FACT (Stereo Optical, USA). Results: Contrast sensitivity was measured for free-form progressive lens and conventional progressive lens in the order of right eye, left eye and binocular. Right/left/binocular contrast sensitivity values of the free-form progressive lenses compared to the conventional progressive lenses were higher 16%/17%/11% at A(1.5 cpd) of spatial frequency, 11%/5%/5% at B(3 cpd) of spatial frequency, 6%/6%/9% at C(6 cpd) of spatial frequency, 19%/16%/13% at D(12 cpd) of spatial frequency, 4%/3%/18% at E(18 cpd) of spatial frequency. Conclusions: In all the area of spatial frequency, distance contrast sensitivity values were measured highly on free-form progressive lens than on conventional progressive lens.

A Study on Application for Deck Plate Substitute Type Wood System Form of Frame Type Parking Lot (골조형 주차장의 Deck Plate 대체형 목제 시스템 거푸집 적용성 연구)

  • Shin, Yong-Jae;Shin, Woon-Sik;Heo, Jae-Won;Lim, Nam-Gi
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2006.11a
    • /
    • pp.123-126
    • /
    • 2006
  • Existing Deck Plate for a one of system forms, there is various advantage and application actual results increasing rapidly. But design of deck is depending on engineering data collections or design data on deck manufacture ordinarily. When construct, is responsible for deflection occurrence, And Because confirmation of crack occurrence region is impossible, there is difficulty of repair, reinforcement about crack and water leakage. According to got following conclusion as result that economic performance, preservation administration and repair reinforcement develops easy using steel truss snap tie by wedge pin on coating plywood that is slab Panel Wood System Form method of construction there is Deck Plate's advantage. (1) In stab lower part is exposed disjointing in which a criminal is fastened to be interrogated after construction acceptance and repair, reinforcement of crack is possible (2) Construction cost curtailment effect of about 29.2% than conventional type and about 10% than deck plate (3) Construction period reduction of about 3 day than conventional type and about 0.3 day than deck plate (4) Labor curtailment effect more than about $29{\sim}50%$ from conventional type

  • PDF

A Study on the Patterns of New Terrorism through the Comparative Analysis with Conventional Terrorism (고전적 테러리즘과의 비교 분석을 통한 뉴 테러리즘 양상에 대한 연구)

  • Song, Jae-Hyeong
    • Journal of National Security and Military Science
    • /
    • s.1
    • /
    • pp.113-154
    • /
    • 2003
  • We can feel the fear through the reports of outbreaking centers of terror. Also, we noticed through "the 9.11 terror" that there exists no safety zone from terrorism. However, we should question ourselves whether we are relaxing attention or ceasing anxiety too much in the perimeter, as in the peninsula of Korea. Through "the 9.11 terror", the vulnerability of the United State's homeland security has been exposed, giving a serious damage to the national pride. President Bush started the war against terror to strengthen global joints of anti-terrorism, identify terrorists and contribute to the global peace, adopting offensive realism including preemptive attack concept which means to remove the threat preemptively. In today's reality of international politics, where the inhuman, indiscriminate, and anti-civilizational international terror became greater, extending to the stage of war, the international societies' agony and focus lies on how to banish it. The 9.11 terrorism, which is a new form of terrorism, is being distinguished from conventional terrorism into new terrorism. New terrorism is a new form of terrorism meaning that you do not know the enemy, the goal does not exist and they conscientiously use the weapons of mass destruction. This paper is a work meant to help understanding new terrorism, the new form, by a comparative analysis with the conventional terrorism. Therefore the origin, concept and general characteristics new terrorism is picked out and the representative forms of it, which are suicide bombing, cyber, biochemical and nuclear terrorism, are analyzed in detail in theoretical manner.

  • PDF

Hull form design for resistance minimization of small-scale LNG bunkering vessels using numerical simulation

  • Pak, Kyung-Ryeong;Song, Gi-Su;Kim, Hee-Jung;Son, Hye-Jong;Park, Hyoung-Gil
    • International Journal of Naval Architecture and Ocean Engineering
    • /
    • v.12 no.1
    • /
    • pp.856-867
    • /
    • 2020
  • This paper aims to provide the most useful method of determining an optimum LCB position and design direction of fore- and aft-body hull shape for a SLBV. It is known that the SLBV has a lower length-to-beam ratio, larger Cb and simpler stern shape designed for the installation of azimuth thrusters comparing to those of conventional LNG carriers. Due to these specific particulars of SLBV, the optimum LCB position was very different to that of conventional LNG carrier. And various approaches were applied to determine the optimum fore- and aft-body hull shape. The design direction for the optimum hull-form was evaluated as the minimization of the total resistance which includes the wave-making resistance and form-drag with numerical simulation.

A Study on Conventional Expression of Hangul Ganchal (한글 간찰(簡札)의 상투적(常套的) 표현(表現) 고찰(考察))

  • Jeon, Byeong-yong
    • (The)Study of the Eastern Classic
    • /
    • no.37
    • /
    • pp.279-306
    • /
    • 2009
  • This study is purposed to observe conventional expression of Hangul Ganchal. The conventional expression of Hangeul Ganchal had set a pattern from 16th century to 17the century after establishing its regular form. It is mainly found in the introduction and the conclusion of the letters. Especially, they are concretely shown at an address form and greeting in the former, a farewell and the close in the latter. Generally, a native tongue was often used in address form at Suncheon Kim's Eongan in 16th century and Hyun-Poong Kwak's Eongan in 17th century. However, a Chinese character was commonly found in the introduction at Jingbo-Eongan-Dok in 19th century. Specifically, in case of response, the conventional expression of 'read your letter' was added in greeting part. In Suneon of 16th century, this type was gradually established to the form, and in Hyuneon of 17th century, a native tongue set a pattern. However, Jingeon of 19th century, a Chinese character was mainly used instead of a native tongue. The changing form of farewell and the close showed similar pattern as the aspect of greeting form. They seemed to be more simple and repetitive in Hyuneon compared with the form of Suneon. Furthermore, a Chinese character was dominated in the conclusion of letters in Jingeon. Consequently, the paper examined the two types of letter between Hangul letters and Chinese character letters were strongly associated with each other. It is expected that more details research will be coped with next study.

Design of Smartphone Secure Keypad Using Indirect Pattern (간접 패턴을 이용하는 스마트폰 보안 키패드 설계)

  • Choi, Dongmin
    • Journal of Korea Multimedia Society
    • /
    • v.25 no.7
    • /
    • pp.932-944
    • /
    • 2022
  • Smartphones, are currently equipped with high-performance hardware to process large amounts of data and provide most of the functions provided by desktop PCs. In addition, the smartphones enable quick user authentication through biometric information collected from embedded sensors. However, the biometric authentication method is sometimes rejected due to social and cultural environment, security vulnerabilities, and misrecognition rate. Thus, conventional authentication methods such as PIN and pattern authentication are still mainly used. Consider the latest foldable and bendable smartphones. These devices may be vulnerable to social engineering attacks as they use conventional authentication methods without considering their form factors. In this study, therefore, we propose an authentication method using partial elements of PIN and pattern authentication as a way to increase the security of the conventional authentication methods and consider the recent form factors. According to the performance evaluation results, our method provides improved safety compared to the conventional methods.

A Study of Components in Form-Based Codes of Small to Mid Cities in US - Focused on Zoning Codes Including Architectural Design Elements - (미국 중소도시의 형태기반코드 구성요소에 관한 연구 - 건축계획요소를 포함한 조닝코드 사례를 중심으로 -)

  • Park, Sung-Yong;Ahn, Dong-Joon
    • Journal of the Architectural Institute of Korea Planning & Design
    • /
    • v.34 no.4
    • /
    • pp.77-85
    • /
    • 2018
  • Rapid urbanization has fostered development of modern cities. Although Conventional zoning played its role to control urban development, it also segregated land uses and created homogeneous development pattern. Mega cities with satellite bed towns has not shown their unique identity and characters. In order to develop comprehensive approach which may bring social and physical enhancement can be difficult to achieve by considering city as a two dimensions. On contrary, extensive analysis and proposals require an approach which can perceive city with three dimensions. Form-Based Codes (FBCs) are appeared as an alternative to conventional zoning with different design process and principles. FBCs approach urban place with three dimension and giving priority to form rather than land use. The purpose of this study was to analyze the necessity of FBCs and its concept, components and how this would change urban characteristics in the aspects of architectural design through analysis on 4 case studies for zoning codes of US cities. Through comparison of components in Form-Based Codes of 4 different cases, this study can show the reasons for differences in application of Form-Based Codes and how detailed components would play a role to establish better urban environments.