• Structural Engineering and Mechanics
• /
• 제86권4호
• /
• pp.461-472
• /
• 2023

This paper proposes a novel method for increasing the distortional frame rigidity of off-rail box girder bridges for cranes by reinforcing the diaphragm with staggered truss. The study starts by using the Matrix Displacement Method to determine the shear angle of the staggered truss diaphragm under two assumptions: hinge joint and rigid joint. To obtain closed-form solutions for the transversal and longitudinal deformations and warping stress of the crane girder, the study employs the Initial Parameter Method and considers the compatibility of shear deformation at joints between the diaphragms and the girder. The theoretical solutions are validated through finite element analysis, which also confirms that the hinge-joint assumption accurately represents the shear angle of the staggered truss diaphragm in girder distortion. Additionally, the study conducts extensive parameter analyses to examine the impact of staggered truss dimensions on distortional stress and deformation. Furthermore, the study compares the distortional warping stresses of crane girders reinforced with staggered truss diaphragms and those reinforced with perforated ones, emphasizing the importance of incorporating stagger truss in diaphragms. Overall, this paper provides a thorough evaluation of the proposed approach's effectiveness in enhancing the distortional frame rigidity of off-rail box girder bridges for cranes. The findings offer valuable insights into the design and reinforcement of diaphragms using staggered truss to enhance the structural performance of crane girders.

• Steel and Composite Structures
• /
• 제45권1호
• /
• pp.67-82
• /
• 2022

In this paper, buckling and free vibration of imperfect, functionally graded beams, including porosities, are investigated, using a higher order shear strain theory. Due to defects during the manufacturing process, micro porosities may appear in the material, hence the appearance of this imperfection in the structure. The material properties of the beams are assumed to vary regularly, with power and sigmoid law, in the direction of thickness. A novel porosity distribution affecting the functionally graded volume fraction is presented. For the compact formulation used for cementite-based materials and already used in P-FGM, we have adapted it for the distribution of S-FGM. The equations of motion in the FG beam are derived using Hamilton's principle. The boundary conditions for beam FG are assumed to be simply supported. Navier's solution is used to obtain the closed form solutions of the FG beam. The numerical results of this work are compared with those of other published research to verify accuracy and reliability. The comparisons of different shear shape functions, the influence of porosity, thickness and inhomogeneity parameters on buckling and free vibration of the FG beam are all discussed. It is established that the present work is more precise than certain theories developed previously.

• 영어영문학
• /
• 제55권1호
• /
• pp.83-105
• /
• 2009

Modern poetry begins as criticism of modernity and, by so doing, rejects its idea of time. Modernity emphasizes sequential, linear, and irreversible time and progress. Williams rejects the modern view of time, and attempts to substitute literature for history assuming that literature can take us into the immediacy of time. His poetry asserts the true moment of experience as an immediacy, of words co-existent with things. He suggests that modernity and its idea of time already led to World War I and could clearly lead to an actual, manmade apocalypse with continued technological progress. Already in the 1920s, Williams sensed that he was living in a world where such an end could come all true, which is why Spring and All, his greatest early achievement, begins with a parody of the modern apocalypse. Throughout the work, Williams criticizes "crude symbolism" and expresses his longing to annihilate "strained associations," for he believes that the metaphoric or symbolic association is related to order, the center, and the traditional concept of time itself. The metonymic model of Spring and All substitutes a self-reflexive, open-ended, and indeterminate structure of time for the linear and closed one. Instead of supplying an end, Williams only asserts the rebirth of time and attempts to arrive at immediacy while attacking the mediacy of traditional art. His characteristic use of fragmentation and abrupt juxtapositions disrupts the reader's generic, conceptual, syntactic, and grammatical expectations. His radical poetic experiments, such as the isolation of words and the disruption of syntax, produce a sense of immediacy and force the reader to confront the presence of the poem. His destruction of traditional forms, of the tyrannous designs of history and time, opens up rather than closes the possibility of signification, and takes us into a moment of beginning while disallowing temporal distancing. Spring and All, as a criticism of the modern idea of time, asks us to view Williams's work not as an ahistorical text but as a cultural subversion of modernity.

• 영어영문학
• /
• 제55권1호
• /
• pp.153-176
• /
• 2009

This paper attempts an allegorical reading of female sexuality in Henry James' The Aspern Papers, wherein the narrator reveals his obsession with the love letters of the dead poet, Jeffrey Aspern. Not only the old papers, but does he also fetishize female protagonists in order to maintain his belief in the "great poet." Discussing such fetishistic elements in the novella is in order firstly to reveal the self-splitting logic of phallocentric language, and secondly to analyze the limitation of such language, which resonates with the Freudian construction of female sexuality as critically presented by Irigary. The first part of this study explains the binary structure of The Aspern Papers crystalized in the symbolic courtship in the Bordereaus' garden. It also represents the psychological mindset of the narrator/protagonist: symbolically located "outside," the narrator describes the two Bordereaus as being closed "inside" in a dark mansion, concealing the precious papers from him and the public. In other words, the women are nothing but the obstacle for the self-elected agent, the narrator, from the publication of the language and ideas of the "great man". The women are associated with secrecy and surreptitiousness, while the man with transparency and the truth. Second part of this paper mimics this In/Out binary as a means to reveal insufficiency, if not impropriety, of the predominant discourse of female sexuality constructed and controlled from the male perspective. Employing Irigary's argument, this paper reads the female characters as allegory for female sexual organs, which explains the narrator's inevitable failure. That is, female sexuality is something that cannot be articulated by the intruding language of a masculine subject. since the female sex as such is not only plural but also harmonious and self-contained,

• 한국환경복원기술학회지
• /
• 제17권2호
• /
• pp.61-71
• /
• 2014

A river fishway is a hydraulic structure enabling fish to overcome stream obstructions such as dams and weirs. The main aim of this paper is to investigate the collectibility of upstream-migrating fishes and hydraulic problems in pool-and-weir type fishway which has been established for upstream-migration at Namgang weir in the downstream of Namgang dam, and to grope for improvement measures which pool-and-weir type fishway can be switched to pool-and-partial weir type fishway through hydraulic field experiment. Exsisting fishway had problems which upstream-migrating fishes can not take a rest due to the seiche and vortex phenomena in pools and migrate to upstream because of height difference in entrance pool. In order to prevent hydraulically the seiche and vortex phenomena and establish rest area for fishes in each pool, we carried out hydraulic field experiments. In the fishway, it was to improve pool-and-weir into pool-and-partil weir, to decrease the height difference in entrance pool, and to reduce oriffice velocity of each pool. Also, we investigated fishes collectibility of after improving fishway for 6 days in September 2013. To resolve chronic problems(seiche-vortex phenomena and rest area for fishes), as weirs were remodeled into partial weir only which central part of weirs was part of non-overflow weir, we confirmed results that pool-and-weir type fishway could be switched to efficient pool-and-partial weir type fishway with relatively simple construction and low cost. Type-B which has the closed oriffices and the parts of non-overflow has the ideal conditions, but this conditions are limited to fishway of Namgang weir used in this study. Representative Ice-habor type fishway is pool-and-partial weir type fishway which has together parts of overflow and oriffices, and has excellent ability of upstream-migration. To switch from pool-and-weir type fishway to pool-and-partial weir type fishway, the size of oriffice has to be regulated by the discharge of fishway and the dimension on parts of non-overflow and overflow in weirs. Entrance pool is important facility which upstream-migrating fishes have to not only be collect but also charge with energy. In this study, entrance-pool is temporary and roughly-built, but fishes gather together more than the case of no entrance-pool. In the case of fishway which was protruded to downstream, as entrance of fishway turns toward or parallels to weir, the collectibility of fishway was excellent by attraction water.

• 전자공학회논문지
• /
• 제52권7호
• /
• pp.135-142
• /
• 2015

인체 구동 방식의 자가 발전기는 외부 환경에 덜 의존한다는 장점 덕분에 비상용 혹은 야외 활동 중의 소규모 전력 공급원으로 주목 받고 있다. 하지만 대부분의 자가 발전기는 전자기 유도 결합의 효율이 높지 않아 출력이 미미하며, 특정 부위의 근육만을 지속적으로 사용하는 단조로운 구동 방식을 택하고 있어, 사용 중에 쉽게 지루해질 뿐만 아니라 근피로가 쉽게 누적되어 실제 원하는 출력을 얻을 만큼 충분한 시간 동안 구동하는 것이 거의 불가능하다. 이러한 낮은 효율과 사용성의 문제로 인해 인체 구동 방식의 자가발전기가 실생활에서 사용되는 빈도는 높지 않다. 본 연구에서는 전자기 유도 효율이 높은 종축 결합 방식의 발전 장치를 간단한 구조로 구현하여 출력을 높이는 동시에, 자성체의 운동 관성에 의한 가속이 가능한 인체 구동 방식의 발전기를 설계 제작하였다. 개발된 발전기와 기존 상용 자가 발전기와의 비교 실험을 통해 높은 출력 뿐 아니라 장시간 구동이 가능함을 검증하였다. 아울러 인체 구동 발전기에서 실질적으로 중요한 요소임에도 불구하고 기존 연구에서 제시된 바 없는 인체의 투입 에너지를 실증적으로 파악하기 위해 호흡 가스 기반의 실제 운동 대사량 측정법에 근거한 실험을 시행하여 자가 발전기의 운동 부하를 추정하였다. 향후 성능 개선과 휴대성 증진을 통해 모바일 기기의 전력 지속 문제를 해결하는 데 기여할 수 있을 것으로 기대한다.

• 한국항해항만학회지
• /
• 제31권5호
• /
• pp.435-445
• /
• 2007

선체는 기본적으로 얇은 판부재들의 조합으로 구성되어 있으며 이들 중 상당수는 유공을 가진 유공판(Perforated plate)으로 이루어져있다. 선체에 설치된 유공판으로서는 선체 상갑판 해치(하역시설로 사용), 선저부의 거더와 플로어(중량경감과 선박 건조 및 검사시 통로확보용), 다이어프램(중량경감 및 파이프 관통의 목적)등이 있다. 이들 유공판에 압축하중이 작용하면 좌굴과 최종강도 특성이 크게 변화할 뿐만 아니라 수반되는 면내응력도 재 분포하게 되어 심각한 문제를 발생한다. 본 연구에서는 실선에서 사용 중인 유공보강판의 모델을 조사하여 비선형 유한요소법(ANSYS)을 사용하여 종방향 압축하중이 작용하는 경우에 대해서 유공비, 웹 치수, 웹 두께 그리고 보강재 단면을 변화시켜가며, 최종강도 시리즈 해석을 수행하고, 최종강도 예측 설계식을 제안하였으며, 식의 정도성을 검증하기 위하여 유한요소해석 결과와 비교하여 정도를 확인하였다. 제안된 설계식은 초기구조설계 시 유공보강판의 최종강도 계산에 유용하게 사용되리라 판단된다.

• 대한의용생체공학회:학술대회논문집
• /
• 대한의용생체공학회 1997년도 추계학술대회
• /
• pp.357-360
• /
• 1997

For medical students and doctors, knowledge of the 3-dimensional (3D) structure of the heart is very important in diagnosis and treatment of the heart diseases. 2-dimensional (2D) tools (e.g. anatomy book) or classical 3D tools (e.g. plastic model) are not sufficient or understanding the complex structures of the heart. Moreover, it is not always guaranteed to dissect the heart of cadaver when it is necessary. To overcome this problem, virtual dissection systems of the heart have been developed. But these systems are not satisfactory since they are made of radiographs; they are not true 3D images; they can not be used to dissect freely; or they can only be operated on the workstation. It is also necessary to make the dissection systems incorporating the various races and tribes because of the organ's difference according to race and tribe. This study was intended to make the 3D image of the heart from a Korean cadaver, and to establish a virtual dissection system of the heart with a personal computer. The procedures or manufacturing this system were as follows. 1. The heart from a Korean adult cadaver was embedded with gelatin solution, and serially cross-sectioned at 1mm-thickness on a meat slicer. Pictures or 153 cross-sectioned specimens were inputted into the computer using a digital camera ($756{\times}504$ resolution, true color). 2. The alignment system was established by means of the language of IDL, and applied to align 2D images of the heart. In each of 2D images, closed curves lining clean and dirty blood pathways were drawn manually on the CorelDRAW program. 3. Using the language of IDL, the 3D image and the virtual dissection system of the heart were constructed. The virtual dissection system of the heart allowed or ree rotation, any-directional sectioning, and selected visualization of the heart's structure. This system is expected to become more advanced, and to be used widely through Internet or CD-title as an educational tool for medical students and doctors.

• Journal of Hospice and Palliative Care
• /
• 제15권1호
• /
• pp.1-9
• /
• 2012

목적: 본 연구는 희망은 개인화된 유일하며 주관적이고 역동적인 경험이라는 가정 하에서 개인 경험에 근거한 희망 찾기 중재를 하는 데 도전해야할 문제점들을 토의하는 것을 목적으로 하였다. 방법: 연구자는 개인 경험에 근거한 희망을 향하여 가는 데 도전하여야 할 제한점과 요구되는 방안을 확인하기 위하여 비판적인 분석과 토의가 포함된 문헌 고찰을 사용하였다. 결과: 도전 과제들은 1. 개념화 문제로 대표되는 것들로서 종종 희망이 다양한 속성을 가진 표준화된 단일 구조나 현실적인 희망만이 강조되는 단일 구조로 또는 한 문헌에서 두 가지 오리엔테이션(상대주의 대 단일주의)의 혼합 속에서 기술되거나 사용되었다. 2. 완화돌봄을 받고 있는 환자들에 의하여 고유하게 경험되는 다양한 희망의 패턴이나 경험들에 대한 연구가 거의 없다. 3. 개인 경험에 근거한 희망 중재와 그 방법에 대하여 다룬 문헌이 거의 없다. 결론: 개념화 문제는 오랫동안에 걸쳐서 관련 학문 학자와 전문가에 내재되어온 고정된 오리엔테이션과 관계가 있는 것으로 보여진다. 따라서 이 문제는 우리들의 고정된 생각의 변화와 고정된 생각으로부터의 해방을 요구한다. 두 번째 도전 과제는 효과적이고 적절한 개인 경험에 근거한 희망 중재에 사용될 수 있도록 완화 간호 세팅에 있는 환자들의 다양한 희망 경험에 대한 다문화적 연구를 필요로 한다. 세 번째 도전 과제는 개인경험에 근거한 희망 중재를 위한 효과적인 방법을 찾을 것을 요구한다.

• 농촌지도와개발
• /
• 제16권2호
• /
• pp.363-384
• /
• 2009

This study aimed at finding directions for Korean agriculture to establish a new paradigm of sustainable development. Various problematic issues and concerns in the environment necessitate the transformation of Korea's development paradigm from unconditional growth to "Green Growth" through new policies on green value and review of various advanced researches. In this research, the environment-friendly agriculture's problems, particularly in agribusiness were analyzed. Drawing from Michael Porter's Value Chain Analysis, this research developed a value chain model in agriculture that reflects the environment and the present situations. Future directions in the agriculture sector were also discussed. Korea realized food self-sufficiency through the green revolution in the early 1970s. However, a lot of problems have also occurred, including ground and water pollution and the destruction of ecosystems as a result of the overuse of pesticides and chemical fertilizers. In the late 1970s, the growing interest on environment-friendly agriculture led to the introduction of sustainable methods and techniques. Unfortunately however, these were not innovative enough to foster environment-friendly agriculture. Thereafter, the consumers' distrust on agricultural products has worsened and concerns about health have increased. In view of this, the Ministry of Food, Agriculture, Forestry and Fisheries introduced in December 1993 a system of Quality-Certified Products for organic and pesticide-free agri-foods. Although a fundamental step toward the sustainability of the global environment, this system was not enough to promote environment-friendly agriculture. In 2008, Korea's vision is for "Low Carbon Green Growth" to move forward while also coping with climate change. But primary sectors in a typical value chain do not consider the green value of their operations nor look at production from an environmental perspective. In order to attain sustainable development, there is a need to use less resources and energy than what is presently used in Korean agricultural and value production. The typical value chain should be transformed into a "closed-loop" such that the beginning and the end of the chain are linked together. Such structure allows the flow of materials, products and even wastes among participants in the chain in a sustained cycle. This may result in a zero-waste sustainable production without destroying the ecosystem.