• 대한두경부종양학회지
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• 제23권1호
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• pp.67-70
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• 2007

Myxoma is an uncertain mesenchymal cell origin, characterized by irregular round, stellate or spindle cells surrounded by the matrix containing abundant mucoid material and scant vascularity. Their occurrence in descending order of frequency is in the heart, subcutaneous tissue, bone and genitourinary tract. In the head and neck region, the most predilection sites are mandible and maxilla(more than 80%). Laryngeal myxoma is extremely rare：only 5 cases have been reported in the English literature. We report a rare case of laryngeal myxoma. A 60-year-old man with hoarseness visited the out-patient department. The mass was located between the vocal fold and the vocal ligament, filling with the left laryngeal ventricle. We planned the laryngo-microsurgery and successfully excised using $CO_2$ laser. The histopathologic finding revealed the myxoma. After 18 months of surgery, there is no evidence of recurrence and mucosal scarring in the vocal fold. This report is the first case of laryngeal myxoma involving the laryngeal ventricle and the true vocal cord together.

• Smart Structures and Systems
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• 제10권4_5호
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• pp.353-373
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• 2012

The instrumented Canton Tower is a 610 m high-rise structure, which has been considered as a benchmark problem for structural health monitoring (SHM) research. In this paper, an improved automatic modal identification method is presented based on a natural excitation technique in conjunction with the eigensystem realization algorithm (NExT/ERA). In the proposed modal identification method, damping ratio, consistent mode indicator from observability matrices (CMI_O) and modal amplitude coherence (MAC) are used as criteria to distinguish the physically true modes from spurious modes. Enhanced frequency domain decomposition (EFDD), the data-driven stochastic subspace identification method (SSI-DATA) and the proposed method are respectively applied to extract the modal parameters of the Canton Tower under different environmental conditions. Results of modal parameter identification based on output-only measurements are presented and discussed. User-selected parameters used in those methods are suggested and discussed. Furthermore, the effect of environmental conditions on the dynamic characteristics of Canton tower is investigated.

• Structural Engineering and Mechanics
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• 제17권3_4호
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• pp.467-482
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• 2004

One of the uncertain damage parameters to jeopardize the safety of existing PSC bridges is the loss of the prestress force. A substantial prestress-loss can lead to severe problems in the serviceability and safety of the PSC bridges. In this paper, a nondestructive method to detect prestress-loss in beam-type PSC bridges using a few natural frequencies is presented. An analytical model is formulated to estimate changes in natural frequencies of the PSC bridges under various prestress forces. Also, an inverse-solution algorithm is proposed to detect the prestress-loss by measuring the changes in natural frequencies. The feasibility of the proposed approach is evaluated using PSC beams for which a few natural frequencies were experimentally measured for a set of prestress-loss cases. Numerical models of two-span continuous PSC beams are also examined to verify that the proposed algorithm works on more complicated cases.

• 한국가축번식학회지
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• 제10권1호
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• pp.9-18
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• 1986

Breeding and infertility status of Holstein cows reared in pasture of High-land was investigated. The results obtained were summarized as follows; 1. Eight hundred and forty Holstein cows with heifers (12.4%), 3 years old cows (19.3), 4 years old cows (16.7%), 5 years old cows (12.5%), 6 years old cows (11.4%), 7 years old cows (13.2%), 8 years old cows (9.4%) and above 9 years old cows (5.1%) were investigated. 2. They were 72.4% of conceived cows, 8.2% of uncertain pregnancy, 7.7% of physiological empty and 11.7% of reproductive disorder. 3. The percentage of cow concepted with 1, 2, 3 and more than 4 times of A.I. was 49.2, 28.8, 14.6 and 7.4% respectively. 4. In the nutritional condition of infertile cows, excellent, good, fair and poor was 7.1, 30.6, 36.7 and 25.5%, respectively. 5. Among 98 infertile cows, distribution of reproductive disorder was 41.8, 37.8, 5.1, 5.1 and 11.2% in ovary, uterus, vagina, oviduct and others, respectively. Ovary showed higher percentage than any other reproductive organs. Among the ovarian syndromes, lutein cystic ovary, follicular cystic ovary, and persistent corpus luteum were 31.7, 26.8 and 19.5%, respectively. 6. Four years old cow showed highest distribution (16.4%) among the aged groups in disordered cows. In the syndromes of reproductive disorder, latent endometritis showed higher frequency (14.3%) than any others. 7. Infertile cows with complex syncrome of genital disease was 29.6%.

• 천문학회보
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• 제39권1호
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• pp.37.2-37.2
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• 2014

Gas in disk galaxies interacts nonlinearly with a underlying stellar spiral potential to form galactic spiral shocks. Numerical simulations typically show that these shocks are unstable to the wiggle instability, forming non-axisymmetric structures with high vorticity. While previous studies suggested that the wiggle instability may arise from the Kelvin-Helmholtz instability or orbit crowding of gas elements near the shock, its physical nature remains uncertain. It was even argued that the wiggle instability is of numerical origin, caused by the inability of a numerical code to resolve a shock that is inclined to numerical grids. In this work, we perform a normal-mode linear stability analysis of galactic spiral shocks as a boundary-value problem. We find that the wiggle instability originates physically from the potential vorticity generation at a distorted shock front. As the gas follows galaxy rotation, it periodically passes through multiple shocks, successively increasing its potential vorticity. This sets up a normal-mode that grows exponentially, with a growth rate comparable to the orbital angular frequency. We show that the results of our linear stability analysis are in good agreement with the those of local hydrodynamic simulations of the wiggle instability.

• Wind and Structures
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• 제21권5호
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• pp.461-487
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• 2015

In recent years, the Graphics Processing Unit (GPU) has become a competitive computing technology in comparison with the standard Central Processing Unit (CPU) technology due to reduced unit cost, energy and computing time. This paper describes the derivation and implementation of GPU-based algorithms for the analysis of wind loading uncertainty on high-rise systems, in line with the research field of probability-based wind engineering. The study begins by presenting an application of the GPU technology to basic linear algebra problems to demonstrate advantages and limitations. Subsequently, Monte-Carlo integration and synthetic generation of wind turbulence are examined. Finally, the GPU architecture is used for the dynamic analysis of three high-rise structural systems under uncertain wind loads. In the first example the fragility analysis of a single degree-of-freedom structure is illustrated. Since fragility analysis employs sampling-based Monte Carlo simulation, it is feasible to distribute the evaluation of different random parameters among different GPU threads and to compute the results in parallel. In the second case the fragility analysis is carried out on a continuum structure, i.e., a tall building, in which double integration is required to evaluate the generalized turbulent wind load and the dynamic response in the frequency domain. The third example examines the computation of the generalized coupled wind load and response on a tall building in both along-wind and cross-wind directions. It is concluded that the GPU can perform computational tasks on average 10 times faster than the CPU.

• 지역사회간호학회지
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• 제6권2호
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• pp.212-233
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• 1995

Cerebrovascular diseases in Korea is an important health problem since mortality and mobidity have been increasing rapidly. Cerebrovascular diseases marked the 2nd rank of cause specific death rate in 1993. The ploblem of emotion after a stroke has received very little attention from the nursing profession until recently. Even the frequency of the emotional disorder after stroke is uncertain, and there has been very little research. Emotional disorder after stroke was related to limited social function, guilty conscience, helplessness, hopelessness, powerlessness, alienation, and damage of self-image. In the stroke patient, hope may be related to a rehabilitation or enhancing physical condition. Inspiring hope is necessary when stroke patients are unable to mobilize energy on their own behalf and perceive limited or no person choices available. Inspiring hope is an intervention that can be used with many nursing diagnoses, especially when feelings of helplessness, hopelessness, powerlessness, and depression are present. The nurse can inspire hope by understanding the hoping process. On the basis of this literature review, the following suggestions are prosed. 1) Qualitative studies on hope have been done to indentify variables that affect maintenance of hope in the chronically ill patients. 2) In the development of an instrument to measure hope, the validity, reliability, and cultural property of the hope have been estabilished.

• The Journal of Asian Finance, Economics and Business
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• 제6권1호
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• pp.281-288
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• 2019

This study examines the relationship between R&D intensity and disclosure. R&D activities are essential in bringing innovation to companies. However, R&D activities are naturally uncertain and increase information asymmetry. Thus, firms with high R&D activities are more likely to have the incentive to communicate the potential of R&D investment to the market through voluntary disclosure and, concurrently, resolve information asymmetry. Meanwhile, incentives to less voluntary disclosure exist because of the proprietary cost and the risk of competitiveness loss. Furthermore, the uncertainties inherent in R&D activities caused the possible decrease in the information accuracy. For the two opposing views, this study investigates the relationship between R&D intensity and disclosure frequency using the Regulation Fair Disclosure data in Korea. Moreover, the relationship between R&D intensity and usefulness of the information disclosed is also examined. Using firm sample listed in the 2011-2016 Korea Stock Market, results show that firms with high R&D intensity make disclosures more frequent. Subsequently, the analysis using forecast sample shows that management forecast error is higher in firms with high R&D intensity. This research contributes to the existing literature by presenting evidence that R&D intensity is a significant factor affecting manager's disclosure behavior and information usefulness.

• Clinical and Experimental Reproductive Medicine
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• 제7권1_2호
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• pp.27-34
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• 1980

The status of artificial insemination was surveyed by investigating 20796 heads of adult dairy cattle out of 30464 heads at 1649 dairy farms located Seoul and Gyung-Gi and Chung-Cheong province area, and the results are as follows: 1. There were 286 small farms feeding less than 5 heads occupying 17.3% of total farm number, and 1083 medium sized dairy farms feeding between $6{\sim}20$ heads occupying 65.64% and also 280 large dairy farms feeding more than 21 heads occupying 17.06% of total. 2. Population of cow aging from 2 to 6 years were 87.26% and among 20907 heads of dairy cattles which had calved previously 13196 heads had histories of one to four calving 90.40%. 3. The successful conception rate with first A. I. occupied only 53.43% and 92.4% after third A. I. service. The average A. I. frequency for successful conception per/head was 1.8 times. 4. The breeding status was pregnancy 61.72%, uncertain pregnancy 19.39%, and as physiological vacancy 12.48% and reproductive disorders 10.62%. 5. Among 1264 heads of reproductive disorders 856 heads were clue to ovarian diseases and occupied 68.98% of total disorders and uterus diseases 10.64% and repeat breeders occupied 17.64%.

• Earthquakes and Structures
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• 제5권1호
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• pp.111-127
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• 2013

This paper describes effects of infill walls on behavior of RC frame with low strength, including numerical modeling, modal testing and finite-element model updating. For this purpose full scaled, one bay and one story RC frame is produced and tested for plane and brick in-filled conditions. Ambient-vibration testis applied to identify dynamic characteristics under natural excitations. Enhanced Frequency Domain Decomposition and Stochastic Subspace Identification methods are used to obtain experimental dynamic characteristics. A numerical modal analysis is performed on the developed two-dimensional finite element model of the frames using SAP2000 software to provide numerical frequencies and mode shapes. Dynamic characteristics obtained by numerical and experimental are compared with each other and finite element model of the frames are updated by changing some uncertain modeling parameters such as material properties and boundary conditions to reduce the differences between the results. At the end of the study, maximum differences in the natural frequencies are reduced on average from 34% to 9% and a good agreement is found between numerical and experimental dynamic characteristics after finite-element model updating. In addition, it is seen material properties are more effective parameters in the finite element model updating of plane frame. However, for brick in-filled frame changes in boundary conditions determine the model updating process.