• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.6
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• pp.498-504
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• 2011

The flapping characteristics and advance ratios at torque equilibrium state of autorotation were investigated when the airspeed, shaft angle, and pitch angle were varied. To simulate the airspeed increase, the aerodynamic data analyzed by using the compressible Navier-Stokes solver and Pitt/Peters inflow theory were used. Transient Simulation Method(TSM) was used to catch the torque equilibrium states. The maximum flapping angles at torque equilibrium state were correlated to the airspeed, shaft angle, and pitch angle. By comparing flapping behavior to the variation of advance ratio, the phenomenon that the extension of reverse flow area of retreating blade affects the characteristics of autorotation was qualitatively considered.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2054-2062
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• 2012

The performance of organizational culture effectiveness has been supported by several researchers. Since Peters & Waterman acclaimed that the excellent companies have their unique culture type, the effectiveness of organization culture have been practically supported. Organization culture is closely related to employees' satisfaction and commitment and contributed to the subjective performance and financial performance in terms of individual and organizational level. Organizational culture is a valuable resources and competitive advantage for the successful growth. Thefore, I have proposed some proposition regarding the type and strength of organization culture and the interaction effect of internal consistency which should be studied for more fundamental study of the effectiveness of organizational culture.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.170-173
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• 2021

Background: The Slender racer (Orientocoluber spinalis Peters, 1866) has recently been reclassified to the new genus Orientocoluber from Hierophis. Ecological knowledge of this species is limited due to its highly mobile behavior. On 17 July 2020, we captured a female O. spinalis on Oeyeon Island, Boryeong-si, Republic of Korea, and collected its feces for a diet analysis. We observed snake scales from the collected feces and subsequently determined the prey species through morphological and molecular methods. Results: We initially hypothesized that the extracted fecal sample scales belonged to H. vibakari, due to their thin keel and rhombus shape. We also amplified H. vibakari DNA from the extracted fecal sample using Illumina sequencing methods. Our morphological and molecular results suggest that O. spinalis predates H. vibakari on Oeyeon Island. Conclusion: This is the first report of O. spinalis predating another snake species, ophiophagy, and implies that H. vibakari may be a crucial prey item for O. spinalis on Oeyeon Island.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.97-105
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• 2023

Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH₄⁺ and NO₃^-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH₄⁺:NO₃^- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH₄⁺ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH₄⁺ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO₃^- :NH₄⁺ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO₃^- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO₃^- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

• Journal of Korean Neurosurgical Society
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• v.59 no.3
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• pp.247-249
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• 2016

Craniosynostosis has a varied clinical spectrum, ranging from isolated single suture involvement to multi-sutural fusions. Greater understanding of the pathogenesis of craniosynostosis has led to the development of practical treatment protocols. Three stages of growth have determined the approach to managing craniosynostosis : the early period, up to 12 months; the intermediate period, from 1 to 10 years; and the late period, beginning at 10 years. This review discusses current surgical management and future perspectives in craniosynostosis.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.4
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• pp.297-305
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• 2011

In this study, the aeroelastic analysis of rotorcraft in forward flight has been performed using dynamic inflow model to handle unsteady aerodynamics. The quasi-steady airload model based on the blade element method has been coupled with dynamic inflow model developed by Peters and He. The nonlinear steady response to periodic motion is obtained by integrating the full finite element equation in time through a coupled trim procedure with a vehicle trim for stability analysis. The aerodynamic and structural characteristics of dynamic inflow model are validated against other numerical analysis results by comparing induced inflow and blade tip deflections(flap, lag). In order to validate aeroelastic stability of dynamic inflow model, lag damping are also compared with those of linear inflow model.

• Land and Housing Review
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• v.1 no.1
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• pp.125-134
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• 2010

Integrating corporate culture in a merger enterprise is considered as one of the most important variables to decide M&A success. This study established a conceptional model according to the preceding study on integrating corporate culture and organizational effectiveness, and formulated a hypothesis on the interrelation between a seven factors of corporate culture proposed by Pascale & Athos and Peters & Waterman and organizational effectiveness. The result of applying multi-regression analysis to test the hypothesis is as follows; firstly, all of a merger enterprise's cultural factors have meaningful influence on job involvement among organizational effectiveness; secondly, all of them have sincere influence on job satisfaction among organizational effectiveness except shared value; and thirdly, all of them except skill have significant influence on organizational harmony among organizational effectiveness. This is a significant empirical and exploratory study to ascertain the variables of corporate culture factors, and to verify their effects on organizational effectiveness.

• Korea-Australia Rheology Journal
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• v.15 no.4
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• pp.197-208
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• 2003

Two measures of distributive mixing are examined: the standard deviation $\sigma$ and the maximum error E, among average concentrations of finite-sized samples. Curves of E versus sample size L are easily interpreted in terms of the size and intensity of the worst flaw in the mixture. E(L) is sensitive to the size of this flaw, regardless of the overall size of the mixture. The measures are used to study distributive mixing for time-periodic flows in a rectangular cavity, using the mapping method. Globally chaotic flows display a well-defined asymptotic behavior: E and $\sigma$ decrease exponentially with time, and the curves of E(L) and $\sigma$ (L) achieve a self-similar shape. This behavior is independent of the initial configuration of the fluids. Flows with large islands do not show self-similarity, and the final mixing result is strongly dependent on the initial fluid configuration.

• Journal of Environmental Impact Assessment
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• v.2 no.2
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• pp.49-53
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• 1993

Before the EIA was established in the Federal Republic of Germany, the impact mitigation principle - a planning instrument, which has its legal foundation in the German nature conservation legislation already had {and still has} the function to valuate environmental impacts. The valuation principles and methods which have been developed in correlation to this instrument are now also used in the EIA. Particularly for the valuation of alternating effects on the different ecological landscape functions and for the valuation of ecological mitigation and compensation measures this valuation methods are used. These methods base on a special kind of modelling nature and environment Following the aim of the nature conservation act, which is to save the capacity of the landscape to perform its essential functions, not the ecological factors (soil, water, air etc.) itselfs are evaluated but the ecological functions of the landscape, which are based on the ecological factors.

• Water for future
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• v.44 no.6
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• pp.37-41
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• 2011

미국 캘리포니아 주 어바인 시에 위치한 피터스 캐년 샛강(Peters Canyon Creek) 수중에 과포함되어 있는 셀레늄(Dissolved Selenium)과 질산성 질소(Nitrate-N)를 제거하려는 목적으로 바이오 필터 셀 시스템을 시범 시공하였다. 바이오 필터셀 시스템은 3m(높이) ${\times}$ 65m(길이) ${\times}$ 14m(폭) 크기를 가진 상자형태의 셀을 기준으로 취수 및 전처리 시스템과 후처리 시스템으로 구성되었으며, 셀은 여러 종류의 지오신세틱스와 거친 표면을 가지고 있는 자갈을 이용하여 건설되었다. 특히, 지오신세틱스가 가지고 있는 장점인 유연성(flexibility)과 화학적 안정성으로 인한 무반응성(non reactive material)등은 성공적인 시스템 구축에 큰 영향을 주었다.