• Korean Journal of Heritage: History & Science
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• v.6
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• pp.158-162
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• 1972

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.5
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• pp.61-74
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• 2021

This study investigated the relationship between the social legitimacy and financial performance perceived for venture company. In particular, social legitimacy was classified into prior experiences, organizational competency, market-related, and government-related legitimacy according to the characteristics of venture businesses, and its effect on the financial and non-financial performance of venture businesses was verified. Data were collected by conducting a survey among 300 domestic venture businesses. According to the results it can be understood that social legitimacy affects the financial and non-financial performance of venture businesses. In other words, it was found that the acquisition of resources from external investors and governments which is justified by stakeholder and investors, venture business executives and employees' prior experience such as start-up experience, and retention of outstanding talent, etc., developing trust from the market and consumers through high organizational competency and differentiated product provision, have a positive effect on the financial and non-financial performance of venture companies. It can be interpreted that higher survival is possible through running the venture businesses with social legitimacy. In addition, this study is meaningful in that it presents a new standard for survival through measuring the relationship of the influence on substantial performance of venture businesses by expanding the existing sociological research to business management research.

• Journal of The Geomorphological Association of Korea
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• v.24 no.4
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• pp.27-41
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• 2017

In this study, geomorphological and geological research has been carried out to estimate the possibility of ancient port location near Hwaseong Dangseong. Geomorphological characteristics around Eunsupo were analyzed through comparison of past and present topographic maps and field survey. Grain size, age dating, and geochemical analysis on surface sediments and borehole sediments were performed. Through the geomorphological characteristics analysis, it was interpreted that Eunsupo area was submerged in seawater especially at high tide in the past, and that ships could approach to the inside of the area through the tidal channel which were developed in the area. It is also assumed that ships were anchored at a low elevation point in the area. The paleo-environmental change in the area was analyzed based on the classification of sedimentary environment using grain size distribution of surface and borehole sediments and geochemical analysis. It was confirmed that the geomorphological interpretation for the possibility of ancient port location coincided well with the paleo-environmental change interpreted through sediment analysis. This study is a basic study for estimating ancient port location, and it is expected that more accurate paleo-environmental changes will be restored through detailed geomorphological survey and additional borehole analysis in the future research.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1627-1631
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• 1992

It often occurs in J-R testing that some initial crack extension (.DELTA.a) data points have anomalous negative values. The reason for the apparent negative crack growth is due to the analysis method. The phenomenon as a possible source of error in determining $J_{IC}$ or J-R curve from partial unloading compliance experiments may be eliminated by the compliance correction equation or the offset technique. In this study, the correction methods are suggested and examined by the measurement of the actual crack length and $J_{JC}$ analysis.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.29B no.7
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• pp.52-61
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• 1992

An iterative scheme for computing the three-dimensional position and the surface orientation of an opaque object from a singel shaded image is proposed. This method demonstrates that calculating the depth(distance) between the camera and the object from one shaded video image is possible. Most previous research works on $'Shape from Shading$' problem, even in the $'Photometric Stereo Method$', invoved the determination of surface orientation only. To measure the depth of an object, depth of the object, and the reflectance properties of the surface. Assuming that the object surface is uniform Lambertian the measured intensity level at a given image pixel*x,y0becomes a function of surface orientation and depth component of the object. Derived Image Irradiance Equation can`t be solved without further informations since three unknown variables(p,q and D) are in one nonlinear equation. As an additional constraints we assume that surface satisfy smoothness conditions. Then equation can be solved relaxatively using standard methods of TEX>$'Calculus of VariationTEX>$'. After checking the sensitivity of the algorithm to the errors ininput parameters, the theoretical results is tested by experiments. Three objects (plane, cylinder, and sphere)are used. Thees initial results are very encouraging since they match the theoretical calculations within 20$\%$ error in simple experiments.> error in simple experiments.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.3
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• pp.520-527
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• 1988

Liquid ejectors are widely used as marine pumps, inducer stage for the boiler feed water pump, boiler recirculating pump, cooling water recirculating pump in boiling water type nuclear reactor and a deep well pump, because of their high working confidence and simplicity. Furthermore, it requires only a modest net positive suction head for cavitation-free operation and it can be installed in remote location from mechanical power source. It is not easy to presume the friction losses, because it is complicately affected by area ratio, flowrate ratio, nozzle spacing, throat length, shape of liquid ejector and so on. Therefore, the optimization of liquid ejector design is still dependent, to a large extent, on the experimental results and empirical procedures. On the design of the liquid ejector, the area ratio and the nondimensional throat length are the most important design factors among the mentioned above. In this experiment, the effects of the area ratio and the nondimensional throat length to ejector efficiency are carried out systematically by the combination of 4 kinds of motive nozzle and 2 kinds of throat length. In this paper, the present experimental results are compared with the calculated ones by the previous computer aided design program based on one dimensional flow equation. And also, an empirical equation for the working limit of liquid ejector is reported.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.1
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• pp.51-61
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• 1993

A systematic approach of the energy method is proposed for analysis of axisymmetric deep drawing in which the total deforming region is divided into five sections by the geometric characteristic. The corresponding solution is found through optimization of the total energy dissipation with respect to some parameters assumed in the kinematically admissible velocity field defined over each region. The sheet blank is divided into three-or five-layers to consider the bending effect. For the evaluation of frictional energy, it is assumed that the blank holding force acts on the outer rim of the flange and that the contact pressure acting on punch shoulder or die shoulder has uniform distributions, respectively. The computed results by the present method are compared with the experiment and the computed results by the elastic-plastic finite element method for the distribution of thickness strain and the relation between the punch stroke and punch load. The results for the case of multi-layers show better agreements than for the case of a single layer in load vs. stroke relation and strain distribution. It is thus shown that the multi-layer technique can be effectively employed in analyzing axisymmetric deep drawing in connection with the energy method.

• Journal of The Geomorphological Association of Korea
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• v.26 no.2
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• pp.39-54
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• 2019

In this paper, based on evidence of coastal sediment, we show that erosion and sedimentation environments are very sensitive to sea level changes during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). We identified four sedimentary units(4.57-3.07m), which formed in the Dark Age Cool Period (DACP), MWP and LIA were classified based on the lithostratigraphy, grain size distribution, magnetic susceptibility and geochemistry of a drilling core taken from the west coast of Hwaseong City. The unconformity surfaces as boundaries of the units were also identified by the lithostratigraphy shown on the drilling core. We propoese that sedimentation was dominant in the area during the periods of sea level rise, whereas erosion prevailed during the periods of sea level fall. Particularly, extreme events, such as floods and typhoons are believed to have accelerated these processes, and we found the associated evidence in sediments of two units. This study provides an example of estimating the relative sea level variation using coastal sediments and may be useful for studying past sea level changes around the Korean Peninsula.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1632-1642
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• 1992

When a blind hole of small diameter is drilled in the field of residual stress, strain relieved around the hole is function of magnitude of stress, patterns of stress distribution and hole geometry of diameter and depth. Relieved strain coefficients can be calculated from FEM analysis of relieved strain and actual stress. These relieved strain coefficients make it possible to measure residual stress which vary along the depth in the subsurface of stressed material. In this study, the calibration tests of residual stress measurement are carried out by drilling a hole incrementally on the cantilever or on the tensile test bar. Residual stresses can be determined from measured strains around a shallow hole by application of power series method. For the sake of reliable measurement of residual stress, much efforts should be done to measure relieved strains and hole depth more accurately comparing with conventional procedures of gage subject to the external load. Otherwise linear equations converting strains into stresses may yield erratic residual stresses because of ill-conditions of linear equations. With accurate measurements of relieved strains, residual stress even if varying along the depth can be measured. It is also possible to measure residual stress in the thin film of material by drilling a shallow hole.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.5
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• pp.590-597
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• 1985

A recursive geometric adaptive control method to compensate for machining straightness error in the finished surface due to tool deflection and guideway error generated by end milling process is developed. The relationship between the tool deflection and the feedrate is modeled by a modified Taylor's tool life equation. Without a priori knowledge on the variations off cutting parameters, time varying parameters are then estimated by an exponentially windowed recursive least squares method with only post-process measurements of the straightness error. The location error is controlled by shifting the milling bed in the direction perpendicular to the finished surface and adding a certain amount of feedrate with respect to the tool deflection model before cutting. The waviness error is compensated by adjusting the feedrate during machining. Experimental results show that location error is controlled within a range of fixturing error of the bed on the guideway and that about 60% reduction in the waviness error can be achieved within a few steps of parameter adaption under wide operating ranges of cutting conditions even if the parameters do not converge to fixed values.