• Journal of the Chungcheong Mathematical Society
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• v.37 no.1
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• pp.27-40
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• 2024

In this paper, we consider the higher-order HartreeFock equations. The higher-order linear Schrödinger equation was introduced in [5] as the formal finite Taylor expansion of the pseudorelativistic linear Schrödinger equation. In [13], the authors established global-in-time Strichartz estimates for the linear higher-order equations which hold uniformly in the speed of light c ≥ 1 and as their applications they proved the convergence of higher-order Hartree-Fock equations to the corresponding pseudo-relativistic equation on arbitrary time interval as c goes to infinity when the Taylor expansion order is odd. To achieve this, they not only showed the existence of solutions in L² space but also proved that the solutions stay bounded uniformly in c. We address the remaining question on the convergence of higherorder Hartree-Fock equations when the Taylor expansion order is even. The distinguished feature from the odd case is that the group velocity of phase function would be vanishing when the size of frequency is comparable to c. Owing to this property, the kinetic energy of solutions is not coercive and only weaker Strichartz estimates compared to the odd case were obtained in [13]. Thus, we only manage to establish the existence of local solutions in H^s space for s > $\frac{1}{3}$ on a finite time interval [-T, T], however, the time interval does not depend on c and the solutions are bounded uniformly in c. In addition, we provide the convergence result of higher-order Hartree-Fock equations to the pseudo-relativistic equation with the same convergence rate as the odd case, which holds on [-T, T].

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.2 no.3
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• pp.33-60
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• 2007

This study alms to analyze the entrepreneur characteristics of founder on enterprise performance from the strategic viewpoint as well as features of founder of small firms such as background feature of founder, psychological features and management skill. As considered by Background features of founder include educational background of founder, his experience in business creation, consultation or course related to business creation. This study verified the effects of factor which business performance (financial, non financial) on small firms. Also, this study considered psychological features of founder include achievement desire, risk-free propensity, level of patience on vagueness and control position. And it analyzed that between such factors and performance of small firms were examined in related. In the mean time, management ability of founder, entrepreneur ability, technical and function ability were considered for management skill of founder and alalyzed effect of the factors on performance of small firm were examined. Effects of strategic intention of founder of small firm were analyzed by the strategic viewpoint. At this time, strategy of small firm was divided into product-service reform differentiation strategy, marketing differentiation strategy and cost leadership strategy. This study distributed questionnaire on CEO of small firms in Daejeon and Chungnam area for accomplish the study objective and it collected a total of 145 copies of questionnaires. As a result of analyzing collected questionnaire, this study deduced the following study results and suggestions. First, results different from those of existing studies were found Since sales, net income and profit rate of small firm were not high cause economic depression on the whole. Second, entrepreneur ability was found to be required for success of business creation. Entrepreneur ability of founder was the factor that affects both financial and non - financial performance of small firm. As such, entrepreneur ability can be regarded as the most important factor for success in business creation of small firm. Accordingly, entrepreneur ability is the most important source for success in business creation of small firm. Third, strategy of small firm was found to be the important factor that affects the non-financial performance even if it could not give significant effects on financial performance. Thus, product service reform differentiation strategy, marketing differentiation strategy and cost leadership strategy have significant effects on non - financial performance of small firm. Accordingly, it is required to operate small firm with strategic mind - set for small firm to achieve success. This study analyzed the effects of feature of founder and strategy of small firm on business performance of small firm through practical analysis on small firms in Daejeon and Chungnam area, and deduced meaningful results. However, Since this study collected data on small firms in Daejeon and Chungnam only, there is a limit in generalizing the results of this study to all small firms in Korea. Companies answering to this questionnaire process were mainly wholesale and retail service companies. In addition, there is a limit in that it failed to analyze feature of representative type of industry due to limit in number of sample, it is required to divide representative type of industry and to compare and analyze types of industry in future studies.

• Korean Journal of Occupational Health Nursing
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• v.4
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• pp.58-83
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• 1995

The small scale industries which have less than 30 employees occupy 86.5% of total number of industries in Korea. And though they have higher accident rate and lower environmental condition than big industries, it has been not mandatory to appointing health care manager at factory. So, from 1993, government subsidizes to the health care management of small industries. The purpose of this study is to identify the real feature of health care status in small industries, and to evaluate the level of health care management, before and after the subsidiary program. 65 small plating industries which have been managed by the same health care management support institution in 1993 were selected for study. Of the 65 industries, 3 which have not taken both environmental evaluation and health screening in 1994, and 9 which have closed were excluded from study sample. And the remaining 53 were analyzed by using the results of environmental evaluation and health screening, reported to the Ministry of Labor, before and after the subsidiary program, the analysis was done by the comparison of the two year paired data of the same industry. Over-permissible-limit rate, health screening implementation rate, above grade C rate were calculated and compared. The status of health care management ; 1. Of the sample industries, 96.9% provide protective equipment and 80.0% set up ventilating system. Protective gloves (89.2%) and protective clothing (80.0%) are widely provided, but ear plugs (4.6%) are rarely provided. 21.5% of the protective equipment are well put on, and 40.4% of the ventilating systems function well. 2. In 1993, 35 industries, 53.8% of the sample, checked working environment twice. Over-permissible-limit rates of heavy metal (12.2%), suspended particle (11.1%), noise (5.5%) were high. To put on protective equipment and to set up local ventilating system were pointed out by the examiners. 3. General health screening was done at 63.1% of the sample industries and 35.3% of total workers were examined. Specific health screening was done at 93.8% of the sample industries and 75.4% of workers were examined. 15.5% of workers was provided to be above grade C and to have digestive system disease (43.3%), circulatory disease (18.9%), and hematopoietic disease (14.2%), etc. 4. In 1993, the subsidiary program of health care management was provided in forms of health education, health counseling, and rounding check of working field. And 61.5%, 83.0%, 55.4% of sample industries respectively received it. The average visit per industry was 1.8. Comparisons of the level of occupational health before and after the subsidiary program ; 1. Over-permissible-limit rates of hazardous factors of 1993 and that of 1994 were compared. The rates of suspended particle, noise, organic solvent of 1994 (37.5%, 13.4%, 24.2% respectively) were higher than that of 1993 (25.0%, 6.0%, 6.3% respectively). In the case of acid, there was no difference between the rate of 1993 and that of 1994. Only the rate of heavy metal decreased from 12.9% in 1993 to 3.0% in 1994. 2. General health screening was done at 38.7% of the sample industries in 1993 and at 44.6% in 1994. But the implementation rate of specific health screening decreased from 72.4% in 1993 to 64.6% in 1994. 3. The implementation rate of specific health screening was analyzed by some health factors. The rate of suspended particle increased from 61.8% in 1993 to 91.2% in 1994. But the rates of the others-noise, organic solvent, heavy metal, specific chemical substances-decreased. 4. Above grade C rate in health screening increased from 27.8% in 1993 to 35.5% in 1994. But that of endocrine disorders and pulmonary disease decreased.

• Journal of KIISE:Computer Systems and Theory
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• v.37 no.2
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• pp.66-75
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• 2010

This paper proposes an efficient method for design and implementation of the artificial intelligence (AI) of 'omok' game on the GPU. The proposed AI is designed on a cooperative structure using min-max game tree and genetic algorithm. Since the evaluation function needs intensive computation but is independently performed on a lot of candidates in the solution space, it is computed on the GPU in a massive parallel way. The implementation on NVIDIA CUDA and the experimental results show that it outperforms significantly over the CPU, in which parallel game tree and genetic algorithm on the GPU runs more than 400 times and 300 times faster than on the CPU. In the proposed cooperative AI, selective search using genetic algorithm is performed subsequently after the full search using game tree to search the solution space more efficiently as well as to avoid the thread overflow. Experimental results show that the proposed algorithm enhances the AI significantly and makes it run within the time limit given by the game's rule.

• Advances in aircraft and spacecraft science
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• v.5 no.2
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• pp.225-237
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• 2018

The difficulties of satellite vibration testing are due to the commonly expressed qualification requirements being incompatible with the limited performance of the entire controlled system (satellite + interface + shaker + controller). Two features cause the problem: firstly, the main satellite modes (i.e., the first structural mode and the high and low tank modes) are very weakly damped; secondly, the controller is just too basic to achieve the expected performance in such cases. The combination of these two issues results in oscillations around the notching levels and high amplitude beating immediately after the mode. The beating overshoots are a major risk source because they can result in the test being aborted if the qualification upper limit is exceeded. Although the abort is, in itself, a safety measure protecting the tested satellite, it increases the risk of structural fatigue, firstly because the abort threshold has been already reached, and secondly, because the test must restart at the same close-resonance frequency and remain there until the qualification level is reached and the sweep frequency can continue. The beat minimum relates only to small successive frequency ranges in which the qualification level is not reached. Although they are less problematic because they do not cause an inadvertent test shutdown, such situations inevitably result in waiver requests from the client. A controlled-system analysis indicates an operating principle that cannot provide sufficient stability: the drive calculation (which controls the process) simply multiplies the frequency reference (usually called cola) and a function of the following setpoint, the ratio between the amplitude already reached and the previous setpoint, and the compression factor. This function value changes at each cola interval, but it never takes into account the sensor signal phase. Because of these limitations, we firstly examined whether it was possible to empirically determine, using a series of tests with a very simple dummy, a controller setting process that significantly improves the results. As the attempt failed, we have performed simulations seeking an optimum adjustment by finding the Least Mean Square of the difference between the reference and response signal. The simulations showed a significant improvement during the notch beat and a small reduction in the beat amplitude. However, the small improvement in this process was not useful because it highlighted the need to change the reference at each cola interval, sometimes with instructions almost twice the qualification level. Another uncertainty regarding the consequences of such an approach involves the impact of differences between the estimated model (used in the simulation) and the actual system. As limitations in the current controller were identified in different approaches, we considered the feasibility of a new controller that takes into account an estimated single-input multi-output (SIMO) model. Its parameters were estimated from a very low-level throughput. Against this backdrop, we analyzed the feasibility of an LQG control in cancelling beating, and this article highlights the relevance of such an approach.

• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.176-183
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• 2001

Loblolly pine (Pinus taeda L.) is the most economically important timber producing species in the southern United States. Much attention has been given to predicting diameter distributions for the solution of multiple-product yield estimates. The three-parameter Weibull diameter distribution yield prediction systems were developed for loblolly pine plantations. A parameter recovery procedure for the Weibull distribution function based on four percentile equations was applied to develop diameter distribution yield prediction models. Four percentiles (0th, 25th, 50th, 95th) of the cumulative diameter distribution were predicted as a function of quadratic mean diameter. Individual tree height prediction equations were developed for the calculation of yields by diameter class. By using individual tree content prediction equations, expected yield by diameter class can be computed. To reduce rounding-off errors, the Weibull cumulative upper bound limit difference procedure applied in this study shows slightly better results compared with upper and lower bound procedure applied in the past studies. To evaluate this system, the predicted diameter distributions were tested against the observed diameter distributions using the Kolmogorov-Smirnov two sample test at the ${\alpha}$=0.05 level to check if any significant differences existed. Statistically, no significant differences were detected based on the data from 516 evaluation data sets. This diameter distribution yield prediction system will be useful in loblolly pine stand structure modeling, in updating forest inventories, and in evaluating investment opportunities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.296-313
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• 1982

At a time when world population and food supply are in a delicate balance, it is essential that we look at factors to improve this balance. We can alter the environment to better fit the plant's needs, or we can alter the plant to better fit the environment. Improved technology has allowed us to increase the yield level. For moderately detrimental weather events technology has generally decreased the yield variation, yet for major weather disasters the variation has increased. We have raised the upper level, but zero is still the bottom level. As we concentrate the production of particular crops into limited areas where the environment is closest to optimum, we may be increasing the risk of a major weather related disaster. We need to evaluate the degree of variability of different crops, and how weather and technology can interact to affect it. The natural limits of crop production are imposed by important ecological factors. Production is a function of the climate, the soil, and the crop and all activities related to them. In looking at the environment of a crop we must recognize these are individuals, populations and ecosystems. Under intensive agriculture we try to limit the competition to one desired species. The environment is made up of a complex of factors; radiation, moisture, temperature and wind, among others. Plant response to the environment is due to the interaction of all of these factors, yet in attempting to understand them we often examine each factor individually. Variation in crop yields is primarily a function of limiting environmental parameters. Various weather parameters will be discussed, with emphasis placed on how they impact on crop production. Although solar radiation is a driving force in crop production, it often shows little relationship to yield variation. Water may enter into crop production as both a limiting and excessive factor. The effects of moisture deficiency have received much more attention than moisture excess. In many areas of the world, a very significant portion of yield variation is due to variation in the moisture factor. Temperature imposes limits on where crops can be grown, and the type of crop that can be grown in an area. High temperature effects are often combined with deficient moisture effects. Cool temperatures determine the limits in which crops can be grown. Growing degree units, or heat accumulations, have often been used as a means of explaining many temperature effects. Methods for explaining chilling effects are more limited.

• Ocean and Polar Research
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• v.33 no.4
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• pp.473-483
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• 2011

In the recent WTO/DDA negotiations, discussions are progressing to forbid fishery subsidies which have negative effect on the natural environment and the fishery resources and to lower or to eliminate the tariff/non-tariff barriers that distort trade liberalization. As a result, linking to the weak structural environment of Korea's fishing villages; such a scheme has jeopardized the livelihood of fishermen who settle down in local fishing harbors. Against this backdrop, the government is attempting to positively respond to changes in the fishing environment in a number of different ways: promotion of fishing tourism, fishing harbor reinforcement in function, developing fishing villages, and harbors. With respect to investment by priority in fishing harbor development, it is very important to appropriately select investment targets based on objective criteria. A small number of harbors are chosen and investment plans by harbor are systematically devised, economic feasibility and the effects of investment are analyzed and reviewed in relation to each target harbor. This paper is designed to review and assess objective evaluation methods and the degree of importance for the designation of target harbors, dealing with local harbors in Chung Nam Do as a model. Each local government has tried to reorganize existing harbors and develop new harbors, considering a fall in the number of fishing vessels and the expansion of maritime leisure activities. In order to overcome the limit of existing harbors in function, to raise the income of fishermen, and to activate tourism, they have shifted their focus from simple functions such as vessel evacuation and anchoring to harbor beautification, which can work as a basis for fishing tourism. This paper points out that the AHP analysis method for prioritizing local harbors in Chung Nam Do should help to be chosen target harbors in other cities and provinces. Each local government has attempted to reorganize existing harbors and to develop new harbors, taking into consideration the decline in the number of fishing vessels and the expansion of maritime leisure activities. In order to overcome the limited number of functional harbors, to raise the income of fishermen, and to boost tourism, they have shifted their focus from simple functions, such as vessel evacuation and anchoring, to harbor beautification, which can work as a basis for fishing tourism. This paper shows that the AHP analysis method for prioritizing local harbors in Chungcheongnam-do could aid in the effective selection of target harbors in other cities and provinces.

• Journal of the Korean Institute of Landscape Architecture
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• v.34 no.3 s.116
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• pp.104-119
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• 2006

The eastern rear business complex of the Gwangyang Harbor (second stage) has undergone the 'alternative bid' process by which a construction company is selected based on their suggestions for an alternative plan and the bid for the construction expenses is based on the previously completed original plan, thereby implicitly accepting the arrangement and scale of the park which was presented in the original plan. It is possible, however, that the concept and plan of each park needs to be approached in a new way within the extent of given design guidelines. This study focuses on the alternative plan process and the Symbol Park (the second neighborhood park) and Waterfront Park (the third neighborhood park) among the five neighborhood parks in the eastern rear business complex (second stage). These two parks provide scale and function for the structure of the park and greenways system at the eastern rear complex. The neighboring waterway is a significant resource for emphasizing the pre-development features of the site. The alternative plan process focuses on determining the resources for the park's plan based on the environmental analyses of the site and utilizing the results. That is, through an analysis of the current state, all available resources are determined and the facilities and activities are derived based on these results. By this, Symbol Park and Waterfront Park reflect the regional features of the eastern rear complex, and these parks will feasibly perform the role of the region's key parte. The limit of this study is the fact that there is no chance for landscape architecture to actively play a role in the creation of the master plan, land utilization plan, and plan for the complex. Therefore there is a problem that the function scale and location of the park are not distributed appropriately in the rear complex. Also the plan for protecting the waterway's shore, a significant resource, only considers the structural stability of the engineering works, degrading the visual and ecological quality. These experiences will be used as a case for further designing the industrial complex and for the resulting park plan.

• Investigative Magnetic Resonance Imaging
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• v.4 no.1
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• pp.14-19
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• 2000

Purpose : This study was to present the functional brain mapping of both functional magnetic resonance imaging(MRI) and transcranial magnetic stimulation(TMS) in a case of schizencephaly. Materials and methods : A 28-year-old man, who had left hemiplegia and schizencephaly in right cerebral hemisphere, was exacted with both functional MRI and TMS. Motor function of left hand was decreased whereas right hand was within normal limit. For functional MRI, gradient-echo echo planar imaging($TR/TE/{\alpha}$=1.2 sec/90 msec/90) was employed. The paradigm of motor task consisted of repetitive self-paseo hand flexion-extension exercises with 1-2 Hz periods. An image set of 10 slices was repetitively acquired with 15 seconds alternating periods of task performance and rest and total 6 cycles (three ON periods and three OFF periods) were performed. In brain mapping, TMS was performed with the round magnetic stimulator (mean diameter; 90mm). The magnetic stimulation was done with 80% of maximal output. The latency and amplitude of motor evoked potential(MEP)s were obtained from both abductor pollicis brevis(APB) muscles. Results : Functional MRI revealed activation of the left primary motor cortex with flexion-extension exercises of healthy right hand. On the other hand, the left primary motor cortex, left supplementary motor cortex, and left promoter areas were activated with flexion-extension exercises of left hand. In TMS, magnetic evoked potentials were induced in no areas of right cerebral hemisphere, but in 5 areas of left corebral hemisphere from both abductor pollicis brevis. Latency, amplitude, and contour of response of the magnetic evoked potentials in both hands were similar. Conclusion : Functional MRI and TMS in a patient with schizencephaly were successfully used to localize cortical motor function. Ipsilateral motor pathway is thought to be secondary to reinforcement of the corticospinal tract of the ipsilateral motor cortex.