• Proceedings of the Korean Society for Rock Mechanics Conference
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• 2000.09a
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• pp.201-210
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• 2000

Rock bridge in rock masses can be considered as one of several types of opening-mode fractures, and also it has been known to have a great influence on the stability of structures in rock mats. In the beginning of researching a rock bridge it used to be studied only in characteristics of its behavior, as considering resistance of material itself. However the distribution pattern of rock bridges, which can affect the stability of rock structures, is currently researched with a fracture mechanical approach in numerical studies. For investigating the effect of rock bridges on the development pattern of hydraulic fractures, the author analyzed numerically the stress state transition in rock bridges and their phenomena with a different pattern of the rock bridge distributons. From the numerical studies, a two-crack configuration could be defined to be representative of the most critical conditions for rock bridges, only when cracks are systematic and same in their length and angle. Moreover, coalescence stresses and onset of propagation stresses could be known to increase with decreasing s/L ratio or increasing d/L ratio. The effect of pre-existing crack on hydraulic fracturing was studied also in numerical models. Different to the simple hydraulic fracturing modeling in which the fractures propagated exactly parallel to the maximum remote stress, the hydraulic fractures with pre-existing cracks dial not propagate parallel to the maximum remote stress direction. These are representative of the tendency to change the hydraulic fractures direction because of the existence of pre-existing crack. Therefore s/L, d/L ratios will be identical as a function effective on hydraulic fractures propagation, that is, the $K_{I}$ vague increase with decreasing s/L ratio or increasing d/L ratio and its magnification from onset to propagation increases with decreasing s/L ratio. The scanline is a commonly used method to estimate the fracture distribution on outcrops. The data obtained from the scanline method can be applied to the evaluation of stress field in rock mass.s.

• Tunnel and Underground Space
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• v.10 no.3
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• pp.447-456
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• 2000

Rock bridge in rock masses can be considered as one of several types of opening-mode fractures, and also it has been known to have a great influence on the stability of structures in rock mass. In the beginning of researching a rock bridge it used to be studied only in characteristics of its behavior, as considering resistance of material itself. However the distribution pattern of rock bridges, which can affect the stability of rock structures, is currently researched with a fracture mechanical approach in numerical studies. For investigating the effect of rock bridges on the development pattern of hydraulic fractures, the author analyzed numerically the stress state transition in rock bridges and their phenomena with a different pattern of the rock bridge distributions. From the numerical studies, a two-crack configuration could be defined to be representative of the most critical conditions for rock bridges, only when cracks are systematic and same in their length and angle. Moreover, coalescence stresses and onset of propagation stresses could be known to increase with decreasing s/L ratio or increasing d/L ratio. The effect of pre-existing crack on hydraulic fracturing was studied also in numerical models. Different to the simple hydraulic fracturing modeling in which the fractures propagated exactly parallel to the maximum remote stress, the hydraulic fractures with pre-existing cracks did not propagate parallel to the maximum remote stress direction. These are representative of the tendency to change the hydraulic fractures direction because of the existence of pre-existing crack. Therefore s/L, d/L ratios will be identical as a function effective on hydraulic fractures propagation, that is, the K$_1$ value increase with decreasing s/L ratio or increasing d/L ratio and its magnification from onset to propagation increases with decreasing s/L ratio. The scanline is a commonly used method to estimate the fracture distribution on outcrops. The data obtained from the scanline method can be applied to the evaluation of stress field in rock mass.

• Economic and Environmental Geology
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• v.40 no.5
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• pp.651-660
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• 2007

Acid drainage has been recognized as an environmental concern in abandoned mine sites for long time. Recently, the environmental and structural damage by acid drainage is a current issue in construction sites in Korea. Here, the author introduces the type of damages by acid drainage in construction sites and emphasizes the importance of geoscience discipline in solving the problem. Metasedimentary rock of Okcheon group, coal bed of Pyeongan group, Mesozoic volcanic rock. and Tertiary sedimentary and volcanic rocks are the major rock types with a high potential for acid drainage upon excavation in Korea. The acid drainage causes the acidification and heavy metal contamination of soil, surface water and groundwater, the reduction of slope stability, the corrosion of slope structure, the damage on plant growth, the damage on landscape and the deterioration of concrete and asphalt pavement. The countermeasure for acid drainage is the treatment of acid drainage and the prevention of acid drainage. The treatment of acid drainage can be classified into active and passive treatments depending on the degree of natural process in the treatment. Removal of oxidants, reduction of oxidant generation and encapsulation of sulfide are employed for the prevention of acid drainage generation.

• Korean Journal of Microbiology
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• v.38 no.3
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• pp.153-161
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• 2002

Sox4, a transcription factor, consists of three functional domains: an HMG-box domain as a DNA binding domain, serine rich region as a transactivation domain and glycine rich region (GRR), an unknown functional domain. Although Sox4 is known to be functionally involved in heart, B-cell and reproductive system development, its physiological function remains to be elucidated. We used pGEX expression system to develop a simple and rapid method for purifying Sox4 protein in suitable forms for biochemical studies of their functions. Unexpectedly, we observed that full-length Sox4 appears to be protease-sensitive during expression and purification in E. coli. To map the protease-sensitive site in Sox4, we generated various constructs with each of functional domains of Sox4 and purified as the GST-Sox4 fusion proteins using glutathione beads. We found that the specific cleavage site for the proteolytic enzyme, which exists in E. coli, is localized within the novel GRR of Sox4. Our study suggest that the GRR of Sox4 may a target for the cellular protease action and this cleavage in the GRR may be involved in regulating physiological function of Sox4. Additionally, our study may provide a useful method for investigating the proteolytic cleavage of the target molecule in E. coli.

• Korean Journal of Poultry Science
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• v.16 no.2
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• pp.105-127
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• 1989

Although poultry industry in Japan has been much developed in recent years, it still needs to be developed , compared with developed countries. Since the poultry market in Korea is expected to be opened in the near future it is necessary to maximize the Productivity to reduce the production costs and to develop the scientific, technologies and management organization systems for the improvement of the quality in poultry production. Followings ale the summary of poultry industry in Japan. 1. Poultry industry in Japan is almost specized and commercialized and its management system is ： integrated, cooperative and developed to industrialized intensive style. Therefore, they have competitive power in the international poultry markets. 2. Average egg weight is 48-50g per day (Max. 54g) and feed requirement is 2. 1-2. 3. 3. The management organization system is specialized and farmers in small scale form complex and farmers in large scale are integrated.

• International Journal of Highway Engineering
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• v.1 no.1
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• pp.107-119
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• 1999

The joints in the jointed concrete pavement provide a control against transverse or longitudinal cracking at slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random cracks cause more serious distresses and result in structural or functional failure of pavement system. However, joints nay cause distresses due to its inherent weakness in structural integrity. Thus, the evaluation at joint is very important. and the joint-related distresses should be evaluated reasonably for economic rehabilitation. The purpose of this paper was to develop an evaluation system at joints of jointed concrete pavement using finite element analysis program, ILLI-SLAB, and nondestructive testing device. FWD. To develop an evaluation system for JCP, a sensitivity analysis was performed using ILLI-SLAB program with a selected variables which might affect fairly to on the performance of transverse joints. The most significant variables were selected from precise analysis. An evaluation charts were made for jointed concrete pavement by adopting the field FWD data. It was concluded that the variables which most significantly affect to pavement deflections are the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G), and limiting criteria on the performance of joints at JCP are 300pci. 500,000 lb/in. respectively. Using these variables and FWD test, a charts of load transfer ratio versus surface deflection at joints were made in order to evaluate the performance of JCP. Practically, Chungbu highway was evaluated by these evaluation charts and FWD field data for jointed concrete pavement. For Chungbu highway, only one joint showed smaller value than limiting criterion of the modulus of dowel/concrete interaction(G). The rest joints showed larger values than limiting criteria of the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G).

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.664-671
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• 2019

This study was conducted to investigate the environmental impact of the construction of the Yeongju Dam, located near the upper stream of the Nakdong River, on benthic macroinvertebrates. The investigation was conducted four times from 2015 to 2016 and the composition of the benthic macroinvertebrate fauna from the four surveyed sites was compared. After the dam construction, the number of benthic macroinvertebrate species decreased and the species composition ratio of the E.P.T taxa(Ephemeroptera, Plecoptera, and Trichoptera) decreased, which favored the previous environment and the large riverbed structure. However, the species composition ratio of the O.C.H taxa (Odonata, Coleoptera, and Hemiptera), which favored the reservoir environment, increased. For the pattern of changes in the functional habitat groups, the proportion of 'Clinger(CL)' taxa decreased and the 'Burrower(BU), Climber(CB), Sprawler(SP), Swimmer(SW)' taxa increased in all surveys after the dam construction. A cluster stability comparison showed that the 'Stability Group II' species of St.2 and St.3 showed a drastic decrease. The average Benthic Macroinvertebrate Index(BMI) of all the survey sites in 2016 was lower than that in 2015. This research confirmed the temporal and spatial changes in the habitat type and community structure of the benthic macroinvertebrates resulting from the dam construction.

• Management & Information Systems Review
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• v.35 no.4
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• pp.251-268
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• 2016

The present study has the purpose of analyzing the relationship between entrepreneurial characteristics and success factors of small-scale start-up founders as well as the relationship between success factors and performances of start-up businesses. It is also aimed in this study to determine the structural effects of start-up founders' characteristic upon their performances and by thus, to provide those who prepare for and/or have been operating start-up business with suggestions for stable and successful start-up as well operation. The study resulted in the following outcomes: First, the analysis of the relationship between characteristics and success factors of start-up business found that the empirical characteristics of small-scale start-up business founders might influence every factor for their success including the financial conditions as well as management of shops, products and service. Their psychological characteristics, however, turned out to have influence upon the management of products and service only, but not upon the financial conditions and management of shops, a result implying that the higher desire and creativity small-scale start-up business founders have, the more probable the start-up businesses become successful. Second it was learned from the analysis of the relationship between success factors and performances of start-up businesses that such success factors of start-ups as financial conditions as well as management of shops, products and service could exercise impact upon their performances, signifying that the exact decision making of small-scale start-up founders might affect the performances of small-scale start-up businesses. Third, the analysis of the relationship between entrepreneurial characteristics and performances of start-up founders revealed that both empirical and psychological characteristics of start-up founders might have influence upon the performances of start-up businesses, leading to the conclusion that small-scale start-up founders could achieve higher performances in their start-up when they are highly aware of empirical and psychological characteristics for start-up as part of entrepreneurial characteristics.

• Korean Journal of Heritage: History & Science
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• v.44 no.4
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• pp.56-69
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• 2011

A Gamsil is an ritual instrument which enshrine the ancestral tablets of four lines from late great-great-grandfather and grandmother to late father and mother. This has their soul. Juja's "Garye" informs its structure pattern. It is placed in Sadang and takes the form of a perfectly square box. It partitions four rooms and enshrine an ancestral tablet room by room. They get the ancestral tablets line up from west to east. And they also enshrine the ancestral tablets without his descendant together in Gamsil. A Gamsil is a space to enshrine the ancestral tablets and to place an order within a family. A social status and A family economic power become a standard in making and managing Sadang. Kingdom in Joseon period limited the ancestral tablets considering of his degree of official rank which descendant enshrined. A official servant can be stable economically in getting a stipend and build sadang in the house. While household a little in economic enshrine the ancestral tablets at a Gamsil placed at the a space of private home. His personal circumstances make size and pattern, place change in relation to Gamsil. A Gamsil looks like house in structure and pattern. It has the immortality of the soul. And it changed from a table size to a ancestral tablet size. This Gamsil is comfortable to move and is made considering of the width and height of household. The transition of Gamsil means institutions is in close to a family economic power in social change. Kingdom in Joseon early period makes a policy of a Gamyo's build and an ancestral enshrine in basement of Juja's "Garye". The transition of Gamsil gave a common people limitted socially and institutionally the service of late four lines. Most of people enshrine the ancestral tablets of their four lines in approaching of in the late of Joseon Dinasty. They compromise on their reality and cause. The transition of Gamsil implied many different things in social ; the authenticity search and a dignity expression of his family, the foundation for the diffusion of an ancestral service, a space sharing with ancestor and descendent, the increment of a family economic power etc.

• Journal of Ethics
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• no.97
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• pp.279-306
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• 2014

This study presents the leadership model that is to build of ethical and cultural leadership. This model is to operat the functions of a systemof leadership that based on the universal principles of life, that is performed bybalance and harmonized judgment of the ideal ethical oughtfulness and cultural values, and practise ethically through relationship, process, and skill of leadership. And this model turn out to lead a real impact and then overcome conflict, problem solving, motivation. To check the validity of leadership, this study analysis the case study of leadership of King Sejong. His leadership is based at heaven that on the basis of the universal principles of life. The ideal ethical oughtfulness is to cares for people and the value of the cultural is to cherish the people's will. His leadership is to be balance and harmonized judgment of the ideal ethical oughtfulness and the cultural values by practice of virtues through relationship, process, and skill of leadership. Leadership relationship is a equal role relationship that are the children of the sky, thus to be coexistence and harmonyin close collaboration. Leadership process is a process of transvaluation to ensure the validity of the values by rational discussion and persuasion. Leadership skills led to active obedience through leading by example and love of learning. King Sejong' leadership is the leadership that ethical and cultural leadership become well-implemented.