• Korean Journal of Environment and Ecology
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• v.35 no.1
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• pp.48-67
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• 2021

Plant species exhibit current characteristics as a result of interactions with environmental conditions. The plants of Viola sp. have selected chasmogamous flowers with vigorous vegetative propagation or development of cleistogamous flowers as an adaptation strategy. Viola websteri is distributed on the Korean peninsula and the eastern part of Jilin Province, China. The center and edge of the distribution are expected to exhibit different population-dynamics. It is necessary to investigate the cause of its current limited distribution even though V. websteri has a mixed-mating strategy. Firstly, We examined the vegetation environment of habitats and evaluated its characteristics. Growth characteristics were examined through plant phenology. We then evaluated the population structure, characteristics of chasmogamous flowers, and productivity of cleistogamous flowers. Moreover, we compared population sizes between 2014 and 2018. Most habitats were located in deciduous broadleaf mixed forests adjacent to valleys. V. websteri produced chasmogamous flowers with self-incompatibility in April-May and cleistogamous flowers in June-September. The cleistogamous flower production is a strategy ensuring seed production under uncertain environmental fluctuations; these were approximately twice as numerous as chasmogamous flowers. The population structure was distinguished into stable and very unstable regions. There were sites where the population experienced a sharp decline in the 2018 compared to that of 2014. This large decline was found in the edge populations. The habitats had different microsites depending on the natural disturbances of drought and the matrix constituting the habitat, thus supporting various plants. Ensuring the production of seeds through cleistogamous flowers, it was determined that rapid seedling re-establishment and population replenishment were possible when the natural disturbance factor was removed. Environmental factors did not equally affect all populations or individuals. Therefore, it was expected that it would be able to persisted in a long time, despite the rapid decrease in the number of individuals in the population regionally. Local extinction and re-establishment are likely to repeat according to environmental change. We propose the additional population investigation based on this works are required. We also suggest a need to assess the long-term population dynamics and the genetic characteristics of chasmogamous flowers and cleistogamous flowers to establish and implement effective conservation strategies.

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.355-373
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• 1995

Craniofacial region is a musculodentoskeletal system that consists of many anatomical structures ; cranioskeletal structures, dental arches, and formation and functions of masticatory muscles have close correlations. Growth and development of craniofacial region are influenced by not only hereditory factors, but also environmental factors such as craniofacial muscles and surrounding tissues. On the contrary, however, study on changes in functions or adaptations of craniofacial muscles following changes of craniofacial skeletal structures has been somewhat insufficient. The author's purpose was to observe correlations between masticatory muscular functions and change patterns according to cranial skeletal structures and occlusion patterns, for this, comparative study of muscle activity changes of preand post- orthognathic surgery states in skeletal Cl III malocclusion patients was peformed. The selected sample groups were 15 normal male patients, 15 skeletal Cl III pre-orthognatic surgery patients and 15 skeletal Cl III post-orthognatic surgery patients. For each sample groups, cephalometric x-ray taking, masticatory efficiency test and measurements of muscle activities in anterior temporal muscle, masseter and upper lip in rest, clenching, chewing and swallowing were carried out. The following results were obtained : 1. In resting state of mandible, pre-surgery malocclusion group showed higher m. activities in ant. temporalis, masseter and upper lip than post-surgery group. Post-surg. malocc. group showed significantly high m. activity only in upper lip compared to the normal group. 2. In clenching state, post-surg. malocc. group showed higher m. activities in ut. temporalis, masseter and upper lip than pre-surg. malocc. group. 3. In chewing state, post-surg. malocc. group showed higher m. activities in ant. temporalis and masseter than pre-surg. malocc. group, on the other hand, decreased upper lip activity was noticed. 4. In swallowing state, post-surg. malocc. group showed lower upper lip activity than pre-surg. malocc. group but higher than that of the normal group. No significant difference in m. activities of ant, temporalis and masseter was noticed among the three groups. 5. Masticatory efficiency was lower in pre-surg. malocc. group than normal group, masticatory efficiency showed an increase in post-surg. malocc. group compared to the pre-surg. malocc. group. However, both groups showed significant differences compared to the normal group.

• Journal of the Korean Geosynthetics Society
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• v.12 no.4
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• pp.11-19
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• 2013

Recently despite the development of analysis program and construction technologies, collapse at the many earth retaining wall construction site of the structure due to the economic and human damage has occurred. The results of geothechnical investigation studies field, it was found to differ from the results of the original design. There may be errors parameters calculated from the results of ground investigation in such a case. And it can be estimated that it is irrational to behavior analysis of the earth retaining wall were analyzed by utilizing the parameters. And in this study, parameters that affect the earth retaining wall the correlations were analyzed using elasto-plastic method. Analysis method was changed various parameters (cohesion, subgrade reaction coefficient, load condition) applied to the elasto-plastic method. And due to a change in the behavior of earth retaining wall materials were analyzed. As a result, the cohesion greatly affects the behavior of earth retaining wall materials in various parameters. For this reason, the results of the geothechnical investigation, confirmation of the actual ground is very important in the design of the earth retaining wall. And, calculating accurate and reasonable of the cohesion of the various parameters is very important.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.2
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• pp.130-137
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• 2017

Due to the economic growth and development of construction technology, a role of foundation to resist heavy loads has been increased. In this present study to improve the structural performance of reinforced concrete pile, the precast HPC pile reinforced with rebar and filling concrete was developed and the strength of pile was predicted based on the limit state design method. The safety of HPC pile strength was evaluated by comparing with the design values. The geometry of HPC pile is a decagon cross section with a maximum width of 500 mm and a minimum width of 475 mm, and the hollow head of pile thickness is 70 mm. The inner area of the hollow head part was made as the square ribbed shape presented in the limit state design code in order to achieve horizontal shear strength between pile concrete and filling concrete. From the shear test results, it was found that the stable shear strength were secured without abrupt failure until maximum load stage despite the shear cracks was found. Shear strength is 135% and 119% higher than that of design value calculated from limit state design code. The driving test results of HPC pile according to the presence of additional reinforcement showed the outstanding crack resistance against impact loads condition. From the bending test results the flexural load between PHC pile and HPC pile was 1.51 times and 1.48 times higher than that of the design flexural load of conventional PHC pile.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.2
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• pp.151-159
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• 2015

In this study, experimental research was carried out to evaluate and improve the seismic performance of reinforced concrete beam-column joint regions using strengthening materials (CFRP sheet, AFRP sheet, embedded CFRP rod) in existing reinforced concrete structure. Therefore it was constructed and tested seven specimens retrofitting the beam-column joint regions using such retrofitting materials. Specimens, designed by retrofitting the beam-column joint regions of existing reinforced concrete structure, were showed the stable failure mode and increase of load-carrying capacity due to the effect of crack control at the times of initial loading and confinement of retrofitting materials during testing. Specimens LBCJ-CRUS, designed by the retrofitting of CFRP Rod and CFRP Sheet in reinforecd beam-column joint regions were increased its maximum load carrying capacity by 1.54 times and its energy dissipation capacity by 2.36 times in comparison with standard specimen LBCJ for a displacement ductility of 4 and 7. And Specimens LBCJ-CS, LBCJ-AF series were increased its energy dissipation capacity each by 2.04~2.34, 1.63~3.02 times in comparison with standard specimen LBCJ for a displacement ductility of 7.

• Tunnel and Underground Space
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• v.24 no.5
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• pp.335-343
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• 2014

Room-and-pillar mining method is one of the most popular underground mining method in the world. If the room-and-pillar mining method is able to be adopted in civil works, it would be highly probable to reduce underground construction costs and to expand a underground structure in use. Therefore, this study aims to analyze the design procedure of unsupported rock pillars which are indispensable to ensure the stability of a room-and-pillar underground structure. Parametric studies on their key design parameters are also carried out for 125 different kinds of design conditions. From the study, the width of a rock pillar is found to show a linear relationship with its corresponding safety factor. The safety factor of a unsupported rock pillar decreased drastically like a negative exponential function as the ratio of room width to pillar width increases in the same rock strength condition. Based on the parametric studies, a design chart to simply evaluate the geometric design parameters of a unsupported rock pillar satisfying a design safety factor is also proposed in this study.

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.256-264
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• 2011

By implementing an analysis on the liquid flame proof agent infiltration of microwave-heated wood under soaking conditions (room temperature soaking, heat soaking), its correlation with wood temperature, and the structure of wood and permeating components after soaking in flame proof agent, which was carried out as basic research in order to improve the fire resistance performance of the wood itself, it is found that the infiltration increases as the microwave heating time increases, while for heat soaking, it is found that high infiltration as well as the stable permeability of flame proof agent is achievable. Also, when the wood temperature is more than $80^{\circ}C$, the infiltration by the flame proof agent increased, and a very even infiltration of flame proof agent was observed, which implies that the liquid flame proof agent has a dependency on temperature change of the wood as a condition to penetrate into the wood. As a result of fine structure analysis, the flame proof agent transfer between cells through pits was considered as a cause to increase the infiltration of flame proof agent, and it is also shown that for heat soaking among the permeating component analysis, as the crystallized flame proof agent around the heartwood and sapwood inner pits increases, the flame proof agent can penetrate into the the heartwood part.

• Journal of Korean Society of Forest Science
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• v.77 no.1
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• pp.1-9
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• 1988

To analyze phytosociological characteristics of the Mt. Namsan nature park, Seoul, vegetation structure of north-east and south-west slopes, competition capability among species, vegetation structures of afforested species were studied with belt-transect and quadrat methods. And management plan of each vegetational zone was proposed by the results of this study and the other previous reports. Numbers of species and individuals of south-west slope were greater than those of north-east slope. But species diversity of northeast showed stability of 1.0, while that of south-west showed instability from 0.8 to 1.3. The floristic dissimilarity coefficient between two slopes showed 70-80% in which species composition between two slopes was much different. Quercus mongolica was a dominant species at north-east slope and Pinus densiflora at south-west slope. Competition capability among major species was resulted in deciduous trees>Robinia pseudoacacia>Populus alba ${\times}$ glandulosa>Pinais densiflora, Quercus mongolica>deciduous trees>Pinus densiflora. Afforested vegetation at the Mt. Namsan, especially Pinus koraiensis, Abies holophylla, Picea abies, etc showed poor growth rate. The goal of the Nam-san nature park management is to conserve natural ecosystem as it is and, if necessary, to accerlerate restoration of the disturbed ecosytem to its nature by minimum energy input as possible. Management proposal was made for six vegetational management zone ; P. derasitZoru forest zone, Q. mongolica forest zone, deciduous forest zone, afforestation zone, R. pseduoacacia zone and landscape planting zone.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2003.11a
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• pp.51-55
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• 2003

The thermal behavior of NiFe$_2$O$_4$ prepared by a solid-state reaction was investigated for H$_2$ generation by the thermochemical cycle. The reduction of NiFe$_2$O$_4$ started from 800 $^{\circ}C$, and the weight loss was 0.2-0.3 wt％ up to 1000 $^{\circ}C$. At this reaction, NiFe$_2$O$_4$ was reduced by release of oxygen bonded with the Fe$^3$ion in the B site of NiFe$_2$O$_4$. In the $H_2O$ decomposition reaction, H$_2$ was generated by oxidation of reduced NiFe$_2$O$_4$. The crystal structure of NiFe$_2$O$_4$ for redox reaction maintained spinel structure. Then, NiFe$_2$O$_4$ is excellent material in the thermochemical cyclic reaction due to release oxygen at low temperature for the reduction reaction and produce H$_2$ maintaining crystal structure for redox reaction.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.9
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• pp.514-526
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• 2004

Microarray is a new technique for gene expression experiment, which has gained biologist's attention for recent years. This technology enables us to obtain hundreds and thousands of expression of gene or genotype at once using microarray Since it requires manual work to analyze patterns of gene expression, we want to develop an effective and automated tools to analyze microarray image. However it is difficult to analyze DNA chip images automatically due to several problems such as the variation of spot position, the irregularity of spot shape and size, and sample contamination. Especially, one of the most difficult problems in microarray analysis is the block and spot addressing, which is performed by manual or semi automated work in all the commercial tools. In this paper we propose a new algorithm to address the position of spot and block using a new concept of regular structure grid searching. In our algorithm, first we construct maximal I-regular sequences from the set of input points. Secondly we calculate the rotational angle and unit distance. Finally, we construct I-regularity graph by allowing pseudo points and then we compute the spot/block address using this graph. Experiment results showed that our algorithm is highly robust and reliable. Supplement information is available on http://jade.cs.pusan.ac.kr/~autogrid.