• Proceedings of the Plant Resources Society of Korea Conference
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• 2002.11a
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• pp.29-30
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• 2002

The goal of this research was to develop the effectiveness of in vitro culture method for A. formosanus and study the environment in vitro conditions affecting on growth. The first series of experiments were examined to investigate the response of three different basal media, MS (Murashige and Skoog, 1962), Knudson (KC; Knudson, 1946) and modified hyponex on growth and multiplication during in vitro culture. Multiple shoot proliferation was induced in shoot tip explants on Hyponex (H3) media supplemented with BA (1 mg1$\^$-1/) or TDZ (1-2 mg1$\^$-1/). Addition of activated charcoal (1%) to the TDZ containing medium promoted rapid shoot tip proliferation (11.1 shoots per explant) but the same medium had an opposite effect resulting in poor proliferation in the nodal explants. However, the regenerated shoots had slow growth rate and failed to elongate. This problem was overcome by transferring the shoot clumps to a hormone free H3 media supplemented with 2% sucrose and 0.5% activated charcoal. Using bioreactor culture for scaling up was also shown the best way for multiple shoot induction and growth of this plant. The second series of experiments was studied to investigate the effect of physical environment factors on growth of in vitro plantlets. The Anoectochilus formosanus plantlets were cultured under different air exchange rate (0.1, 0.9, 1.2h$\^$-1/), without sucrose or supplement 20g.1$\^$-1/ (photoautotrophic or photomixotrophic, respectively), and different photosynthesis photon flux (40, 80, 120 ,${\mu}$mol.m$^2$.s$\^$-1/- PPF). Under non-enrichment CO$_2$ treatment, slow growth was observed in photoautotrophical condition as compared with photomixotrophical condition on shoot height, fresh weigh and dry weight parameters; High air exchange (1.2.h-l) was found to be inadequate for plant growth in photomixotrophical condition. On the contrary, under CO$_2$, enrichment treatment, the plant growth parameters were sharply (visibly) improved on photoautotrophic treatments, especially on the treatment with air exchange rate of 0.9.h-1. The growth of plant in photoautotrophic condition was not inferior compared with photomixotrophic, and the best growth of plantlet was observed in treatment with low air exchange rate (0.9.h-1). Raising the PPF level from 80 to 120${\mu}$mol.m$\^$-2/.s$\^$-1/ decreased the plant height, particularly at 120${\mu}$mol.m$\^$-2/.s$\^$-1/ in photoautotrophic condition, fresh weight and dry weight declined noticeably. At the PPF of 120${\mu}$mol.m$\^$-2/,s$\^$-1/, chlorophyll contents lowed compared to those grown under low PPF but time courses of net photosynthesis rate was decreased noticeably. Light quality mainly affected morphological variables, changes of light quality also positively affected biomass production via changes in leaf area, stem elongation, chlorophyll content. Plant biomass was reduced when A. formosanus were grown under red LEDs in the absence of blue wavelengths compare to plants grown under supplemental blue light or under fluorescent light. Stem elongation was observed under red and blue light in the present experiment. Smaller leaf area has found under blue light than with other lighting treatments. Chlorophyll degradation was more pronounced in red and blue light compared with white light or red plus blue light which consequent affected the photosynthetic capacity of the plant. The third series of experiment were studied to investigate the effect of physical environment factors on growth of ex vitro plants including photosynthesis photon flux (PPF), light quality, growing substrates, electrical conductivity (EC) and humidity conditions. In the present experiments, response of plant on PPF and light quality was similar in vitro plants under photosynthesis photon flux 40${\mu}$mol.m,$\^$-2/.s$\^$-1/ and white light or blue plus red lights were the best growth. Substrates testing results were indicated cocopeat or peat moss were good substrates for A. formosanus growth under the greenhouse conditions. In case of A. formosanus plants, EC is generally maintained in the range 0.7 to 1.5 dS.m-1 was shown best results in growth of this plant. Keeping high humidity over 70% under low radiation enhanced growth rate and mass production.

• Korean Business Review
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• v.13
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• pp.133-157
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• 2000

This paper investigate to construct a new strategic trading model which contains the broker and overconfident informed trader. Assuming more favorable situation for the broker, this paper construct a two period model. At period I overconfident informed trader and liquidity traders participate to trade. At this time the broker does not execute transaction of his own account. he only transfer customer's order by commission. At period 2, the broker identifies informed trade of previous period and he execute the trade of his own account with liquidity traders. The effects of overconfidence to the expected transaction volume and expected transaction profit, and price variability are summarized as follows: (i) As the degree of overconfidence increases, the expected transaction volume of informed trader increases. Under the restriction of moderate degree of overconfidence, it also increases the expected transaction volume of broker. In sum, overconfidence behavior of informed trader increases the expected transaction volume. (ii) As the degree of overconfidence increases, the both expected profit of informed trader and broker decrease. (iii) As the degree of overconfidence increases, unconditional variances of price for each periods increase. And as the degree of overconfidence increases, the informativeness of prices for each period increase. Finally, some limitations of this paper and direction for further research were suggested.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.1-20
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• 1997

Skeletal Class III malocclusions are growth-related discrepancies, and the problems are more severe until growth is complete. Causes of skeletal Class III malocclusion are classified into mandibular overgrowth, maxillary deficiency, and combination of the two. Face mask has been recommended for treatment of Class III malocclusion with maxillary deficiency in the early time of growth. Numerous experiments were performed and clinical studies have been reported on face mask ; nevertheless, studies on profile changes and stability after treatment of face mask are considered to be somewhat insufficient. The author selected 50 patients who can be checked for follow-up. They had been diagnosed as skeletal Class III malocclusion with maxillary deficiency and then treated with face mask ; the sample group was divided according to sex, treatment beginning age, palatal suture opening (intraoral appliance). For each group, changing pattern of facial profile and stability of treatment observed, and comparison with 20 Korean normal children(Angle's Class I). The following results were obtained. 1. skeletal, dental, and soft tissue measurements indicated more changes in the amounts of maxillary forward movement during face mask treatment. 2. R.P.E. group showed more significant maxillofacial changes and La-Li group showed more dental changes. 3. Growth changes of maxilla induced in the treatment group during wearing face mask were much more than those of normal group. 4. Growth changes of maxilla in the treatment group after treatment of face mask were less than those of normal group. From the obtained aata, it can be concluded that there was a stimulative effect on forward growth of maxilla during the use of face mask ; however, on removal of face mask, the stimulative effect was eliminated and undergrowth tendency of maxilla resumed.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.141-155
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• 1997

The purpose of this study was to evaluate the effectiveness of the Nd:YAG laser and the Er:YAAG laser on etching enamel for direct bonding of orthodontic bracket. The advantages of laser etching rather than conventional acid etching are to reduce the subsurface demineralization rate, to inhibit the spillage of acid onto uninvolved ""its of enamel, and to save the clinical manipulation time involving drying, trashing and drying again. 189 freshly extracted human premolars were prepared for this research. 165 out of them were divided into 11 groups of 15 teeth. One group was acid etching and the rest groups were irradiated with Nd:YAG laser by four different energy levels(100mj 10pps, 100mj 20pps, 150mj 20pps, 200mj 20pps) and with Er:YAG laser by six different energy levels(60mj 5pps, 60mj 10pps, 100mj 10pps. 200mj 10pps, 200mj l5pps, 400mj 10pps). Shear bond strength was tested with Instron after 24 hours, one week, and three weeks. Twenty-four out of 189 teeth were divided into twelve groups untreated control, acid etching, and ten laser irradiation subgroups. And the ultrastructural enamel surfaces of each group were observed with scanning electron microscope. The results were as follows; 1. The means and the standard deviations of shear bond strength of Nd:YAG and Er:YAU laser irradiation by different energy levels were obtained. 2. Shear bond strengths of Er:YAG laser irradiation groups were higher than those of Nd:YAG laser irradiation groups at the identical energy level. 3. Maximum bond strengths was achieved at the energy of I50mj, 20pps in Nd:YAG laser irradiation groups or 60mj, 10pps in Er:YAG laser irradiation groups. 4. It was acceptible for direct bonding to irradiate lb0mj 20pps with Nd:YAG laser or to irradiate 60mj 10pps with Er:YAG laser considering the results of shear bond strength tests and SEM obsesvation.

• Journal of Oral Medicine and Pain
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• v.31 no.3
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• pp.223-229
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• 2006

The objectives of this study was to investigate the amount of tooth ablation and the change of intrapulpal temperature by Er:YAG laser as it relates to pulse energy and pulse repetition rate at the identical power and, thereby, to reveal which of the two parameters strongly relates with ablation efficiency and intrapulpal temperature. Extracted healthy human molar teeth were sectioned into two pieces and each specimen was irradiated within the combination of pulse energy and pulse repetition time at the same power of 3W; $300mJy{\times}10Hz$ group, $200mJy{\times}15Hz$ group, and $150mJy{\times}20Hz$ group. Each specimen comprised ten tooth specimens. A laser beam with conjunction of a water flow rate of 1.6 ml/min was applied over enamel surfaces of the specimens during 3 seconds and the ablation amount was determined by difference in weight before and after irradiation. To investigate the temperature change in the pulp according to the above groups, another five extracted healthy human molar teeth were prepared. Each tooth was embedded into resin block and the temperature-measuring probes were kept on the irradiated and the opposite walls in the dental pulp during lasing. When the power was kept constant at 3W, ablation amount increased with pulse energy rather than pulse repetition rate (p=0.000). Although intrapulpal temperature increased with pulse repetition rate, there were no significant differences among the groups and between the irradiated and the opposite pulpal walls, except at a condition of $150y{\times}20Hz$ (p=0.033). Conclusively, it is suggested that ablation efficacy is influenced by pulse energy rather than pulse repetition rate.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.319-324
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• 2014

The aim of this study was to evaluate influences of titanium dioxide ($TiO_2$) concentrations and irradiation times on growth of Streptococcus mutans when irradiated by visible light (405 nm wavelength) and by ultraviolet light (254 nm wavelength). To find the optimal antibacterial concentration of $TiO_2$, 0.01, 0.1, 1.0, and 10.0 mg/ml $TiO_2$ suspension was prepared with sterilized distilled water. S. mutans cultured media was added to $TiO_2$ solution to set the final cell count to $10^4CFU/ml$. The photocatalytic reaction was induced by irradiating 254 nm and 405 nm lights for 10 minutes. To compare the bactericidal activities according to irradiation times, all photocatalytic reaction was carried out with 0.1 mg/ml $TiO_2$ for 0, 10, 20, 30, and 40 minutes with both lights. After the photocatalytic reaction, $100{\mu}m$ of the reaction mixture was immediately plated on brain heart infusion agar. These plates were placed at 5% $CO_2$, $37^{\circ}C$, for 24 hours and the bacterial colonies were counted. All experiments were performed in quintuplicate. One-way ANOVA was used to determine whether there were any significant differences between the $TiO_2$ concentrations or the irradiation times. The most effective concentration of $TiO_2$ for its photocatalytic bactericidal effect on S. mutans was 0.1 mg/ml when irradiated with 254 nm and 405 nm lights. The longer the irradiation time, the bigger the bactericidal effect for both wavelengths. Over 99% of bacteria in the inoculum were killed after irradiation with 254 nm for 20 minutes and with 405 nm for 40 minutes. In conclusion, a photocatalytic reaction of $TiO_2$ induced by visible light of 405 nm constitutes the bactericidal effect on S. mutans.

• Korean Journal of Environment and Ecology
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• v.25 no.5
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• pp.767-786
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• 2011

This study analyzed and compared characteristic of vegetation structure in Bonghwa mountain, the base Mt. outside urban area, and Hakseoung neighborhood park, Ilsan neighborhood park and Musil neighborhood park, disconnected residual Mt. inside urban area of Wonju. Regarding vegetation of urban forest in Wonju, Quercus mongolica forest and Robinia pseudo-acacia forest were widely distributed in the base Mt. outside urban area. Quercus acutissima forest and Robinia pseudo-acacia forest were widely distributed in the disconnected residual Mt. inside urban area. Forests in both areas were managed as part of forest management campaign. Analysis on importance value of a community classified by DCA and DBH class categorized communities into three groups according to the expected ecological succession. Community B was the one to be maintained as Pinus densiflora community. Community A, D and d were expected to be maintained as Quercus spp. Community. Community C, E, F, e, f and g were classified as exotic plant community. Ecological succession was suspended in both base Mt. outside urban area and disconnected residual Mt. inside urban area. However, importance value of Quercus spp. which appeared in the understory layer and shrub layer and their DBH class showed that the potential for ecological succession of exotic plant community was higher in base Mt. outside urban area than disconnected residual Mt. inside urban area. According to the analysis on number of species and individuals and species diversity, understory and shrub layer were reduced due to Forest Management campaign and plant species which appear at an earlier stage of succession varied as time went by since the campaign began. Species diversity comparison between natural and artificial forest showed no clear difference in both base Mt. outside urban area and disconnected residual Mt. inside urban area due to man-made disruption such as thinning and brush cutting. Six communities in base Mt. outside urban area had 17.76~52.22% of similarity index. Four communities in disconnected residual Mt. inside urban area showed 13.34~37.01% of similarity index, which was lower than base Mt. outside urban area. Among naturalized plants, Tupatorium rugosum and Phytolacca americana appeared more in disconnected residual Mt. inside urban area.

• Journal of agricultural medicine and community health
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• v.28 no.1
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• pp.15-27
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• 2003

Objectives: This study was conducted to compare the medical care patterns of hypertensive patients between rural and urban areas. Methods: We selected one rural county(Region A where there were 19 public health centers; one health center, 8 health sub-centers and 10 community health posts) and two urban districts(Region B and C where there was no health sub-center and community health post) in Daegu city. Region B had similar socioeconomic characteristics with rural county A while region C had different characteristics. The medical insurance records of 14,422 incident patients (2,501 in region A, 4,873 in region B and 7,048 in region C) with diagnostic code of hypertension from September 1998 to August 1999 were reviewed. Incident patient was defined as a patient who had no record of medical fee claim for hypertension to the national health insurance corporation in past 6 months and visited a medical facility for hypertension for the first time. The data for annual visit days, annual prescription days and annual total medical expenses were abstracted. The medical care pattern was categorized by the number of annual visit days and prescription days. The most proper care group was defined as the patient who visited 6-15 days with 240 prescription days or more in a year. Results: The type of medical facilities for the most visit was clinics, 373.% and it was followed by general hospitals, 28.2%; public health centers, 24.7%; and hospitals, 9.8% in region A(p<0.05). In region B, it was clinics, 63.1% and followed by general hospitals, 27.6%; health center, 5.2%; and hospitals, 4.1%(p<0.05). In region C, it was clinics, 53.8% and followed by general hospitals, 35.0%; health center, 6.3%; and hospitals, 4.9%(p<0.05). Annual mean total medical expenses per patient was highest in region C(won195,993) and followed by region A(won191,683) and region B(won178,713). The proportion of the most proper care group was 7.7% in region A, 5.2% in region B and 6.7% in region C(p<0.05). According to the type of medical facilities for the first visit, the proportion of the most proper care group was highest(14.7%) in the patients of public health centers, and it was followed by general hospitals, 8.8%; clinics, 3.6%; and hospitals, 2.0% in region A(p<0.05). In region B, it was highest in general hospitals, 9.7% and followed by hospitals, 4.0%; health center, 3.6%; and clinics, 3.4%(p<0.05). In region C, it was highest in general hospitals, 10.1% and followed by clinics, 5.2%; hospitals, 4.1%; and health center, 3.1%(p<0.05). Conclusions: The proportion of proper care for hypertension was higher in rural area and it was attributed to the care of health center, sub-centers and community health posts which appeared to follow patients better than hospitals and clinics.

• Journal of agricultural medicine and community health
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• v.29 no.2
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• pp.287-301
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• 2004

Objectives: The development of internet programs for smoking cessation was motivated to quit smoking in the large group of smokers. This personalized program consisted of tailored message to consider the smokers characteristics, and contain the informations on the outcomes of smoking cessation and the skills to be used in the quit attempts. The purpose of this study was to develop the internet management program and information push-delivery system for smoking cessation to encourage the personal intention to quit smoking. Methods: We conducted in 3 steps as developing push service to encourage intention of smoking cessation, analyzing problems of smoking cessation program through the pilot test and suggesting improvements by implication stages. Results: This program is delivered for 30 days. if the participants do not fail to quit smoking. The contents consisted of 13 stages which were divided on starting period. practical period, maintenance period and success period. And push service afforded the tailored message to participants using their e-mail. According to the evaluation of pilot test, the problems of internet information push-delivery service for smoking cessation were the over-tasks per visiting time, recording style of participants, difficulty of terms and sentences, lack of visual effects, absence of follow-up module and unsuitable link with main homepage. Improvements were divided on 3 stages by implication period. The first stage included the immediate improvements as improving link with homepage, modifying menu of smoking information and upload file of notice part. The second stage included the short term improvements as alleviating condition of withdrawal, coordinating start stage of retrial, modifying errors of information push-delivery service and addition of educational materials. The third stage included the long term improvements as development of follow-up module, cost-effectiveness evaluation, reducing contents quantity, introduction of checking style, compensation of graphics effect and review for SMS utilization. Conclusions: This program contribute to improving smoking cessation rate. Therefore this program should be tested in a community to evaluate the effectiveness. To promote the effectiveness, this program should be developed the contents and the strategies for various targets, and established the follow-up system for ex-smokers.

• Korean journal of communication and information
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• v.22
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• pp.131-166
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• 2003

The opening of advertising market and introduction of the free competition doctrine make the competition harsher among advertising agencies. Advertising agencies do their best to execute their ad more efficiently and scientifically. But, it is the reality that broadcasting advertising industry in korea did not construct enough infrastructure to execute the systematic activities compared with that of advanced countries. So, we need to grasp the present conditions and draw a time-table to construct primarily necessary infrastructures. In case of hardware infrastructure in advertising industry, digitalization of broadcasting and convergence of broadcasting with telecommunication make it hurry to construct that. But as the ad agencies was in the situation to compete each other, they have a difficulty to construct common hardware infrastructure enthusiastically. Thus, it is necessary to build hardware infrastructure in advertising industry for policy. And the construction of that should be executed systematically not for the short term effects but for the long term objectives. Also, it is the most important to construct reliable Software infrastructure in advertising industry from all of ad agencies. In these days, ad agencies have a tendency not to believe the important information, like the data of ratings and advertising transaction information, in relation to the advertising activities. And they do not share and communicate about the information of the advertising industry trends, research trends, advertisement related information. So, it is also hurry to build the on-line and off-line database system. Finally, for the development of brainware infrastructure in advertising industry, it is the most necessary to activate the cooperation relation between university and advertising agencies. Universities need to invite experts in the advertising to teach the students practical knowledge and ad agencies to recruit students who want to develop their carrier in the advertising industries. In conclusion, advertising industry in korea to solve these tasks for the development of advertising industry infrastructure in the way of cooperation and harmony of each other rationally and efficiently.