• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.167-174
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• 2015

Purpose : The pre-treatment QA using Portal dosimetry for Volumetric Arc Therapy To analyze whether maintaining the reproducibility depending on various factors. Materials and Methods : Test was used for TrueBeam STx$^{TM}$ (Ver.1.5, Varian, USA). Varian Eclipse Treatment planning system(TPS) was used for planning with total of seven patients include head and neck cancer, lung cancer, prostate cancer, and cervical cancer was established for a Portal dosimetry QA plan. In order to measure these plans, Portal Dosimetry application (Ver.10) (Varian) and Portal Vision aS1000 Imager was used. Each Points of QA was determined by dividing, before and after morning treatment, and the after afternoon treatment ended (after 4 hours). Calibration of EPID(Dark field correction, Flood field correction, Dose normalization) was implemented before Every QA measure points. MLC initialize was implemented after each QA points and QA was retried. Also before QA measurements, Beam Ouput at the each of QA points was measured using the Water Phantom and Ionization chamber(IBA dosimetry, Germany). Results : The mean values of the Gamma pass rate(GPR, 3%, 3mm) for every patients between morning, afternoon and evening was 97.3%, 96.1%, 95.4% and the patient's showing maximum difference was 95.7%, 94.2% 93.7%. The mean value of GPR before and after EPID calibration were 95.94%, 96.01%. The mean value of Beam Output were 100.45%, 100.46%, 100.59% at each QA points. The mean value of GPR before and after MLC initialization were 95.83%, 96.40%. Conclusion : Maintain the reproducibility of the Portal Dosimetry as a VMAT QA tool required management of the various factors that can affect the dosimetry.

• Journal of Plant Biology
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• v.38 no.3
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• pp.305-317
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• 1995

The bryophyte communities on the forest floor of the mixed coniferous, deciduous broad-leaf forest and the evergreen coniferous forest of cool temperate and subalpine zones in Chiri Mountains with the highest peak (Cheonwangbong 1915 m) in south-central part of the Korean Peninsula were investigated from the phytosociology viewpoint. As a result, five bryophyte communities were recognized, considering the species composition of vascular vegetation; A. Sasamorpha borealis-Abies koreana/Dicranum scoparium-Plagiothecium silvaticum community, B. Bosta minor-Abies koreana/Anomodon rugelii-Plagiomnium cuspidatum community, C. Abies koreana/Hylocomiopsis ovicarpa-Entodon rubicundus community, D. Abies koreana-Picea jezoensis/Hylocomiopsis ovicarpa-Thuidium kanedae community, E. Abies koreana-Pieea jezoensis/Hylocomium splendens-Pleurozium sehreberi community. Among these, the communities A, B, C and D were distributed in the mixed coniferous and deciduous broad-leaf forest of lower altitudes (1200 to 1700 m) and characterized by the elements of the cool temperate zone. They were confimled as synusies belonging to the Fraxino-Abietetum koreanae Song 1988. The community E was distributed in higher altitudes (1700 m to near the summit) and characterized by the species group of the holarctic elements, e.g. Hyloeomium splendens, Pleurozium sehreberi, Dieranum majus, etc. limited in subarctic; subalpine and arctic; alpine zones. The community E was confirmed as a synusie of the Abieti koreanae-Piceetum jezoensis Song 1991 belonging the Vaecinio-Pieeetea Br.-BI. 1939. Up to date many investigator have described the coniferous forest distibuted above 1200 m in Chiri mountauns as the forest vegetation of subalpine zone. However, from the results of the present study, the boundary of the mixed forest and the true subalpine coniferous forest was elucidated to be ca. 1700 m phytosociologically. Species richness was highest in the community E, and the other four communities showed a similar species richness. Among the species diversity indices, H' and D were high in the communities Band E, low in the communities A and C, and medium in the community D. The values of J' decreased with the increase in altitudes and the community E showed the lowest value. The result of Bray-Curtis ordination revealed that the diversity analysis and the division of the above two forest zones are justifiable. The taxa of the bryophyte communities were composed of 25 families, 46 genera, 73 species, 1 subspecies and 2 varieties.

• Journal of the Korean Society of Radiology
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• v.14 no.2
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• pp.105-109
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• 2020

Intensity-modulated radiotherapy(IMRT) has disadvantages such as increasing the low doses of irradiation to normal tissues and accumulated dose for the whole volume by leakage and transmission of the Multi Leaf Collimator (MLC). The accumulated dose and low dose may increase the occurrence of secondary malignant neoplasms. For this reasons, the jaw tracking function of the TrueBeam (Varian Medical Systems, Palo Alto, CA) was developed to reduce the leakage and transmission dose of the MLC with existing linear accelerators. But quantitative analysis of the dose reduction has not been verified. Therefore, in the present study, we intended to verify the clinical possibility of utilizing the jaw tracking function in brain tumor with comparison of treatment plans. To accomplish this, 3 types of original treatment plans were made using Eclipse11 (Varian Medical Systems, Palo Alto, CA): 1) beyond 2 cm distance from the Organs At Risk (OARs); 2) within 2 cm distance from the OARs; and 3) intersecting with the OARs. Jaw tracking treatment plans were also made with copies of the original treatment planning using Smart LMC Version 11.0.31 (Varian Medical Systems, Palo Alto, CA). A comparison between the 2 types of treatment planning methods was performed using the difference of the mean dose and maximum dose to the OARs in cumulative Dose Volume Histogram (DVH). In the DVH comparison, the maximum difference of 0.5 % was observed between the planning methods in the case of over 2 cm distance, and the maximum of 0.6 % was obtained for within the 2 cm distance. For the case intersecting with the OAR, the maximum difference of 2 % was achieved. According to these results, it could be realized that the differences of mean dose and maximum dose to the OARs was larger when the OARs and PTV were closer. Therefore, treatment plans with the jaw tracking function consistently affected the dose reduction and the clinical possibility could be verified.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.352-356
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• 2011

It is true that the industrial development has usually been accompanied with urbanization or centralization of population that has inevitably led to high-rise buildings and densely built-up living area in the cities. While it is badly needed to acquire as much green land within the city limits as possible to compensate for reduced space for recreational purpose in parallel with increasingly urbanized area, the living conditions of plants have become seriously devastated due to shortage of sun light walled-off by high-rise buildings and contaminated environment and air. The shade that is generated by high-rise and compact buildings hinders growth of plants, which makes it urgent to develop native ground cover plant that is strongly viable in the shade. For this purpose, Ligularia stenocephala, best known as greens for Ssam (rice and condiments wrapped in leaves) was cultivated under the 30%, 50%, and 80% shadings and observed to see if there would be any changes in soil conditions, growth of plants and chlorophyll contents depending on the shading rate. The leaf number was 10.8 pieces under the 50% shading and 8.4 under the 30%-shading, 7.7 pieces more than that cultivated under lighting. The leaf width turned out to be excellent from cultivation under the 50%- shading, an evidence indicating its possibility of being cultivated as native ground cover plant in the shade. The live weight of the plants cultivated under the shading increased to 31.63 g, 43.39 g and 19.40 g, respectively, compared to 90.43 g of those in the untreated control plot. The increase in growth of roots was particularly significant with 48.48 g in comparison to 12.33 g under 30% shading cultivation. The chlorophyll synthesis amounted to 46.2 under the 50% shading, showing an increase compared to 41.9 under lighting. The chlorophyll synthesis rather shrank under other shading conditions. The cultivation of Ligularia stenocephala under the 50% shading showed the best condition in growth as native ground cover plant.

• Korean Journal of Environmental Agriculture
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• v.38 no.4
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• pp.225-236
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• 2019

BACKGROUND: Hydroponics is one of the methods for evaluating plant production using the inorganic nutrient solutions, which is applied under the artificial light conditions of plant factory system. However, the application of the conventional inorganic nutrients for hydroponics caused several environmental problems: waste from culture mediums and high nitrate concentration in plants. Organic nutrients are generally irrigated as a supplementary fertilizer for plant growth promotion under field or greenhouse conditions. Hydroponic culture using organic nutrients derived from the agricultural by-products such as dumped stems, leaves or immature fruits is rarely considered in plant factory system. Effect of organic or conventional inorganic nutrient solutions on the growth and nutrient absorption pattern of green and red leaf lettuces was investigated in this experiment under fluorescent lamps (FL) and mixture Light-Emitting Diodes (LEDs). METHODS AND RESULTS: Single solution of tomatoes (TJ) and kales (K) deriving from agricultural by-products including leaves or stems and its mixed solution (mixture ration 1:1) with conventional inorganic Yamazaki (Y) were supplied for hydroponics under the plant factory system. The Yamazaki solution was considered as a control. 'Jeockchima' and 'Cheongchima' lettuce seedlings (Lactuca sativa L.) were used as plant materials. The seedlings which developed 2~3 true leaves were grown under the light qualities of FL and mixed LED lights of blue plus red plus white of 1:2:1 mixture in energy ratio for 35 days. Light intensity of the light sources was controlled at 180 μmol/㎡/s on the culture bed. The single and mixture nutrient solutions of organic and/or inorganic components which controlled at 1.5 dS/m EC and 5.8 pH were regularly irrigated by the deep flow technique (DFT) system on the culture gutters. Number of unfolded leaves of the seedlings grown under the single or mixed nutrient solutions were significantly increased compared to the conventional Y treatment. Leaf extension of 'Jeockchima' under the mixture LED radiation condition was not affected by Y and YK or YTJ mixture treatments. SPAD value in 'Jeockchima' leaves exposed by FL under the YK mixture medium was approximately 45 % higher than under conventional Y treatment. Otherwise, the maximum SPAD value in the leaves of 'Cheongchima' seedlings was shown in YK treatment under the mixture LED lights. NO₃-N contents in Y treatment treated with inorganic nutrient at the end of the experiment were up to 75% declined rather than increased over 60 % in the K and TJ organic treatment. CONCLUSION: Growth of the seedlings was affected by the mixture treatments of the organic and inorganic solutions, although similar or lower dry weight was recorded than in the inorganic treatment Y under the plant factory system. Treatment Y containing the highest NO₃-N content among the considered nutrients influenced growth increment of the seedlings comparing to the other nutrients. However effect of the higher NO₃-N content in the seedling growth was different according to the light qualities considered in the experiment as shown in leaf expansion, pigmentation or dry weight promotion under the single or mixed nutrients.

• Korean Journal of Soil Science and Fertilizer
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• v.1 no.1
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• pp.89-115
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• 1968

1. The experiment was carried out for investigating the interaction between potassium nutrition and thermoperiod (as an environment regulating factor) in relation to behaviors of several nutrients including phosphorus-32 and Potassium-42 in IPOMOEA BATAS. 2. To obtain same condition to trace the behaviors of phosphorus and potassum-42 they were simultaneously incorporated to roots. The determination of each CPM by counting twice with adequate interval and calculating true CPM of each isotope according to different half-life, was carried out with satisfactory. 3. Some specific symptoms i.e, chlorosis and withering of growing point under the condition of lower potassium level were found and was accelerated by the low night temperature. 4. A manganese shortage in growing point of the lower potassium level was found by activiation analysis and very low distribution ratio of phosphorus-32 and potassium-42 in the growing point of the lower potassium level was manifested, though the contents of nitrogen, phosphorus, potassium, sodium and magnesium were not in great difference. 5. In addition to the low water content with appearence of "hard", shorterning internode and lower ratio of roots to shoot as well as the symptoms of potassium deficiency such as brown spot in leaf blade and necrosis of leaf margin were appeared at later stage of experiment at the lower potassium level. 6. Very stimulating vegetative growth, e.g, large plant length, leaf expansion, increasing node number and fresh weight as well as high ratio of roots to shoot, high water content was resulted in the condition of higher potassium level. 7. A specific interaction between higher potassium level and thermoperiod was found, that is, the largest tuber production and the largest ratio of roots to shoot were resulted in the combined condition of higher potassium level and constant temperature while the largest plant length, fresh weight etc. i.e. the most stimulative vegetative growth was resulted in the combined condition of higher potassium level and low night temperature. 8. Comparatively low water content in the former condition of stimulative tuber production was resulted(especially at the tuber thickening stage), while high water content in the latter condition of stimulative vegetation was resulted though the higher potassium level made generally high water contents. 9. The nitrogen contents of soluble and insoluble did not make distinct difference between the lower and higher potassium level. 10. Though the phosphorus contents were not distinctly different by the potassium level, the lower potassium level made the percentage of phosphorus increased at tuber forming stage accumulating more phosphorus in roots, while the higher potassium level decreased percentage of phosphorus at that stage. 11. The higher potassium level made distinctly high potassium contents than the lower potassium level and increased contents at the tuber forming stage through both conditions. 12. The sodium contents were low in the condition of higher potassium level than the lower potassium level and decreased at tuber forming stage in both conditions, on the contary of potassium. 13. Except the noticeable deficeney of manganese in the growing point of the lower potassium level, mangense and magnesium contents in other organs did not make distinct difference according to the potassium level. 14. Generally more uptake and large absorption rate of phosphorus-32 and potassium-42 were resulted at the higher potassium level, and the most uptake, and the largest absorption rate of phosphorus and potassium-42 (especially potassium-42 at tuber forming stage) were resulted in the condition of higher potassium level and constant temperature which made the highest tuber production. 15. The higher potassium level stimulated the translocation of phoshorus-32 and potassium-42 from roots to shoots while the lower potassium level suppressed or blocked the translocation. 16. Therefore, very large distribution rate of $p^{32}$, $K^{42}$ in shoot, especially, in growing point, compared with roots was resulted in the higher potassium level. 17. The lower potassium level suppressed the translocation of phosporus-32 from roots to shoot more than that of potassium-42. 18. The uptake of potassium-42 and translocation in IPOMOEA BATATAS were more vivid than phosphorus-32. 19. A specific interaction between potassium nutrition and thermoperiod which resulted the largest tuber production etc. was discussed in relation to behaviors of minerals and potasium-42 etc. 20. Also, the specific effect of the lower and higher potassium level on the growth pattern of IPOMOEA BATATAS were discussed in relation to behaviors of minerals and isotopes. 21. An emphasize on the significance of the higher potassium level as well as the interaction with the regulating factor and problem of potassium level (gradient) for crops product ion were discussed from the point of dynamical and variable function of potassium.

• Korean Journal of Plant Taxonomy
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• v.31 no.3
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• pp.283-309
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• 2001

Acer pictum complex (A. pictum Thunb. ex Murray with varieties, A. okamotoanum Nakai, A. truncatum Bunge) in eastern Asia causes frequent difficulty in identification. One hundred twenty five specimens from A. pictum complex of China, Korea and Japan and A. cappadocicum var. sinicum of China were compared to investigate patterns of intra- and interspecific variation and to evaluate a recognition of several species as well as many varieties using 22 characters for morphometric analysis. The first three PCA accounted for 59% of the total variance. No strong discontinuities existed among taxa with respect to fruit and leaf characters. Much overlap among all taxa occurred the central region of the scatter diagram. Many characters appeared to show some clinal variation with changes from east of China to Japan through Korea. This was true not only when all species as considered as a single taxon, but when characters of individual taxa were compared with geography. As one considers a path from the western part of the ranges to areas to the east, the leaves become larger in most respects and become increasingly many lobed (five to seven or nine). In general, there was a tendency toward larger nutlet with smaller wing in the area toward northeast of China (=A. truncatum), while in the east of ranges (Island Ullung-do), plants were larger with respect to characters of fruit and leaves (=A. okamotoanum). The morphological differentiation between A. okamotoanum and Japanese and Korean individuals of A. pictum was not considered sufficient to warrant recognition of either specific or varietal status and should be treated as con specific under A. pictum var. mono. Since the lectotype of Acer pictum had minute hairs uniformly on the under surface of leaves(A. pictum var. pictum), the glabrous type of A. pictum was called A. pictum var. mono as Ohahsi suggested. The univaraite analysis (the mean and maximum/minium of nutlet size and wing/nutlet length ratio) indicated geographical differentiation of northeastern populations, A. truncatum, was distinctive, but Korean individuals of A. truncatum showed an affinity between Chinese individuals of A. truncatum and Korean individuals of A. Pictum var. mono. The current results, together with qualitative character, trunk features, justify subspecific status for this taxon. The previous varieties of A. mono in Korea were indistinguishable from typical form of A. Pictum var. mono on the basis of the wing angle and nutlet size, rejecting continued recognition of these taxa as distinctive varieties. Therefore, it is recommended that only one polymorphic species of A. pictum be recognized in addition to three varieties.

• Journal of the Korean Institute of Landscape Architecture
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• v.38 no.2
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• pp.94-108
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• 2010

The purpose of this study is to provide data for the restoration of 'Yongyun(龍淵)' and 'Hwahongmun(華虹門)' through an investigation of the vicinity of their original landscapes at the time of construction of Hwaseong in Suwon and through tracing the transformative process of the environments of this vicinity. The results are as follows; As identified by 'Yongyunjung(龍淵亭)' and 'Yongdugak(龍頭閣)', other names of Yongyun, 'Banghwasuryujung(訪花隨柳亭)', which was built on 'Yongduam', is a facility whose place identity is highlighted with a sense of unity with Yongyun. The south lakefront of Yongyun, bordering Banghwasuryujung, has boundaries that make the best use of the natural geographical features of Yongduam while the current circumference of Yongyun is comparatively shorter than its original state. The size of 'Joongdo(中島)', however, seems to be an example of apparent over-design complement and reorganize 'Joongdo', which had been restored larger than its original state at the time of restoration in the 1970s. The depth of 'Yongyun' was created to be lower than the actual depth, without consideration for its initial depth, as soil was accumulated through continuous flooding after it was created. It is assumed that the original drains which were installed about 10m inside the lake were created facing the stream. As regards the planting environment, a circular planting of willows was made in the outskirts of 'Yongyun', except the 'Yongduam' which is a pure forest, and a mix of 'Pinus densiflora', shrubbery and deciduous broad leaf trees was planted in 'Joongdo'. Of the plants growing in the area of this study, plant species introduced to Korea after Hwaseong was constructed are found, most of which provide interest and attraction. The old pine trees growing in a group once grew in the castle areas of the vicinity even in the 1920s, the period of Japanese occupation, but they disappeared from the area in the aftermath of subsequent urban development and the Korean War. Although restored to the site, the number and space taken up by these trees are insignificant compared to those of the original environment. On the basis of these results, the following is considered necessary for the true restoration of the vicinity of 'Yongyun' and 'Hwahongmun': First, the grounds of 'Yongyun' should be dredged deeply enough to expose the bedrock and should be recreated in the rough outline of a half moon by extension to the southwest toward 'Yongduam' and 'Hwahongmun', and the size of 'Joongdo' should be significantly reduced. Secondly, considering that most plant species, except the pine trees and wild trees in 'Yongduam', are non-native plants introduced in order to provide such attractions such as the appreciation of scenic areas, they should be replaced with native species, mainly with the pine trees which were utilized during the construction of Hwaseong. The weeping willows planted in the 'middle-island' should be relocated to the outskirts of 'Yongyun', and replaced with pine trees as the major trees and maple trees or deciduous broadleaf trees to fill in the gaps. Thirdly, exotic species such as the 'Pinus rigida' planted in a group around 'Banghwasuryujung' and 'Bugammun' and 'Pinus strobus' planted in the vicinity of Hwahongmun' should be removed.

• Journal of Bio-Environment Control
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• v.25 no.1
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• pp.42-48
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• 2016

Angelica gigas, belonging family Apiaceae, is a perennial and famous medical plant growing in Korea, Japan, and China. The aims of this study was to analyze the growth and accumulated Decursin and its precursor Decursinol angelate of A.gigas grown under fluorescent lamp and LED. A. gigas 'Manchu' were sowed and managed for seedlings stage in a glass house for 4 weeks. One hundred twenty seedlings with 3 true leafs were transplanted at an ebb & flow system with fluorescent lamp and LED [red: peak wavelength 660nm, blue: peak wavelength 455 nm, white = 3:2:4 ratio] irradiated at $180{\pm}7{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ at the top of plant canopy for 5 weeks. The number of leaves increased by 13.5% in the LED treatment, though it is not statistically significant. Leaf length/width ratio of A. gigas grown under the fluorescent lamps was 24% bigger than the LED treatment and also the stem was 13% larger. Maximum root length was similar to both groups. Fresh weight and dry weight of shoots grown under the LED increased by 50% and 42% and the both weights of roots increased by 125% and 45%, respectively. The contents of Decursin and Decursinol angelate grown under the florescent lamps were larger than LED by 188% and 27% in shoot and 78% and 8% in root. The contents of Decursin and Decursinol angelate per plant grown under LED and florescent lamps were 132mg and 122mg. In conclusion, functional materials in A. gigas were increased by florescent light and its growth was promoted by LEDs light.

• Horticultural Science & Technology
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• v.30 no.5
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• pp.484-492
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• 2012

The present study aimed to investigate the effect of static magnetic field (SMF) on the growth and physiological characteristics of common indoor plant species. Five foliage plant species, Spathiphyllum spp., Ardisia pusilla DC., Syngonium podophyllum, Peperomia pereskiifolia, and Pilea cadierei were potted into plastic pot equipped with round type anisotropic sintered NdFeB permanent magnet inside the pot. The surface magnetic flux density of each magnet was 3,500 G. After 6 months of growth period, the biomass accumulations of Spathiphyllum, A. pusilla, and P. cadierei under SMF were statistically higher than those of controls. Tissue water content also increased under the influence of SMF in most species. The photosynthetic rate of Spathiphyllum under SMF significantly increased but other species showed no significant difference compared with control. Although there was no significant increase in the photosynthetic rates of A. pusilla, and P. cadierei, they showed remarkable increase in total fresh weight under SMF. This suggests that the demand of assimilates for normal metabolism could be decreased under magnetic influence and thereby biomass accumulation could be more favored. But this is not always true for all plant species because P. pereskiifolia in this experiment, showed no changes in both photosynthetic rate and biomass accumulation. Leaf nitrogen and chlorophyll contents were enhanced significantly in most plant species under influence of SMF. Chlorophyll a/b ratio also increased by SMF. Although there might be a limitation depending on plant species, these results suggest that long-term exposure to SMF might allow plant to have an enhanced acclimation capacity against environmental fluctuations and optimal application of SMF could increase the practical use of indoor plants such as an attempt to improve indoor air quality.