• The Journal of the Acoustical Society of Korea
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• v.41 no.5
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• pp.481-491
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• 2022

The active sonar transmission system consists of a transmitter that outputs an electrical signal and an underwater acoustic transducer that converts the amplified electrical signal into an acoustic signal. In general, the transmitter output characteristics are dependent on load impedance, and an underwater acoustic transducer, which is a transmitter load, has a characteristic that the electrical impedance varies largely according to frequency when driven. In such a variable impedance condition, the output of the active sonar transmission system may become unstable. Hence, this paper proposes a design and control technique of a sonar transmitter for transmitting a stable transmission signal even under variable impedance conditions of an underwater acoustic transducer in an active sonar transmission system. The electrical impedance characteristics of the underwater acoustic transducer are experimentally analyzed, and the sonar transmitter is composed of a single-phase full-bridge inverter, an LC filter, and a matching circuit. In this paper, the design and output control method of the sonar transmitter is proposed to protect the transmitter and transducer. It can secure stable output voltage characteristics even if it transmits the Linear Frequency Modulation (LFM) signal. The validity is verified through the simulation and the experiment.

• Journal of the Korean Society of Floral Art and Design
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• no.42
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• pp.145-156
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• 2020

The purpose of this study was to investigate status survey on flower products with high sales by item and peak season. The survey was implemented for 103 people who are running flower shop and are members of association for Engineer Floral Design who are acquired Craftsman Floral Design and Engineer Floral Design. The result of this study, the peak season for the sale of flower product is showed May (52.0%) and February (24.3%). The reason for the selection was in May, month of family, teacher's day, etc. in February, personnel transfer and graduation ceremony. As a result of researching flower products with high sales volume by category, Cut flowers were ranked the first place of bouquet (51.5%%, 40.3%) and the second place of basket (28.8%, 37.5%) on annual and peak season. And also, Corsage, which was 6^th (1.8%) in the annual sales volume survey, increased to 3^rd (8.0%) during peak season. Pot plants were ranked 1st of foliage plant (50.6%, 51.3%) and 2nd tropical orchid·oriental orchids (27.4%, 28.3%) on annual and peak season. And also, Charcoal and bonsai, which were unresponsive in the annual sales survey, increased sales volume to 0.7% and 2.6%, respectively, during peak season. Processed flowers were highest ranked dry flower (45.3%, 39.5%), preserved flower (27.7%, 37.2%) on both non peak season and peak season. And then followed by artificial flower, pressed flower and collage.

• Journal of the Korean Society of Floral Art and Design
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• no.43
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• pp.57-79
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• 2020

The purpose of this study was to investigate the effects of emotion and EEG of people with mental illness by vocational rehabilitation program based on horticultural therapy. The subjects of the study were three people with mental illness who were training in a vocational rehabilitation team at a health center located in G city, Gyeongsangbuk-do. The result of this study, positive affect increased and negative affect decreased. The result of EEG inspection was increased 17.27% on pre test to 21.39% on post test for Theta wave and 39.66% on pre test to 49.02% on post test for Alpha wave in case of subject A. Also Beta wave was decreased 27.53% on pre test to 17.54% on post test. Subject B increased Alpha wave 29.70% on pre to 31.82% on post. Subject C increased Alpha wave 26.30% on pre to 49.42% on post. Beta wave decreased 29.85% on pre to 16.13% on post. Theta wave, when creatively idea or thought occurs, alpha wave when safety and focusing was increased and beta wave when stress, tension and anxiety was decreased. As a result of profits analysis, subject A spent cost a total of 101,700 won for material and achieve profits of 203,400 won by setting a sales price. Therefore, gain the 101,700 won of net revenue. Subject B spent cost a total of 81,000 won for material and achieve profits of 162,000 won by setting a sales price. Therefore, gain the 81,000 won of net revenue. Subject C spent cost a total of 56,200 won for material and achieve profits of 112,400 won by setting a sales price. Therefore, gain the 56,200 won of net revenue.

• The Journal of the Acoustical Society of Korea
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• v.41 no.3
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• pp.278-286
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• 2022

In this study, a 33-mode Free-Flooded Ring (FFR) transducer was designed to apply piezoelectric single crystal PIN-PMN-PT, which has high piezoelectric constants and electromechanical coupling coefficient. To ensure low-frequency high transmitting sensitivity characteristics with a small size of FFR transducer, the commercial FFR transducer based on piezoelectric ceramics was compared. To develop the FFR transducer with broadband characteristics, a piezoelectric segmented ring structure inserted with inactive elements was applied. The oil-filled structure was applied to minimize the change of acoustic characteristics of the ring transducer. It was verified that the transmitting voltage response, underwater impedance, and beam pattern matched the finite element numerical simulation results well through an acoustic test. The difference in the transmitting voltage response between the measured and the simulated results is about 1.3 dB in cavity mode and about 0.3 dB in radial mode. The fabricated FFR transducer had a higher transmitting voltage response compared to the commercial transducer, but the diameter was reduced by about 17 %. From this study, it was confirmed that the feasibility of a single crystal-applied FFR transducer with compact size and high-power characteristics. The effectiveness of the performance prediction by simulation was also confirmed.

• Research in Plant Disease
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• v.28 no.1
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• pp.1-18
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• 2022

Volatiles exist ubiquitously in nature. Volatile compounds produced by plants and microorganisms confer inter-kingdom and intra-kingdom communications. Autoinducer signaling molecules from contact-based chemical communication, such as bacterial quorum sensing, are relayed through short distances. By contrast, biogenic volatiles derived from plant-microbe interactions generate long-distance (>20 cm) alarm signals for sensing harmful microorganisms. In this review, we discuss prior work on volatile compound-mediated diagnosis of plant diseases, and the use of volatile packaging and dispensing approaches for the biological control of fungi, bacteria, and viruses. In this regard, recent developments on technologies to analyze and detect microbial volatile compounds are introduced. Furthermore, we survey the chemical encapsulation, slow-release, and bio-nano techniques for volatile formulation and delivery that are expected to overcome limitations in the application of biogenic volatiles to modern agriculture. Collectively, technological advances in volatile compound detection, packaging, and delivery provide great potential for the implementation of ecologically-sound plant disease management strategies. We hope that this review will help farmers and young scientists understand the nature of microbial volatile compounds, and shift paradigms on disease diagnosis and management to aromatic (volatile-based) agriculture.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.13-26
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• 2022

Purpose : The purpose of this study was to investigate the effect of Dang Dang integrated corrective therapy including myofascial release, chuna therapy, and exercise therapy on height, muscle mass, body fat, and body water in patients with body imbalance. The secondary aim was to investigate whether the percent of change in height, muscle mass, body fat, and body water varied by age group. Methods : In total, 279 patients with body imbalance between the ages of 10 and 79 were recruited at hospitals. All participants had Dang Dang integrated corrective therapy including myofascial release, chuna therapy, and exercise therapy. The patients' height, muscle mass, body fat, and body water were measured before and after Dang Dang integrated corrective therapy using InBody. Results : The height, muscle mass, and body water significantly increased after Dang Dang integrated corrective therapy in all age groups except for the 70~79 age group and body fat significantly decreased (p < .05). The age group comparison of the percent change in height, muscle mass, and body water showed significant differences (p < .05). In the post hoc test, the percent change of height in the 10~19 age group was significantly greater than in the other age groups except for the 70~79 age group. The percent change of muscle mass and body water in the 10~19 age group was significantly greater than in the 30~39 age group. Conclusion : These findings suggest that applying Dang Dang integrated corrective therapy to patients with body imbalance, excluding patients aged 70~79, may be a useful method to increase height, muscle mass, and body water and decrease body fat through spinal and joint realignment. The best results were observed in teenagers.

• Journal of Adhesion and Interface
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• v.24 no.1
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• pp.26-35
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• 2023

Generally, solvent-type coatings generate a large amount of volatile organic chemicals(VOC), which are carcinogenic substances, in the manufacturing process, and their use is regulated due to environmental problems. There is also the problem of resource depletion due to limited fossil fuels. Therefore, in this study, UV-curable urethane acrylate oligomers were synthesized with different contents of isosorbide, which is a biomass material, and proceeded to evaluate the physical properties of coatings. As the isosorbide contents increased, the viscosity, glass transition temperature, tensile strength, stain resistance, and pencil hardness increased, but elongation and flexibility decreased, and BOI-3 showed the best adhesion. The isosorbide content of the oligomer fixed at 20%, UV-curable urethane acrylate oligomer was synthesized according to the content ratio of polycaprolactone diol(PCL) and Ecoprol H1000(Ecoprol). As the PCL/Ecoprol content ratio increased, the glass transition temperature, elongation, and flexibility increased, but the tensile strength and pencil hardness decreased. It was confirmed that the adhesion and stain resistance increased by improving the surface bonding strength of PCL. All films of oligomers synthesized were transparent without discoloration.

• Research in Plant Disease
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• v.29 no.3
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• pp.234-242
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• 2023

In early spring, water-soaked lesions appeared on the petals and leaves of gaenari (Forsythia koreana), and the tissues were necrotic and dry. Cankers appeared on the infected branches around late spring and the above part of a branch withered and died. However, it was very rare that the base of the cankered-branch died. The identical fungi were isolated from the lesions on various tissues, and they grew with white colonies on potato dextrose agar medium. The fungus grew most actively at 23℃ and produced many sclerotia of various sizes. In a pathogenicity assay in which mycelial and sclerotial suspensions were inoculated on each organ of forsythia, it was found that the pathogen infects the flower only, but not the leaves or branches. Symptoms on the flowers spread to the next leaves and branches over time and the infected branches were eventually withered. To identify the isolates, DNA sequences of four phylogenetic markers including ITS, LSU, Tub2, and CAL were analyzed and all isolates were identified as a species in the genus Septotinia. This is not only the first report of gaenari (forsythia) shoot blight caused by the fungus Septotinia sp., but also the first report on the genus Septotinia as a plant pathogen in Korea.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.153-160
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• 2009

Objectives : The purpose of this study was to investigate the anti-inflammatory effects of extract from Trogopterorum Faeces (TF) on the RAW 264.7 cells. Methods : To prove the TF's anti-inflammatory effects, we investigated nitric oxide (NO) production and own cell viability. We examined the cytokine productions on lipopolysacchride (LPS)-induced RAW 264.7 cells and also cellular regulatory mechanisms. Results : TF does not have any cytotoxic effect. TF reduced LPS-induced NO production, interleukin (IL)-1b, IL-6, IL-10 and tumor necrosis factor-a (TNF-a) in RAW 264.7 cells. TF inhibited the activation of mitogen-activated protein kinases (MAPKs) such as p38, extracelluar signal-regulated kinase (ERK 1/2) and c-Jun NH2-terminal kinase (JNK) and also the degradation of inhibitory kappa B a (Ik-Ba) in the LPS-stimulated RAW 264.7 cells. TF reduced the serum levels of IL-1b, IL-6, TNF-a. The survival rate of LPS-induced endotoxin shock was increased by TF administration. Conclusions : TF down-regulated LPS-induced NO and cytokines production, which could provide a clinical basis for anti-inflammatory properties.

• Research in Plant Disease
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• v.29 no.1
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• pp.52-59
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• 2023

Cucurbit chlorotic yellows virus (CCYV) is a plant virus that causes damage to cucurbit crops such as watermelon and cucumber, and is transmitted by an insect vector known as the whitefly. Since CCYV was first detected on cucumber in Chungbuk in 2018, it has been reported in other areas including Gyeongsang in Korea. In 2020, we performed field surveys of yellowing diseases in the greenhouses growing melon and watermelon in Chungbuk (Jincheon and Eumseong). Reverse transcription-polymerase chain reaction analysis of 79 collected samples including melon, watermelon, and weeds resulted in detection of CCYV in 4 samples: Three samples were singly infected with CCYV and one samples was mixed infected with CCYV, Cucurbit aphid borne yellows virus, and Watermelon mosaic virus. The complete genome sequences of the four collected CCYV melon isolates (ES 1-ES 4) were determined and genetically compared with those of previously reported CCYV isolates retrieved from GenBank. Phylogenetic analyses of RNA 1 and 2 sequences revealed that four ES isolates were clustered in one group and closely related to the CCYV isolates from China. The analysis also revealed very low genetic diversity among the CCYV ES isolates. In general, CCYV isolates showed little genetic diversity, regardless of host or geographic origins. CCYV has the potential to pose a serious threat to melon, watermelon, and cucumber production in Korea. Further studies are needed to examine the pathogenicity and transmissibility of CCYV in weeds and other cucurbits including watermelon.