연구논문 : 분수에서 생성되는 물입자의 확산과 냉각효과의 범위 예측

이상득 한국환경과학회 2011 한국환경과학회지 Vol.20 No.7

This research was done to clarify the cooling effect of water particles generated from a fountain. This effect is a one way to control the heat island effect of big cities. The result of this research was drawn by setting the jets of water in a certain height, and then studying the diffusion of water particles, which is affected by the size of the particles and the wind speed, and the cooling effect caused by the diffusion. 1) When a diameter of a water drop was 500㎛ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 75 to 190m, and the water vapor spread over 175 to 440 m. As a result, there was more than 0.5℃ of cooling effect on the temperature in the atmosphere 130 to 330m around the water fountain. 2) When a diameter of a water drop was 750㎛ and the wind speed was 2.0 to 6.0 m/sec, the water drop diffused 65 to 150 m, and the water vapor spread over 160 to 405 m. Moreover, there was more than 0.5℃ of cooling effect on the temperature in the atmosphere 110 to 275 m around the water fountain. 3) After studying on the relationship between the diameter of water drop and the wind speed, and the diffusion of water particles and the range of the atmosphere that was cooled, a result could be drawn from the research that the smaller the diameter of the water vapor gets and the faster the wind speed becomes, the wider the water particles diffuse and the cooler the atmosphere around the fountain becomes. 4) This research further extrapolates that when the ordinary water(tap water, water from river and stream) is used in a fountain, the cooling effect of the air near the fountain can be approached similarly. If the seawater is used in a fountain, there is to be more to concern not only on cooling effect on the air, but also on other effects on surrounding environment generated by the salt in seawater.

Optimization System of Musical Expression for the Music Genre Classification

Seung-Min Park,Junheong Park,Kwee-Bo Sim 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

Recently, the introduction of CT (Culture Technology) in the intelligence system was forming a new paradigm. Among these, research on musical fountain is still in the basic research phase has been started. Musical fountain System is required scenario to control the music and nozzle of fountain. In generally, these musical fountain scenarios created by the experts. So musical fountain need too much cost of maintenance for subsidiary facilities. In this paper, using the Beat Tracking Algorithm, optimized musical expression intelligent fountain system is proposed. Also, we proposed new classification of music genre to reduce the maintenance costs of musical fountain. We simply tag the emotional adjectives, as set apart as a genre of music was re-classified. In this paper, the newly defined criteria to classify the genre, SVMs (Support Vector Machines) algorithm, the weights applied by the Gaussian distribution to determine the optimal hyper plane, VCMs (Variance-Considered Machines)algorithm is used. The proposed use of this system to generate a musical fountain scenario can significantly reduce the time required, a in terms of cost can be reduced significantly.

주거단지 분수 연출음의 선호특성을 고려한 설계방안에 관한 연구

신용규,국찬 한국소음진동공학회 2020 한국소음진동공학회 논문집 Vol.30 No.3

This study describes the efficient design of fountains using choreographed music and also the design of natural water sounds to identify the physical characteristics of the preferred sound source in hydroponic spaces in residential complexes. According to the study results, REm, NbEm, sharpness, StdDev, and G indices represent the choreographed music and sound of water generated by spraying from the nozzle of the fountain. According to the type of fountain nozzle, type of floor on which the water falls after being sprayed from the nozzle, and the method of creating hydroponic space, such as water flow, the characteristics of the index for preferred sound source could be identified. In addition to the lexical evaluation of sound sources for the sound of fountains and natural waters, it was possible to classify the characteristics of the sound sources into eight lexica choreography senses and nine lexica natural senses for natural water sounds. If additional sound sources are obtained in an environment, where nozzle types of fountains can be diversified and combined in the future. Subjective evaluations are verified through brainwave evaluation in a laboratory environment optimized for brainwave testing and water sound production. It is expected that the design method of optimized fractions for residential complexes will be presented and applied if additional sound sources are obtained in an environment for which nozzle types of fountains can be diversified and combined in the future.

분수대에서의 전기설비 고장에 대한 누전 감지 장치 개발

김두현,김성철,박종영 한국안전학회 2018 한국안전학회지 Vol.33 No.1

This research aimed to develop an leakage detector of analyzing the electric potential generated from the electric leakage of electric equipment of the fountain. To accomplish this goal, the potential gradient was analyzed against path 1 ~ path 4; this was done by taking the lighting of a fountain as the electric leakage point based on code analyses in Korea and other countries. Lighting 1 was taken as the electric leakage point, and the earthing point was set against lightings(2~3). It appeared that the allowable touch voltage against the 1 type(under 2.5 V) exceeded 60.0%. Therefore, the lighting of fountain turned out to be the most dangerous point, and electric shock could be formed by the electric leakage of electric equipment in underwater as well as by the lighting. An leakage detector was developed based on this risk; this detector is capable of analyzing the electric potential of a electric equipments of the fountain in underwater. Then, a verification test was carried out. This leakage detector can be used to measure electric potential in various submerged areas such as swimming pools, flooded spaces, and fountains.

물소리와 분수 연출음의 물리적 특성에 관한 연구

신용규,국찬 한국환경기술학회 2019 한국환경기술학회지 Vol.20 No.4

In this study, the sound of water and the physical characteristics of the reproducing sound of the fountain were identified and presented as basic data in the design of the fountain. First, the results of the study show that the physical index that can be described by dividing the space where water sounds are produced (W), the space where water sounds are not produced at all (N), and the space where water sounds and human behavior sounds coexist (C) was identified by StdDev, L90, NbEm, EmT, REm, G, and Sharpness. Second, the distinction between the number of nozzles in fountain and the water pressure could explain the sound quality (Loudness, Unbiased Annoyance, Articulation Index(NHV), Roughness), peak (REm, NbEm, StdDev) and size (Leq, L90) according to the change in the number of nozzles, and the clearness of the sound source (G, Sharpness) according to the change in water pressure, etc. Third, comparing the physical characteristics among the sound of water produced in space and the sound of the water directed by fountain resulted in consistent changes in StdDev, NbEm, and REm depending on the increase and decrease in the number of nozzles and G showed a tendency to change consistently with increasing or decreasing water pressure. So it is judged that the number of nozzles and the water pressure will allow the adjustment of a specific index. If the type of nozzle is further diversified and the hearing test and brain wave evaluation are carried out for field application, it will be possible to develop and utilize it as an indicator for the design of the fountain production according to location and situation.

바닥분수에서 물놀이를 하는 아동들의 Legionella균 감염 위해도 분석

이인섭,조영근,Lee, In-Sup,Zo, Young-Gun 한국미생물학회 2013 미생물학회지 Vol.49 No.4

최근 국내의 각종 시설들에서 경관과 여름철 물놀이를 위한 바닥분수 설치가 선호되어, 그 수가 연간 50% 이상 급증하고 있다. 본 연구는, 정량적 미생물학적 위해성 평가 방법으로, 아동이 바닥분수에서 물놀이를 하는 동안 Legionella spp.에 의한 감염 위해도가 어느 정도인지 정량 하였다. 용수 중 Legionella균의 농도를 $10^{-1}-10^6$ CFU/L로 상정하고, 공기 중으로 에어로졸과 함께 비산하게 되는 Legionella균의 농도와 노출시간, 호흡률의 분포, 폐까지 도달하는 에어로졸의 비율을 곱하여 아동들의 노출량을 산정하고, Legionella pneumophila의 위해도를 도출하는 것으로 알려진 지수함수 모델에 따라, 감염 위해도로 변환하였다. 최고 위험군은 뛰어다니면서 물놀이를 하는 신체가 큰, 혹은 연령이 높은 아동이었으며, 이들이 $10^4$ CFU/L 이상의 Legionella균이 존재하는 분수 용수를 1회 이상 이용 시 0.05 이상의 위해도가 발생하였다. 이 결과에 따르면, $10^3$ CFU/L 미만의 Legionella균 농도를 공중이용시설의 모든 배관용수에 대하여 허용하는 현행 질병관리본부의 레지오넬라증 관리지침은 타당한 것으로 판정된다. 그러나, 이 기준은 건강한 성인 대상으로는 적합하나 아동의 면역력이 낮은 점을 감안하지 않았으므로, 아동에게 적합한 감염위해도 모델을 연구하여, 보다 철저한 관리 기준을 적용할 필요성이 있다. Recently interactive water fountains are gaining popularity in making public facilities in South Korea. The total number of interactive fountains is rapidly growing at the rate of >50% annually. In this study, we performed quantitative microbial risk assessment to estimate infection risks in children by Legionella spp. while playing in interactive fountains. The exposure dose for a given concentration of Legionella in water was calculated using water-aerosol partition rate of Legionella, exposure duration, inhalation rate, and deposit rate of aerosols in the lungs following inhalation. The dose was converted to infection risk by using the dose-response function developed for L. pneumophila. High weight and/or old children, i.e., 12-year children, running around in fountains were the highest risk group by showing >0.05 infection probability for fountain waters containing ${\geq}10^4$ CFU/L Legionella. The result supported the current guideline by Korea Centers for Disease Control and Prevention, which permits use of water with < $10^3$ CFU/L Legionella cells for all purposes. However, the results still warrant further evaluation of the guideline to accommodate risks for children because the dose-response relationship in the model was developed for healthy adults. Further risk assessment studies need to be conducted by employing dose-response model for children who generally carries weaker immune system than adults.

Membrane Pumping을 이용한 Nano Fountain-Pen의 수치적 연구

이진형(Jin-Hyoung Lee),이명관(Young-Kwan Lee),이석한(Suk-Han Lee),김훈모(Hun-Mo Kim),김윤제(Youn J. Kim) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.11

Nano fountain-pen is a novel device to make the constant patterning in micro process using new designed probe. Fountain-pen nanolithography (FPN) is applied for constant supply of liquid in conjunction with local correction of patterns and surface variation in the micro process. Many studies for FPN are going on. Type of traditional probes is the multi-tip which can pattern by sub-micro unit. In this study, nano fountain-pen is made up reservoir, micro channels, tip and secondary chamber. Instead of traditional method only using capillary force, liquid can definitely and exactly inject with membrane pumping by repulsive force of tip. It is difficult to perform experiments in the micro range so that we carried out a new analysis for internal flow of nano fountain-pen with the membrane pumping, Using a commercial code, FLUENT, velocity, pressure and flow rate are obtained under laminar, unsteady and no-slip condition.

Analysis of an Acoustic Fountain Generated by Using an Ultrasonic Plane Wave for Dierent Water Depths

임수현,김무준,김정순 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.4

The control of ultrasonic atomization is important in its various application elds. Even though the acoustic fountain's shape is directly related to the quantity of atomized droplets, theoretical analysis of the shape has not been sucient. In this study, a theoretical analysis model for an- alyzing the fountain shape caused by ultrasound is suggested. The fountain shape was examined theoretically and experimentally for various input acoustic powers, radiation areas of the ultra- sonic transducer, and depths of the liquid. The results showed that the maximum height of the fountain for ultrasonic atomization occurred for a depth of 7 cm when the 1.5 cm diameter ultra- sonic transducer was driven by 2-MHz continuous wave in water. We conrmed that the suggested model provided the optimum liquid depth considering the eects of attenuation with increasing propagating distance of the ultrasound.

Fountain Code Design for Broadcasting Systems With Intermediate-State Users

Youngkil Suh,Jonghyun Baik,Rahnavard, Nazanin,Heo, Jun Institute of Electrical and Electronics Engineers 2015 IEEE Transactions on Communications Vol. No.

<P>Several studies on fountain codes have proposed degree distribution optimization schemes to maximize symbol recovery rate. However, if the number of transmitted coded symbols is limited or the channel erasure probability is high, it may be impossible that a user recovers all of the data symbols regardless of degree distribution employed by the source. In this study, we focus on a new system model where one source transmits fountain-coded symbols to multiple users who already possess some data symbols and coded symbols. Assuming that each user can transmit a feedback packet containing its own state information before the source transmits coded symbols, we propose two types of degree distribution design schemes that are suitable for the system model. Simulation results demonstrate the efficiency of our proposed schemes by comparing with conventional methods in terms of symbol recovery rate and full recovery rate.</P>

물놀이형 수경시설의 수질과 항생제 내성 대장균 분포에 관한 연구

윤상훈,김선경,김난희,위환,이세행,조광운,김동수,조영관,Yoon, Sang-Hoon,Kim, Seon-Gyeong,Kim, Nan-Hee,Wi, Whan,Lee, Se-Hang,Jo, Gwang-Woon,Kim, Dong-Su,Cho, Young-Gwan 한국환경보건학회 2014 한국환경보건학회지 Vol.40 No.3

Objective: This study was performed in order to investigate the distribution of antibiotic resistant E. coli and water quality in waterscape facilities. Methods: Nine waterscape facilities were selected and classified into three types: ground, wall and general fountain. The items analyzed in this study were pH, turbidity, $KMnO_4$ consumption, total colony, total coliforms, fecal coliforms and E. coli. Additionally, an antibiotic resistance test on E. coli was performed. Results: There were no sampling sites that exceeded the permitted limits of water quality, but the concentration of pollutants was high at the beginning operation in June. Moreover, concentration of turbidity, $KMnO_4$ consumption and total colony were higher in ground fountains than in wall and general fountains. Five species of antibiotic resistant E. coli were detected from three sampling sites. Conclusions: The waterscape facilities were significantly contaminated with water microorganisms, especially total colony, total coliforms and fecal coliforms. Disinfection and filtration systems to remove pollutants should be installed for safe waterscape facilities.