• 한국조경학회지
• /
• 제32권5호
• /
• pp.43-51
• /
• 2004

Recently, the importance of choosing correct pavement materials has been increasing in urban spaces and streets. Much research regarding the pavement theory and construction method have been conducted, but analysis in terms of human psychological character has not yet been performed. The purpose of this study is to investigate the psychological characters to 12 pavement materials, that are commonly used in our urban spaces and streets. The results of the psychological character for each pavement material can be summarized as follows: 1. The psychological characters to each pavement material were as follows: ① Clay embodies a natural, traditional, soft and intimate psychological character; ② Pebble stone has a natural, hard, cool and intimate psychological character; ③ Turf grass incorporates an intimate and soft psychological character; ④ Ceramic brick has an artificial and hard psychological character; ⑤ Tile pavement has a modern, artificial, hard and cool psychological character; ⑥ Water permeable concrete has a modern and artificial psychological character; ⑦ Flag stone has a natural psychological character; ⑧ Granite has a modern and artificial psychological character; ⑨ Portland concrete has an artificial and hard psychological character; ⑩ Small compacted brick has an artificial, dynamic and modern psychological character; ⑪ Wood block pavement has a natural and traditional psychological character; ⑫ Asphalt concrete pavement has a modern, hard and artificial character. 2. On the results of the cluster analysis regarding psychological indexes for 12 pavement materials, pavement materials were categorized in 3 clusters. Among them, one cluster was mainly used as the most popular pavement material in our urban spaces and streets. From this point of view, psychological character for pavement material in our urban spaces and streets was not as various as we expected. 3. In conclusion, the proper selection of pavement materials was very important and the factors affecting the human psychological character should be considered in the design of urban spaces and streets.

• 한국작물학회지
• /
• 제54권3호
• /
• pp.320-326
• /
• 2009

우리나라 재래 수집종인 제비콩, 갓끈동부와 쥐눈이콩은 종피가 매우 두껍고 딱딱하여 물 흡수가 어려워 발아율이 각각 26%, 17%와 5%에 불가하다. 이들 종자는 저장성에서 그 가치가 높이 평가되지만, 포장에 파종할 때 발아율이 낮아 문제가 되고 있다. 본 연구에서는 이들 종자의 발아율을 향상시키기 위하여 몇 가지 종피약화 처리를 실시하여 가장 효과적인 방법을 도출하였다. 종피약화 처리방법 중 가장 정상묘율이 높은 것은 제비콩은 tap water ($20^{\circ}C$)에서 24시간 침지 했을 때 85%이였으며, 갓끈동부는 hot water에서 8시간 침지했을 때 45%이였다. 그러나 소립이고 경도가 높은 쥐눈이콩은 진한 sulfuric acid에 10분간 침지 했을 때 72%의 정상묘율을 보였다.

• 대한기계학회논문집B
• /
• 제29권11호
• /
• pp.1229-1238
• /
• 2005

The objective of the present study was to investigate the efficacy of physical water treatment (PWT) technologies using different catalytic materials and an electronic anti-fouling device in the mitigation of mineral fouling in a once-through flow system with mini-channel heat exchanger. Effects of flow velocity and water hardness on the effectiveness of PWT technologies were experimentally studied. The artificial water hardness varied from 5.0 to 10 mo1/m$^{3}$ as CaCO$_{3}$. For 10 mo1/m$^{3}$ solution, fouling resistance reduced by 13-40$\%$ depending on flow velocity and types of PWT devices. On the other hand, fouling resistance reduced by 21-29$\%$ depending on the PWT devices for 5 mo11m3 solutions. The PWT device using alloy of Cu and Zn as catalyst (CM2) was slightly more effective than the others. SEM photographs of scale produced from the 10 mol/m$^{3}$ solution at 1.0 m/s indicated that calcium carbonate scales without PWT devices were needle-shaped aragonite, which is sticky, dense and difficult to remove. Scales with the PWT devices showed a cluster of spherical or elliptic shape crystals. Both the heat transfer test results and SEM photographs strongly support the efficacy of PWT technologies using catalytic materials and an electronic anti-fouling device in the mitigation of mineral fouling.

• 한국작물학회지
• /
• 제51권1호
• /
• pp.59-65
• /
• 2006

The impermeable seed coat is valuable trait in soybean because impermeable seed retain viability for longer period than permeable seed under adverse conditions such as delayed harvest or prolonged storage. Soybean seeds of various size showing different seed hardness were examined for their water absorption and seed viability under adverse storage conditions. Of one hundred thirty nine genotypes, eight types of seeds having different seed hardness and seed size were used as material. Soybean genotypes showing high hard seed rate, GSI13125 (89%), GSI10715 (54%), and GSI10284 (42%), were slow in water absorption and low in the electroconductivity of seed leachate in distilled water. Germination of GSI10284 and GSI13125 that have higher hard seed rate was less affected by CSVT and artificial aging treatment indicating higher seed storability. The higher storing ability of both collections was confirmed by electroconductivity test for leachate. GSI10122 showed low seedling emergence when the seeds were artificially aged. This genotype was considered as to having a poor storing ability based on difference of electroconductivity before and after artificial aging. Among tests conducted in the experiment, CSVT could be used for determining storage life in legumes. In conclusion, water absorption property of seed was strongly related to the hardness that is directly related to the seed viability and storing ability in soybean seed.

• 한국정보통신학회논문지
• /
• 제26권7호
• /
• pp.963-971
• /
• 2022

상수도 관망은 국가 수도 시설의 주요한 구성 요소이지만 대부분이 지중에 매립되어 있어 배관의 노후화 정도 및 누수를 파악하기 어려우므로 유지관리 하기가 매우 어렵다. 본 연구에서는 관망에 설치된 다양한 센서 조합을 가정하여, 데이터 조합에 따른 관로 누수 판별 가능성을 검토하기 위하여 선형회귀분석, 뉴로퍼지 등의 인공지능 알고리즘을 통한 유량과 압력 예측을 실시하여 최적 알고리즘을 도출하였다. 공급압력 예측을 통한 누수판별의 경우 뉴로퍼지 알고리즘이 선형회귀분석에 비하여 우수하였다. 누수유량 예측에서는 뉴로퍼지를 이용한 유량예측이 우선 고려되어야 한다. 다만, 유량을 모사하기 힘든 경우에는 선형 알고리즘을 이용한 공급압력 예측이 이루어져야 할 것으로 사료 된다.

• 한국패류학회지
• /
• 제26권2호
• /
• pp.151-156
• /
• 2010

본 연구는 말백합 산업화를 위하여 어미성숙 관리한 인위성숙개체군과 시기별로 어미를 수송 채란한 자연성숙개체군을 산란유발 방법 별로 산란을 유도하여, 수정율, 부화율, D형 유생 발생률을 조사하였고, 유생사육 방법별로 유생의 성장과 생존율 등을 조사하였다. 인위성숙개체군의 간출시간별로 산란 유도한 결과 간출 4시간 및 8시간이 반응률이 23% 및 32%로 비교적 높았고, 수온 상승별로는 $28^{\circ}C$ 이상 되어야 반응이 시작되었다. 간출 및 수온상승 병행 시험구에서는 간출 4시간 및 $28^{\circ}C$에서 반응률이 45% 이상으로 나타났고, 29, 30, $31^{\circ}C$에서는 유의한 차이를 보이지 않아 말백합 어미는 간출시간보다는 수온상승에 반응률이 높은 것으로 나타났다. 어미수송개체군의 시기별 산란유발 결과는 2009년 8월 6일이 반응률 67.6%, D형 유생 발생률이 96%로 가장 높게 나타났다. 유생사육 시험 중 수온별로는 유생의 성장과 생존율을 고려할 때 유생사육 적정수온은 $27-31^{\circ}C$, 최적수온은 $29^{\circ}C$로 나타났고, 염분은 25에서 성장 및 생존율이 비교적 높았으며, 수용밀도별로는 5 inds./mL에서 성장 및 생존율이 비교적 높게 나타났음을 알 수 있었다.

• 환경생물
• /
• 제35권2호
• /
• pp.152-159
• /
• 2017

For the effective seedling production of the hard shelled mussel, Mytilus coruscus, this study assessed the effects of the dietary value of live food, density, water temperature and salinity on growth and survival rate of the larvae. The optimal survival rate and growth rate were examined under differing conditions of water temperature, salinity, and rearing density for 30 days. The three groups were provided different feeding organisms, such as Isochrysis galbana and Teleaulax suecica. The mixtures were provided at a rate of $5{\times}10^4cell\;mL^{-1}$. The best growth was observed in the group with conditions $21^{\circ}C$ water temperature ($16.2{\pm}9.1{\mu}m$), 33 psu of salinity ($16.82{\pm}3.9{\mu}m$), $2500individual\;m^{-2}$ ($17.2{\pm}5.9{\mu}m$), and fed with $5{\times}10^4cell\;mL^{-1}$ of I. galbana and T. suecica mixture ($16.0{\pm}7.3{\mu}m$). The highest survival rate was found in the group at conditions $18^{\circ}C$ water temperature (66.4%), 33 psu of salinity (24.4%), $2500individual\;m^{-2}$ (65.8%), and fed with $5{\times}10^4cell\;mL^{-1}$ of I. galbana and T. suecica mixture (58.8%). We therefore conclude that the suitable culture conditions for the stable production of hard shelled mussel artificial seedlings was at 18 to $21^{\circ}C$ of temperature, 30 to 33 psu of salinity, 2500 to $5000individual\;m^{-2}$ of rearing density, and feeding supplement of $5{\times}10^4cell\;mL^{-1}$ of I. galbana and T. suecica mixture under semi running water system.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2000년도 춘계학술대회논문집B
• /
• pp.180-186
• /
• 2000

This paper presents a new winding method in the electronic descaling(ED) technology. The ED technology Produces an oscillating electric field via the Faraday's law to Provide necessary molecular agitation to dissolved mineral ions. But present method gives another agitation force to mineral ions, which is Lorentz's force. Experiments were peformed at various Renolds number. A series of tests was conducted, measuring pressure drop across test section and the overall heat transfer coefficient as a function of time. In order to accelerate the rate of fouling, artificial hard water of 1000ppm $CaCO_3$ was used throughout the tests. The results show that the new method accelerates collision of mineral ions and improvs efficiency of system.

• 한국세라믹학회지
• /
• 제53권2호
• /
• pp.241-245
• /
• 2016

The purpose of this study was to investigate the bloating mechanism of artificial lightweight aggregates with different sizes (ESA, effective surface area). Aggregates were produced using hard clay, stone sludge, and a bloating agent in order to observe the effect of the gradation of the artificial lightweight aggregates. Kerosene and amorphous carbon were used as bloating agent. The particle size of the produced aggregate ranged from 3 mm to 9 mm. With regard to the amount of bloating agent to be used, 2 ~ 6 parts by weight were used. The specific gravity, absorption rate, and the type of aggregates produced by rapid sintering at $1075{\sim}1200^{\circ}C$ were determined. Microstructures were observed. When ESA had a value of 1 or below, kerosene, which has a high burning rate, was found to be advantageous for use as a bloating agent. When ESA had a value of 1 or above, carbon, which has a relatively low burning rate was found to be an advantageous bloating agent. It is thought that kerosene is more advantageous, as ESA decreases, for the production of aggregates having low water absorption rate.

• 한국습지학회지
• /
• 제11권3호
• /
• pp.145-151
• /
• 2009

현재까지 국내의 수질관리 정책은 점오염원 관리를 우선시 하고 있다. 그러나 계속되는 점오염원의 관리에도 불구하고 호소수의 수질은 악화되고 있다. 비점오염원은 강우 시 발생하는 오염원으로 토지이용에 따라 발생하는 오염물질의 종류와 양이 달라 불확실성이 큰 오염원이므로 점오염원과 함께 비점오염원의 관리가 필요한 실정이다. 다양한 토지이용 중에서 인공초지(공원 묘지) 지점이 차지하는 비율이 낮기 때문에 원단위를 산정하는데 필요한 기초 데이터에 대한 연구가 전무한 상태이다. 따라서 본 연구는 인공초지(공원 묘지) 지점으로부터 강우 시 유출수와 함께 발생하는 비점오염물질의 유출특성 및 상관성을 파악하였다. 그 결과 강우 초기에 오염물질의 농도는 비교적 높게 유출되는 현상을 나타냈으며, 강우가 지속될수록 오염물질의 농도는 감소하는 것으로 나타났다. 그러나 첨두유량이 발생하면서 유출농도는 증가하였다. 또한 통계분석을 실시한 결과 오염물질별 상관성이 거의 없는 것으로 나타났다. 이러한 결과는 향후 부하량과 원단위 산정에 필요한 기초자료로 활용될 수 있을 것으로 기대된다.