• Journal of Korean Association for Spatial Structures
• /
• v.8 no.3
• /
• pp.53-63
• /
• 2008

In this study, the reverberation characteristics of coupled spaces were investigated using a scale model. Two rooms were connected through an acoustically transparent opening known as an aperture. The acoustic characteristics of the coupled room by varying three parameters, the aperture opening size, the absorption ratio between the two rooms and the locations of the secondary room, were measured and analysed. The results indicated that a reverberant secondary room, produced large variations of the acoustics in the main room and an absorptive secondary room was effective to provide systematic control of the acoustics in the main room. The reverberant secondary room should be located at the rear of the stage and the aperture opening ratio over 6.25% produced large variations of the acoustics in the main room. However, the aperture opening ratio over 25% had no effect on variations of the acoustics in the main room. The absorptive secondary room should be located at the rear of the audience areas and the aperture opening ratio over 3.13% produced large variations of the acoustics in the main room.

• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.08a
• /
• pp.60-60
• /
• 2020

본 연구는 수확 단계에 따른 작약 주요 품종의 수확후 품질 특성을 조사하여 품종별 적정 수확 시기를 구명하고자 수행하였다. 절화 작약은 '두체스', '레드참', '보울오브크림' 품종을 사용하였으며, 세 품종 모두 1, 2, 3, 4단계로 구분 지어 수확하여 실험에 사용하였다. 수확한 작약은 40cm로 재절단하여 chrysal professional III 용액이 담긴 화병에 꽃아 생체중, 증산량, 수분흡수량, 개화 단계 변화 등을 매일 조사하였고, 이를 통해 수분균형 및 절화 수명 등의 결과를 도출하였다. '두체스' 품종의 품질 특성 변화를 조사한 결과, 1단계에 수확한 절화의 만개소요일수는 5.5일, 만개유지일수는 2.9일, 총 절화수명은 8.4일로 다른 수확단계보다 1~3일 더 긴 것으로 조사되었으며, 생체중증가율 및 화경 변화 결과를 통해 1단계 수확 시에도 개화는 정상적으로 진행되는 것을 확인할 수 있었다. '레드참' 품종의 품질 특성 변화 조사 결과, 1단계에 수확한 절화의 만개소요일수는 7.9일, 만개유지일수는 3.3일, 총 절화수명은 11.2일로 다른 수확단계보다 1~4일 더 긴 것으로 조사되었다. '보울오브크림' 품종의 품질 특성 변화 조사 결과, 1단계 수확한 절화는 30% 수준만 만개하여 조기 수확에 따른 문제점이 확인되었지만, 2단계 수확한 절화는 개화와 만개 모두 100% 진행되었으며, 만개소요일수는 6.4일, 만개유지일수는 4.5일, 총 절화수명은 10.9일로 다른 수확단계보다 1~2일 긴 것으로 조사되었다. 본 연구 결과, '두체스' 와 '레드참' 품종의 적정 수확단계는 1단계, '보울오브크림' 품종의 적정 수확단계는 2단계가 적절할 것으로 판단된다.

• Journal of dental hygiene science
• /
• v.16 no.6
• /
• pp.458-463
• /
• 2016

This study aimed to assess changes in maximum bite force and psychological elements in patients with bruxism treated with botulinum toxin who visited the hospital with a chief complaint of masseter hypertrophy. From among the subjects with masseter hypertrophy as the chief complaint, 10 patients with and 10 without bruxism were selected. We measured bite force prior to botulinum toxin injection and at 2, 4, 8, and 12 weeks after the injection and assessed changes in psychological elements by using Symptom Checklist 90 Revision. The study results showed statistically significant differences in maximum bite force on both the right and left sides between the patients with and those without bruxism, according to periodic changes (p<0.05). Depression elements showed statistically significant changes in the patients with bruxism (p<0.05). In the bruxism and non-bruxism groups, the patients recovered from anxiety in accordance with the periodic changes (p<0.05). Our study results indicate that the patients with bruxism show significant changes in interpersonal sensitivity, depression, and anxiety according to the treatment periods, and that occlusal force and depression were significantly related. Therefore, when setting a treatment plan for bruxism, multilateral psychological elements must be considered, along with functional elements.

• Journal of Environmental Impact Assessment
• /
• v.32 no.6
• /
• pp.407-418
• /
• 2023

This study conducted an analysis of terrain change indicators in major development projects in Korea, examining the correlation between terrain change indicators to derive foundational terrain change metrics based on different land use and slope types. The aim is to contribute to sustainable development by enhancing the efficiency of land utilization and landscaping, while minimizing environmental impacts in future development endeavors. Additionally, to apply the research findings in practical contexts, domestic regulations related to terrain were surveyed, and the compatibility and usability between these regulations and research analysis results were discussed. Based on this, the study seeks to explore strategies for more accurate and useful utilization of terrain change indicators in future research. As a result, in the tourism development, terrain changes predominantly occur in the order of flat land, hillly land, and mountain land, with the analysis indicating higher terrain changes in undulating hilly and mountainous lands compared to flat land. Furthermore, in industrial complex development, very steep (20°-30°) and extreme (30°-40°) slopes; in urban development projects, steep slope (15°-20°); in athletic service facility and tourist development, steep (15°-20°) and very steep (20°-30°) exhibit higher average terrain change indicators compared to other slope categories. The findings of our study can contribute to the formulation of strategies aimed at minimizing terrain disturbance in future domestic development projects and serve as foundational data for environmental impact assessments.

• Korean Journal of Environmental Biology
• /
• v.33 no.1
• /
• pp.53-62
• /
• 2015

We surveyed butterfly community in a rural area of the southwestern part of Korea to investigate the changes of species composition and their abundances between 2001~2002 and 2014. The butterfly survey was conducted at the same site using a line transect method. There was a significant decrease of the numbers of species and individuals between 2001~2002 and 2014. We categorized each species based on six ecological traits: habitat type, habitat breadth, food plant type, food plant breadth, number of generation per year and overwintering stage. The comparison of number of species using these ecological traits showed no difference during the 10-yr time intervals. However, the comparison of number of individuals for the ecological traits showed the significant differences except for one trait, overwintering stage. We could suspect that the decrease of butterflies in the study area was resulted from the habitat change. To investigate the causal factors and the changes of butterfly fauna, we need a long-term monitoring of the local butterfly community.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2009.05a
• /
• pp.198-202
• /
• 2009

기후변화는 강수와 기온을 변화시켜 수자원에 지대한 영향을 미칠 것으로 알려져 있다. 따라서 이에 대한 안정적인 수자원 관리를 위해서는 기후변화 영향을 정량적으로 평가하는 것이 필요하다. 기본적으로 기후변화에 대한 수자원의 영향을 연구할 때 '온실가스 배출시나리오, GCMs을 통한 기후모의, 시공간적 편차보정을 위한 상세화, 유출모형 적용을 통한 유출시나리오 생산'의 과정을 거친다. 그러나 유출시나리오를 얻기까지 과정에는 각각 불확실성을 가지고 있기 때문에 최종결과의 불확실성은 각 과정을 거치면서 매우 커진다고 할 수 있다. 다양한 배출시나리오, GCM 결과, 유출모형에 대해 단순평균 혹은 가중치를 주는 multi-model ensemble 기법은 각 경우에 따른 값의 범위를 제시할 수있다는 점 때문에 불확실성 평가에서 주로 이용되고 있다. 본 연구에서는 우리나라 5대강 유역 109개 중권역에 대해 multi-model ensemble을 적용하여 기후변화에 의한 수자원 영향을 평가하였다. 1971년에서 2100년까지 120년 기간에 대해 3개의 온실가스 배출시나리오, 13개의 GCMs 결과들을 수집하여 총 39개의 기후시나리오를 이용하였고, 이를 8개의 유출모형에 적용하여 총 312개의 유출시나리오를 생산하였다. 생산된 유출시나리오를 기준시간(1971${\sim}$2000)에 대한 미래의 세 기간(2020s, 2050s, 2080s)으로 나누어 변화율을 분석한 결과 여름철 유출량과 겨울철 유출량이 증가될것으로 나타났으나 겨울철 유출량 전망은 여름철에 비해 불확실성이 큰 것으로 나타났다. 공간적으로는 한강유역이 위치한 북쪽유역이 남쪽에 비해 불확실성이 큰 것으로 나타났다. 결과적으로 유출의 시공간적 편차에 의해 우리나라 수자원은 홍수피해 증가가 예상되었으며, 월별유출량의 변화로 인해 용수확보와 관리에 어려움이 증가할 것으로 전망되었다.

• Journal of Science Education
• /
• v.38 no.2
• /
• pp.430-442
• /
• 2014

The purpose of this study is to investigate the Preconception about the causes and consequences of climate change. Participants were 196 High school students who live in Seoul and Gyeong-gi Province. And data was collected through questionnaire to confirm preconception about the causes and consequences of Climate Change. After confirming with students preconceptions, 10 people randomly selected and Semi-structured interview were conducted. The findings is students did not know exactly about Ozone depletion, global warming, the greenhouse effect factors and causal relationships. And we can confirm that the student's preconception is affecting.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.125-125
• /
• 2019

현재 국내 논벼 수요량 산정방법은 수정 Penman방식에 의한 증발산량을 계산하여 구하고 있다. 증발산량 산정은 여러 가지 방식에 의해 산정될 수 있으나, 유엔의 식량농업기구 (FAO, Food and Agriculture Organization of the United Nations)에서는 작물 수요량 산정에 수정 Penman 공식을 사용할 경우 증발산량이 과다산정 되는 점을 지적하여, 건조 및 습윤 기후에서 비교적 정확하고 일정한 경향을 나타내는 Penman-Monteith(P-M)공식을 사용하도록 추천하였다. 이에 따라 국내 기상청 및 농촌진흥청에서도 증발산량 산정에 P-M공식을 적용하기 시작했으며, 이와 더불어 농촌진흥청에서는 P-M 추정법에 따른 벼를 포함한 주요 작물의 생육단계별 작물계수(Kc)를 제안하였다. 따라서 본 연구에서는 논용수 공급지구 8곳을 선정하여 대상지구별로 기존의 수정 Penman 방식과 P-M 방식을 적용한 경우의 증발산량 차이와 이에 따른 논벼 수요량 변화를 분석해 보았다. 그 결과, 수정 Penman 공식을 적용한 경우에 비해 P-M공식을 적용한 경우 증발산량이 모두 감소하는 경향을 나타내었다. 증발산량 산정방법 변화에 따른 대상지구별로 증발산량 결과값의 변화는 모두 비슷하게 나타났다. P-M방식을 적용했을 경우 잠재증발산량은 11.1%~14.9%(평균 12%)로 감소하였으며, 작물계수를 적용한 실제증발산량의 경우에도 3.8~5.1%(평균 4.6%) 감소하는 경향을 보였다. 이에 따른 논벼 수요량의 변화도 실제증발산량의 변화와 비슷한 감소 경향을 보였다. 다음으로 P-M방식을 채택한 경우의 논벼 수요량의 생육시기별 변화를 조사해 본 결과, 이앙기 수요량은 2.1%~6.3% (평균 4.4%)로 증가하다가, 본답기에는 수요량이 5.1%~11.3%(평균 8.4%)로 감소하였다. 전반적인 증발산량은 본답기 수요량 감소분이 이앙기 수요량 증가분보다 더 크기 때문에 감소경향을 나타낸 것으로 파악되었다. 또한 이앙기 수요량과 본답기 수요량의 증감의 경향이 다르게 나타난 것은 증발산량 산정방식의 변화에 따른 생육시기별 작물계수의 차이로 인한 변화로 파악되었다. 논벼 수요량은 농업용수 공급계획 수립의 주요기준이 되는 인자이므로, P-M방식 적용에 따른 논벼 수요량의 산정결과에 대해 보다 면밀한 검토가 필요할 것으로 사료된다.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.2
• /
• pp.378-387
• /
• 2017

To stabilize the supply of kimchi by extending the storage period of spring kimchi cabbage, this study manufactured kimchi from spring kimchi cabbage under varying storage conditions and periods, and analyzed their quality and sensory characteristics following the maturing period. Trimming loss was lowest in the group of plasma+reverse direction+predrying+HDPE film processing. The salting yield of spring kimchi cabbage stored for 12 weeks was lower than that of spring kimchi cabbage stored for 6 weeks, and the kimchi yield was low in the pre-treatment group of spring kimchi cabbage stored for 12 weeks. The firmness was slightly different according to the storage period from one month of maturation. From the perspective of pH and acidity, the maturation in the reverse direction+pre-drying+HDPE film processing group was slower than that in the normal group (<0.05). In the sensory evaluation, the preference was increased in the low temperature storage processing group as the maturation period was increased (<0.05).

• Journal of Dental Rehabilitation and Applied Science
• /
• v.27 no.2
• /
• pp.185-195
• /
• 2011

In this study, titanium abutments and zirconia abutments were connected to each implant in external type implants. After that they were loaded 10000 times with 20Kg as occlusal force. The surface changes of external hexgon part and platform were observed in FESEM image. Viker's hardness of an implant, a titanium abutment and a zirconia abutment were measured respectively. 1. Viker's hardness of an implants, a titanium abutment and a zirconia abutment was $309.80{\pm}11.78$ HV, $318.40{\pm}11.82$ HV, and $1495.30{\pm}16.21$ HV respectively. There was no statistical significance between an implant and a titanium abutment (P>0.05, Anova). However, there was statistical significance between an implant and a zirconia abutment(P<0.05, Anova). 2. The wear was observed at the joint of implant and abutment in both a titanium abutment group and a zirconia abutment group after loading 10,000 times. The zirconia abutment showed more remarkable wear than the titanium one. In conclusion, the wear of external hexagon and platform was much more notable in a zirconia abutment group than a titanium one. It was suggested that it could result from the difference of surface hardness between titanium and zirconia. The wear of junction between an implant and a zirconia abutment becomes more severe, the connection of an implant and an abutment is much more unfit. This is likely to cause loosening and fracture of the abutment screw. so it is considered that the possibility of implant supra-structure failure can be increased.