• 한국수자원학회논문집
• /
• 제57권5호
• /
• pp.311-320
• /
• 2024

최근 국내에서는 이상기후로 인해 가뭄의 빈도 및 심도가 증가하고 있으며 장기간의 가뭄으로 인한 저수지의 저수량 감소로 전국적인 가뭄 피해가 발생하였다. 가뭄 기간 동안의 피해를 최소화하기 위해 관측자료를 이용한 최적의 저수지 운영 방법을 제안하는 다양한 연구가 수행되었지만, 실측 자료만을 활용할 경우 과거 가뭄 사상에 대해서만 분석이 가능하기 때문에 미래에 발생할 수 있는 극심한 가뭄을 예측하고 분석하기 위한 기술이 필요한 실정이다. 본 연구에서는 최근 가뭄피해가 발생한 섬진강 유역에 위치한 섬진강댐을 대상으로 최소유입량 예측 기법을 제시하였다. 수문 분석 모형인 Stochastic Analysis Modeling and Simulation (SAMS) 2007을 이용하여 섬진강댐의 관측자료와 통계적 특성이 유사한 동일한 길이의 유입량을 다수 발생시키고, 저수지 모의운영에 따른 보장공급량 산정 결과를 활용하여 최소유입량을 예측하였다. 본 연구에서는 최소유입량을 대상 저수지의 관측자료와 동일한 기간을 갖는 다수의 발생유입량 중 보장공급량을 기준으로 95%는 이보다 작지 않은 값을 갖는 유입량으로 정의하였다. Case별 저수지 모의운영 분석 결과 섬진강댐 최소유입량의 보장공급량은 관측자료의 보장공급량인 10.51 m³/s 대비 평균 1.07 m³/s 낮게 분석되었다. 본 연구에서 산정한 최소유입량은 가뭄 시 저수지 운영 기준을 마련하는데 활용할 수 있을 것으로 판단되며 최소유입량을 활용하여 댐 연계운영, 추가 확보 가능한 용수공급량 등을 검토할 수 있다. 이는 가뭄 시 용수공급 안정성 확보 및 하류 물부족 문제 해소 등을 위한 대안 마련 시 활용될 수 있을 것으로 기대된다.

• 한국안광학회지
• /
• 제9권2호
• /
• pp.397-415
• /
• 2004

본 연구는 시력보정용 안경렌즈와 관련된 KS규격과 ISO, JIS 및 ANSI 규격을 비교하고 시중에 유통되고 있는 안경렌즈를 각 규격에 합당한지 여부를 판단하여 현 KS규격의 문제점과 개선책을 검토하였다. KS규격은 ISO규격을 대응으로 하고 있고 단초점과 다초점 및 누진을 통합한 규격인 ANSI 규격의 구조를 가지나 용어의 정의와 누진렌즈에 관한 내용이 없다. 검사항목은 ISO규격에 준하고 있지만 ANSI 규격과 비교시 광학적 요건이나 기하학적 요건이 없는 사항도 있었다. 유통되고 있는 안경렌즈의 주요 항목 평가에서 굴절력, 렌즈의 치수, 외관 및 품질 등에 관한 것은 명시된 것과 큰 차이점은 없었으나 렌즈의 두께나 베이스 커브 및 가시광선 또는 자외선의 투과율에 관한 기준이 없고 제품 간의 차이가 있어 이에 대한 기준이 필요하다.

• Journal of the Korean Wood Science and Technology
• /
• 제48권3호
• /
• pp.393-404
• /
• 2020

아세틸화 처리한 라디에타소나무 섬유를 사용하여 제조한 MDF의 수분에 대한 재질 특성을 조사하고 KS F 3200의 섬유판 품질기준과 비교하였다. 아세틸화 처리 MDF는 품질 기준보다 매우 낮은 함수율과 수분 흡수성 및 두께 팽창율을 보여 우수한 치수안정성을 기대할 수 있다. 아세틸화 처리 MDF의 습윤 시 휨강도는 기건 상태 휨강도의 약 70% 이상에 달해 품질 기준에 적합하였다. 아세틸화 MDF의 습윤 시 박리강도가 품질기준의 기건 상태의 최저 박리강도보다 높은 결과를 보여 내수성이 매우 우수하였다. 아세틸화 MDF의 물방울 접촉각은 무처리 MDF에 비하여 커서 낮은 습윤성에 의한 내수성 향상에 기여하는 것으로 판단된다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.5-21
• /
• 2006

Traditional standards and specifications for concrete have largely been prescriptive, (or prescription-based), and can sometimes hinder innovation and in particular the use of more environmentally friendly concretes by requiring minimum cement contents and SCM replacement levels. In December 2004, the Canadian CSA A23.1-04 standard was issued which made provisions (a) for high-volume SCM concretes, (b) added new performance requirements for concrete, and (c) clearly outlined the requirements and responsibilities for use in performance-based concrete specifications. Also, in December 2003, the CSA A3000 Hydraulic Cement standard was revised. It (a) reclassified the types of cements based on performance requirements, with both Portland and blended cements meeting the same physical requirements, (b) allows the use of performance testing for assessing sulphate resistance of cementitious materials combinations, (c) includes an Annex D, which allows performance testing of new or non-traditional supplementary cementing materials. From a review of international concrete standards, it was found that one of the main concerns with performance specifications has been the lack of tests, or lack of confidence in existing tests, for judging all relevant performance concerns. Of currently used or available test methods for both fresh, hardened physical, and durability properties, it was found that although there may be no ideal testing solutions, there are a number of practical and useful tests available. Some of these were adopted in CSA A23.1-04, and it is likely that new performance tests will be added in future revisions. Other concerns with performance standards are the different perspectives on the point of testing for performance. Some concrete suppliers may prefer processes for both pre-qualifying the plant, and specific mixtures, followed only with testing only 'end-of-chute' fresh properties on-site. However, owners want to know the in-place performance of the concrete, especially with high-volume SCM concretes where placing and curing are important. Also, the contractor must be aware of, and share the responsibility for handling, constructability, curing, and scheduling issues that influence the in-place concrete properties.

• 대한전자공학회논문지TC
• /
• 제41권1호
• /
• pp.73-82
• /
• 2004

GFR 서비스는 UBR의 단순성을 유지하면서 최소 전송율 보장, 잉여 대역의 공평한 할당 및 효율적인 링크 대역의 사용을 보장해야 한다. ATM에서 TCP 트래픽에 대응해서 만들어진 이러한 GFR 서비스 클래스의 효율적인 관리를 위해서는 ATM 스위치에서의 버퍼 관리가 필요하다. 제안된 버퍼 관리 알고리즘은 단일 FIFO에서 per-VC accounting 방식을 사용하며 GFR.1 및 GFR.2 모두를 수용할 수 있는 버퍼 관리 알고리즘이다. 제안된 알고리즘은 GFR.1 및 GFR.2를 차별적으로 다루기 위해서 CLP=0인 셀 수 및 CLP=1인 셀 수를 이용하여 버퍼 관리를 함으로써 GFR.1 VC들과 GFR.2 VC들에게 공평하게 잉여대역을 할당하여 사용함을 볼 수 있었으며, 전체 공평성 관점에서도 기존 알고리즘보다 우수한 성능을 보여주었다.

• 교육시설
• /
• 제9권1호
• /
• pp.15-26
• /
• 2002

According to seventh curriculum, new types of school design have been developed recently. However there are hardly any data of national status about plan and area organization, types and number of rooms of those. On this background, the purpose of this study is to provide fundamental resources for architectural designing and planning of high schools and to recognize national status of plan organizations of high schools through collecting 53 school's standard design drawings(arrangement, plan drawing) which city, province education office drafted for 4 years(from 1997 to 2000) and analyzing them into plan types, building area and type, number and area of rooms. The results of this study are as follows: 1. The range of class number of designed 53 high schools varies from 24 to 36 and 36-class-schools are 47.2% of all. Average number of class is 34.1. As a result we can find out large scale schools are mainly designed. 2. Among 53 schools, 21 schools have the department system but few of them equipped sufficient rooms and their features are very manifold. After recognizing utilization status of each schools, the standards of room type, number and plan organization should be proposed. In terms of plan type for fluent level based transferring class, most of schools are not apt. 3. In the status of type and number of rooms related to class number, range is very wide. So simplification is necessary. 4. The variations of building area, area per a class and area per a student are very large so that standard of adequate area should be established. 5. That every school which has different plan organization from conventional schools exceeds ministry of education's minimum area standards shows those standards cannot cover the diverse plan design of school. So more adequate standards should be proposed. 6. Area and number of Teacher's research room and Home Base are also very manifold from school to school. They are also considered to be simplified immediately.

• 대한화학회지
• /
• 제36권2호
• /
• pp.273-281
• /
• 1992

원자흡수분광법을 위한 글로우방전 분광 장치를 sputtering된 시료원자가 기저상태의 원자가 최대이며 여기 상태의 원자가 최소가 되는 지역을 측정하도록 설계 개발하였다. 빠른 속도의 가스 jet는 방전의 육안 및 전기적 변화 뿐만 아니라 시료표면의 변화에서 처럼 시료가 원자화되는 양을 현저히 증가시킨다. 가스 jet는 원자흡수분광법으로 시료를 직접할 수 있는 가능성을 보여주었다. 감도와 재현성에 영향을 끼치는 여러 가지 요인들에 관하여 연구하였다.

• 농업과학연구
• /
• 제43권3호
• /
• pp.360-368
• /
• 2016

A more efficient use of nutrients can benefit both farmers and water quality. To propose an establishment scheme for official standards for liquid fertilizer from swine manure slurry, we evaluated previous and present data related to swine manure as well as analyzed 101 swine manure samples collected from 28 public livestock recycling centers throughout the nation. From these investigations, we found that the official standards for byproduct fertilizers set by the Rural Development Administration (RDA), especially for a liquid swine manure fertilizer, should be revised due to nutrient content requirements having to meet at least 0.3% content for the sum of nitrogen, phosphorus, and potassium. Otherwise, most of the swine manure cannot be utilized as a liquid fertilizer because the result of the 101 samples' analysis showed fewer than 28% of them met the minimum standard of ${\geq}0.3%$ content for the sum of nitrogen, phosphorus, and potassium, while the contents of heavy metals as indicators of toxicity met the standard requirements. Therefore, it is suggested that official standards for byproduct fertilizers set by RDA should be revised as follows: no limit for nutrient contents and addition of chloride as homogeneity. Also, NaCl should be changed to Na because NaCl cannot be analyzed by instrument.

• 교육시설 논문지
• /
• 제18권4호
• /
• pp.57-67
• /
• 2011

In this study, it did comparative analysis on the arrangement, construction and size of rooms applied in the early design stage at the time of prize-winning with the changed ground plans in the final design of those prize-winning works in design contests and BTL hold since 2007 for middle and high schools in Gyeonggi, Daejeon, Chungcheong regions. Through the analysis, this study intends to present those matters to be changed in the facilities standards of each local education office so that it can be referred to the assessment of spatial construction and proper size being planned in the future for middle and high schools and reflected flexibly in consideration of various educational conditions and characteristics of schools by regions. Furthermore, it has the objective to play a part for the establishment of much better environment of educational facilities by provision of reference materials to those matters being changed into proper ones not into the minimum ones of the school facilities standards as the national level. For case analysis, it analyzed various rooms classified by necessary spaces. Since names of rooms and spatial constructions to constitute facilities are different from each local education office and also the analysis by each room has some limitation in the changes and improvement of rooms for a wide range, it proceeded with detailed classifications of school building facilities by each necessary space.

• 농촌계획
• /
• 제29권4호
• /
• pp.13-26
• /
• 2023

Recently, South Korea has prepared laws and systems to systematically manage rural spaces in response to the era of population decline and is making various efforts to promote related policies. However, various basic studies that can support this are still insufficient. In particular, in this study, the functions and roles of each settlement class were established along with the classification of the sedentary classes in rural areas, and the classification system for rural living services was established, and the hierarchy by functional facilities and the minimum standards for vulnerable areas (accessibility) were established. Specifically, in this study, the settlement class was divided into 4 classes of "central area - midpoint area - small point area - hinterland", and each function and role was presented, and the rural living service classification system was finally reestablished as 10 sectors and 31 functional facilities. In addition, the hierarchy and accessibility standards of rural living service functional facilities was set within 5 to 15 minutes for 'lower and basic services', within 10 to 20 minutes for 'medium and basic services', within 15 to 30 minutes for 'intermediate and complex services', within 20 to 60 minutes for 'high car/complex service' and within 10 minutes for 'urgent service'.