• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.76-76
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• 2015

토양수분은 생태수문학에서 식생과의 상호작용의 중요한 인자이자, 대기와의 상호작용으로 인한 총체적인 물 순환에 밀접한 관련이 있다. 수문학적으로는 증발, 침투, 지하수 함량, 토양 침식, 식생 분포 등을 지배하는 중요한 요소이고, 특히 시 공간적 분포특성은 강수 사상 후 토양으로의 침투 및 토양수분의 재분포, 증발산과 불포화대에서의 오염물의 이송을 예측하는데 매우 중요하다. 또한, '07년 하천법 개정으로 증발산량 및 토양수분량이 신규 수문조사 항목으로 추가되어, 토양수분 측정에 대한 필요성이 높아졌다. 따라서, 2008년 5월, K-water연구원에서는 현재 시험유역으로 운영하고 있는 용담시험유역에 토양수분관측망(6개 관측소)을 구축하였다. 토양수분계는 토양수분을 결정하는 가장 중요한 인자인 강우자료의 획득이 이루어지는 지점에 설치하여 정확도와 신뢰도를 높일 수 있도록 용담시험 유역 내 6개 우량관측소에 설치하였다. 하지만 장비의 노후화에 따른 자료 취득의 어려움으로 인하여 2013년 4월, 토양수분계를 전면 교체하였다. 토양수분계는 기존의 FDR 방식에서 EC 농도에 대한 영향이 가장 적고, 플럭스 타워에 위치한 토양수분계 센서와 동일한 TDR 방식의 센서로 장비를 전면 교체하였다. 센서 설치 장소 변경에 따른 TDR 센서의 검증과 그리고 흙의 종류, 입도, 다짐도, 온도 등에 의한 오차가 발생 여부를 판단하기 위하여 이에 대한 보정을 실시하였다. 원지반 시료채취를 통하여 토양수분량을 측정하였고, TDR 센서에 의해 측정된 토양수분량과 채취된 시료에서 측정된 토양수분량의 결과를 비교하였고, 각 지점별 토양구성비와 전기전도도 조건을 고려하여 각 토층별 계수적용을 달리하여 센서 보정을 실시하였다. 그 결과 기존 센서 제조사에서 제안한 방정식을 그대로 사용하는 것 보다는 센서 검증을 통하여 얻은 계수보정에 의한 토양수분 변환식을 사용하는 것이 정확한 현장 자료를 확보할 수 있고, 신뢰도 높은 자료를 얻을 수 있다고 판단된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.149-155
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• 2008

The road construction, as part of effort to ease the worsening traffic, has been underway throughout the nation, while the existing road has been increasingly losing its load carrying capacity due to such factors as heavy traffic and weathering. In the case of site, the soil type, plasticity index, and specific gravity were SC, 12.2%, and 2.66, respectively. The maximum dry density, optimum moisture content and modified CBR were $1.895g/cm^3$ (Modified Compaction D), 13.6%, and 16.2%, respectively. A correlation of coefficient expressed good interrelationship by 0.90 between the CBR estimated from a dynamic penetration index of dynamic cone penetrometer test and a deformation modulus converted from a dynamic deflection modulus obtained from a portable FWD test.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.166-175
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• 2009

An experimental study was carried out to estimate the flexural performance of steel fiberreinforced self-compacting concrete. Seven slabs with three different steel fiber-reinforced concretes were prepared to make beam specimens. After proper curing period, each slab was cut to five beams with a diamond saw. The beam specimen was tested with displacement control method to obtain load-deflection curve. As the results, the self-compacting concrete beam showed higher flexural strength, ductility and toughness index compared to the normal concrete beam. This means that steel fiber-reinforced self-compacting concrete can be used more widely in the field of architecture and civil engineering because of its self-compactability and good mechanical properties.

• Journal of the Korea institute for structural maintenance and inspection
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• v.23 no.5
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• pp.75-83
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• 2019

In order to fulfill the obligation to voluntarily reduce greenhouse gas emissions under the Paris Climate Agreement, the proportion of coal and nuclear power generation is reduced worldwide and national efforts are being made to spread renewable energy including solar power generation. Korea also intends to increase the proportion of renewable energy generation to 30~35% by 2040 by introducing laws and regulations. In addition, while the country is trying to apply solar power generation to sidewalks and roads, there is no research related to it in Korea. Therefore, as a precedent study to develop solar power generation roads, solar power generation concrete blocks applicable to sidewalks and plazas were developed and the applicability was evaluated by constructing them on the site. As a result of indoor experiment, compressive strength was measured by 25.5~35.7MPa and flexural strength was measured by 5.1~10.5MPa, which showed that all domestic standards were satisfied. However, the higher the unit cement amount, the lower the strength was measured according to the mixing of the broken fine aggregate. The absorption rate was 5.7%, which satisfied the domestic standard of 7% or less. As a result of the freeze-thawing test, the reduction rate of the compressive strength after 100 cycles was up to 6.3%. As a result of measuring the settlement amount after construction, the maximum of 2.498mm was measured and irregular settlement occurred in the overall area, which is because the resolution of the sand layer was poor during construction. Maintenance techniques of sidewalk concrete block and solar panel need to be established more efficiently through long-term operation in the further.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.733-739
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• 2009

Recently it is being increased rapidly to install magnetic marker and RFID tag on the underground utility lines before backfilling to ensure effective it's management. However, due to changes an attitude and damages of sensors. By pressure and vibration during soil compacting, detecting rate is significantly reduced as well as it allows to use only one line of various pipes since it has an unique frequency. Also it is required too long time to reach to target point with an non-accurate navigational GPS receiver and hard to update existing data base with a manual input of new data in the field. To improve these problems, the researcher developed the field management system that apply with ball typed self-levelling marker which is free from the changes of attitude for sensors during compaction as well as has various radio frequency applicable to many kind of pipes and ensure fast positioning to target point using an incorporated system with PDA based DGPS receiver which allows loading a field GIS software and RFID detector. Further, it provides with viewing all of RFID data on the DGPS receiver screen directly and also input new data to existing data base in the field automatically.

• Journal of Korean Society of Archives and Records Management
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• v.2 no.2
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• pp.1-38
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• 2002

This study examines the status quo of Korean archives and records management from the Governmental as well as professional activities for the development of the field in relation to the new legislation on records management. Among many concerns, this study primarily explores the following four perspectives: 1) the Government Archives and Records Services; 2) the Korean Association of Archives; 3) the Korean Society of Archives and Records Management; 4) the Journal of Korean Society of Archives and Records Management. One of the primary tasks of the is to build the special depository within which the Presidential Library should be located. As a result, the position of the GARS can be elevated and directed by an official at the level of vice-minister right under a president as a governmental representative of managing the public records. In this manner, GARS can sustain its independency and take custody of public records across government agencies. made efforts in regard to the preservation of paper records, the preservation of digital resources in new media formats, facilities and equipments, education of archivists and continuing, training of practitioners, and policy-making of records preservation. For further development, academia and corporate should cooperate continuously to face with the current problems. has held three international conferences to date. The topics of conferences include respectively: 1) records management and archival education of Korea, Japan, and China; 2) knowledge management and metadata for the fulfillment of archives and information science; and 3) electronic records management and preservation with the understanding of ongoing archival research in the States, Europe, and Asia. The Society continues to play a leading role in both of theory and practice for the development of archival science in Korea. It should also suggest an educational model of archival curricula that fits into the Korean context. The Journals of Records Management & Archives Society of Korea have been published on the six major topics to date. Findings suggest that "Special Archives" on regional or topical collections are desirable because it can house subject holdings on specialty or particular figures in that region. In addition, archival education at the undergraduate level is more desirable for Korean situations where practitioners are strongly needed and professionals with master degrees go to manager positions. Departments of Library and Information Science in universities, therefore, are needed to open archival science major or track at the undergraduate level in order to meet current market demands. The qualification of professional archivists should be moderate as well.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.219-224
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• 2007

As use of construction equipment has been increasing continuingly, the proportion of equipment expense to the total construction cost has become higher. However, there is a difference between the equipment expenses section in 'Poom-Sam' and practical data, because 'Poom-sam' does not consider non-working days due to weather conditions, legal holidays and management conditions. Therefore, 'Poom-Sam' does not present a reasonable standard for estimating construction equipment expenses. In this study, to estimate realistic construction equipment operating hours, firstly, construction equipment was classified according to work, and weather conditions, in which each work could not be executed, were established. Then, weather data on Seoul and Busan(2004${\sim}$2006) and legal holidays were analyzed to suggest annual standard operating hours. The annual standard operating hours of earthmoving & excavating, compaction, and drilling equipment was estimated to be 1,430 hours, and lifting equipment, concrete paving equipment, asphalt paving equipment, concrete equipment, and crushing & conveying equipment were estimated to be 2,124 hours, l,156hours, 1,188hours, 1,688hours, and 2,152hours respectively.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.603-610
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• 2017

Various type of pavement deterioration such as crack, bumpy, pothole is rapidly increasing according to the accelerated environmental changes like heavy rainfall, frequent snowing, difference temperature, etc. Accident related to pothole that cause fatal traffic accidents has been increased more than five times over the next five years starting from 2008. As direct or indirect damage by pothole which caused injuries and car damages increases every year, quicker and more efficient management measures are necessary. This study presents the algorithm for materials quantity take-off. The algorithm was suggested by correlation in pothole size and area. Suggested algorithm were confirmed the validity through the 15 field survey in capital area. According to the results of survey, usually the residual materials at which 5~7 kg was generated decreased to 1~2 kg. It showed that automatic pothole detection system is expected not only to reduce materials and resources, but also to contribute to quality improvements of pavement through more accurate material take-off from the situation of constructing rely on their own judgement.

• Journal of Biosystems Engineering
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• v.34 no.6
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• pp.397-403
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• 2009

This study was carried out to investigate the present status of subsoil compaction, and subsoil compaction management in orchard as a basic study for developing a self-propelled explosive subsoiler. Subsoil compaction was evaluated using the soil penetration resistance. Soil cone index was measured using the DIK 5520 type cone penetrometer in several fruit farms such as apple, pear, peach and grapes during growing seasons of these fruit in Jecheon, Gamgok, Choongju, Cheonan and Hwasung areas. Most of the subsoil managing machinery were either explosive type or digging type attached to the tractor or power tiller and turning radius of this machine was more than 3-5 m. Many of the farmers wanted to use the subsoiler which can put lime into soil and rupture soil at the same time. For most of the orchard fields, soil penetration resistance in vehicle traffic area was increased quickly and reached about 1.0 MPa in 5 cm soil depth. As the soil depth increased to 15-20 cm, cone penetration resistance reached about 2.0-2.5 MPa which restricted root growth seriously. Thus it was concluded that one of the main reason for increasing the soil compaction in orchard fields is agricultural vehicle traffic. In the vicinity of fruit trees, compaction is not so serious compared to that of the vehicle traffic area, but as the soil depth increased to 20-25 cm, in most of the orchard fields soil penetration resistance reached about 2.0-2.5 MPa which is the root growth-limiting value. Considering the rooting depth of fruit trees which ranged 30-60 cm for apple, pear and peach, and 20-30 cm for grape, it is necessary to loosen the subosoil and improve the subsoil conditions using subsoiler.

• Geotechnical Engineering
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• v.12 no.5
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• pp.103-116
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• 1996

Man-made vibrations from traffic and construction activities are important because they may cause damage to structures. The current literature provides that damages in the urban areas were not caused by direct transmission of vibration, but rather through subsequent settlement caused by soil densification. In this paper. prediction technique of ground borne vibration induced settlement was introduced on the basis of case studies. In situ application technique of the settlement prediction model developed in laboratary was described, and the predicted settlement was compared with the measured settlement from case studies. The settlement from case studies hlatched well with the settlement calculated from the model. The parametric studies of settlement in typical urban site conditions were performed to determine the sensitive parameters and to develop reliable vibration monitoring and interpretation schemes. These demonstrated the potential usefulness of the model for the evaluation and prediction of the vibration induced in-situ settlement of sands.