• Tunnel and Underground Space
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• v.26 no.1
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• pp.32-45
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• 2016

For effective utilization of downtown area, many studies about underground have been performed around the world, and double-deck tunnel have being operated in USA, Europe and China, etc. (A86 East Duplex in France, M30 tunnel project in Spain, SR-99 in seattle, USA, Yangtze river tunnel in China) In Korea, the research about network type double-deck tunnel in deep underground space is in progress to solve the traffic jam and secure the ground space. In this study, a number of factors required for double-deck tunnel in deep underground are analyzed through the existing ventilation design outline and unique ventilation design factors for network type double-deck tunnel are established by reviewing design cases of overseas double-deck tunnel.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.2
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• pp.165-170
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• 2012

This paper contains the test method to obtain aerodynamic hinge moments acting on the control surface of air vehicle wing. During the flight, hinge moments make difference between actual control surface angle and control angle which is measured by sensor of actuator. The hinge moments can be obtained by using this difference. Static ground load test and calibration test were conducted to obtain torsional stiffness of control surface actuation system. This results are used to calculate hinge moments. In addition, the mechanical errors of actuation system such as slip angle of mounting point and backlash could be estimated. Using flight test results, this experimental measurement method of hinge moment acting on control surface is conducted. The results of this method are similar to those of numerical simulation method, and the validity of this method is proved.

• Journal of Broadcast Engineering
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• v.15 no.4
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• pp.555-562
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• 2010

After starting digital terrestrial broadcasting, there have been a number oftrials to provide new services like data broadcasting on a spare bandwidth of a DTV channel. Recently, the Push-VOD service, which provides A/V contents on that bandwidth, gets more attention and is being standardized as NRT(Non-Real-Time) by ATSC. However, it is highly probable that the contents transmitted in this way contain many errors due to the DTV receiving environment. Thus, in order to improve the reliability of transmission, the contents should be transmitted repeatedly several times, considering the unidirectional property of DTV terrestrial network. In this paper, we propose a method to calculate the optimal number of repetitions to transmit each contents in a way that minimizes the number of errors occured, when trying to transmit several contents to the receiver in a restricted time, using Markov-chain modeling and dynamic programming approach.

• Journal of Korean Medical classics
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• v.13 no.1
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• pp.253-268
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• 2000

1613년허준소간적(年許浚所刊的)${\ll}$동의보감(東醫寶鑑)${\gg}$불지시의사학종사자적연구과제(不只是醫史學從事者的硏究課題). 인위(因爲)${\ll}$동의보감(東醫寶鑑)${\gg}$병불시단순적의서(?不是單純的醫書), 이차서구유료도가내단사상급역학사상등철학사고지고(而此書具有了道家內丹思想及易學思想等哲學思考之故). ${\ll}$동의보감(東醫寶鑑)${\gg}$소출간적나시대수연성리학점굴료수위(所出刊的那時代雖然性理學占掘了首位), 단시차서소구적도교색채비임하의서갱농후(但是此書所具的道敎色彩比任何醫書更濃厚). 내경편적체계시피(內景篇的體系是被)${\ll}$황정경(黃庭經)${\gg}$영향적(影響的). 작위수련서(作爲修鍊書), ${\ll}$황정경(黃庭經)${\gg}$시도교주요경전지일是道敎主要經典之一). 비서인위인체즉시신적세계(比書認爲人體卽是神的世界), 인체적각기관우시저사신소주적안댁(人體的各器官又是這些神所住的安宅). 내경편이차(內景篇以此)${\ll}$황정경(黃庭經)${\gg}$위자爲資), 구성료기본체계급기주요내용(構成了基本體系及其主要內容). 우기시(尤其是), 내경편접수도가역학사상이설명천인상응(內景篇接受道家易學思想而說明天人相應). 즉(卽), 내경편접수(內景篇接受)${\ll}$참동계(參同契)${\gg}$주급(注及)${\ll}$회남자(淮南子)${\gg}$등도교문헌리소재적(等道敎文獻裏所載的)'발생론(發生論)', 인이음양오행적정기래해설만물여인지상응관계(因而陰陽五行的精氣來解說萬物與人之相應關係). 차정기계승위내단사상적정기신론(此精氣繼承爲內丹思想的精氣神論). 정여기(精與氣), 기여신(氣與神), 신여정시재우불단지호상접촉호상융화적관계상(神與精是在于不斷地互相接觸互相融化的關係上). 필자인위내경편이정기신론위주(筆者認爲內景篇以精氣神論爲主), 장의서인진료도교수련적경계(將醫書引進了道敎修鍊的境界). 단시(但是), 본론문불지간분석연구내경편소인적(本論文不至干分析硏究內景篇所引的)${\ll}$황제내경(黃帝內經)${\gg}$등의서포함적도교관(等醫書包含的道敎觀). 요시리해(要是理解)${\ll}$동의보감(東醫寶鑑)${\gg}$소인의서적사상기원급기내용(所引醫書的思想起源及其內容), 대연구내경편급(對硏究內景篇及)${\ll}$동의보감(東醫寶鑑)${\gg}$전편적철학성취유흔대적방조(全篇的哲學性就有?大的幇助). 차시필자요계속요연구적과제파료(此是筆者要繼續要硏究的課題擺了).

• Journal of Korean Society for Geospatial Information Science
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• v.8 no.1 s.15
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• pp.85-95
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• 2000

There is a recent emphasis on the need for updating and revision of existing digital maps as more digital maps are used and produced. Various type of data sources, such as photographs, ground surveyed data and satellite images, are used in the revision and the updating process. The process is very time consuming and costly, especially for small regional areas. This study, attempts to present an effective update/revision method using the as-built surveying drawings and the accuracy of the digital map which has been updated and revised using this method was also investigated. This study showed that by using as-built surveying drawings of scale 1/1,200 to update a digital map of scale 1/1,000, the resulting accuracy satisfied the requirements of the national digital map accuracy specification for the corresponding scale. The necessity of the existence of the necessary drawings and maps is a requirement of this process and it is also suggested that densification of local control points especially in the urban areas is necessary for producing accurate as-built surveying drawings. This would require the establishment of rules and regulations which would require constructions to perform as-built surveying, immediately after the construction has been completed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.2
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• pp.163-171
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• 2016

In order to detect the exact position of high-speed train, it is necessary to obtain location information from the transponder tag installed along the track. In this paper, we proposed parallel descrambling scheme for high-speed railway transponder system, which aims for reducing the processing time required to decode telegram. Since a telegram is stored in a tag after information bits are scrambled by an encoder, decoding procedure includes descrambling of received telegram to recover the original information bits. By analyzing the structure of the descrambling shift register circuit, we proposed a parallel descrambling scheme for fast decoding of telegram. By comparing the required number of clocks, it is shown that the proposed scheme significantly outperforms the original one.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.943-943
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• 2012

태백산맥의 중심부인 중앙산맥을 경계로 하여 동쪽에 위치하고 있는 영동지방은 서쪽으로 태백산맥이, 동쪽으로는 동해바다와 바로 인접해 있는 지리적인 특성으로 인해 지역적 특성이 매우 강하며, 이에 따라 국지적 기상현상이 계절적 변화와 함께 빈번히 발생하는 지역이다. 2002년 태풍 루사가 영동지방을 강타했을 때 영동지방의 대표도시인 강릉지방에서는 기록적인 폭우(일최다 강수량 870.5mm)가 내렸으며, 그 다음해인 2003년 매미 뿐 아니라 최근발생하고 있는 국지적인 호우로 인한 영동지방의 피해가 지속적으로 발생하고 있다. 이러한 상황에서도 수문학적 관점에서의 홍수유출 및 강우특성에 대한 분석 및 연구가 거의 전무한 실정이다. 이것은 대상지역인 영동지방 특히 삼척오십천 유역내의 강우 및 수위 관측소가 간헐적으로 분포되어 있으며, 강우 및 수위(유량)자료의 확보가 용이하지 않기 때문으로 사료된다. 본 연구에서는 동해 강릉 기상레이더(2010.5 동해기상레이더 교체 이전)의 레이더강우자료와 지상강우 및 수위(유량)자료를 활용하고, 집중형 모형에 비해 더 정확한 강우-유출 현상 모의가 가능한 것으로 분석되고 있는 분포형 모형(Vflo$^{TM}$)을 이용하여 분석하였다. 먼저 영동지역 중 첫번째로 삼척오십천유역에 대한 유출분석을 하였으며, 과거 큰 홍수피해를 준 태풍 루사 매미 및 최근의 호우사상을 대상으로 하였다. 본 논문에서 연구된 삼척오십천유역에 대한 유출특성 분석을 시작으로, 양양남대천 강릉남대천에 대한 유출특성에 대한 연구를 추가로 수행된다면, 영동지방의 국지적 기상현상(집중호우 및 태풍)으로 인한 홍수피해를 최소화 할 수 있는 방재측면에서의 홍수대응방안을 마련하는데 본 연구내용을 충분히 활용할 수 있을 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2016.05a
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• pp.168-168
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• 2016

도시화는 수문학적으로 산림이나 농경지와 같은 투수지역을 건물, 도로 등의 불투수 지역으로 변화시키는 것이며, 이로 인하여 홍수파의 도달시간이 줄어들고 첨두유량이 증가하는 등의 수문변화를 수반하게 된다. 도로나 건물 등이 대부분을 차지하고 있는 도시지역에서는 지표면이나 식생으로부터 대기 중으로 방출되는 증발산량이 농촌이나 산림지역보다 상대적으로 적으며, 강우시 토양중의 침투량과 지표면의 저류량도 도시지역에서는 매우 적게 나타난다. 도시화 전 후의 물순환특성을 평가하기 위해서는 도시 개발 전 후의 장단기 수문 관측 결과를 기초로 물순환계를 구성하는 인자간의 관계를 정량적으로 분석하고 물순환계 구성요소의 일부 변화가 다른 부분에 미치는 영향을 평가할 필요가 있다. 즉, 도시화가 물순환 구조 변동에 미치는 영향을 정량적으로 평가함으로써 유역 전체의 건전한 물순환 체계를 유지할 수 있는 대책 수립이 가능하다. 본 연구에서는 판교신도시 개발에 따른 유역에서의 홍수 및 유출특성 변화의 정량적 규명을 목적으로 두고 집중형 모형인 HEC-HMS모형과 물리적 기반의 준분포형 모형인 CAT을 이용하여 판교신도시 개발전의 정량적 물순환 특성을 평가하였다. 대상유역은 지방 2급 하천 탄천의 지류인 운중천, 금토천이 포함된 판교유역이며, 유역면적은 약 $25km^2$이다. 이 중 유역면적의 38 %에 해당하는 지역이 개발되었으며 개발된 지역은 하류부근에 위치한다. 강우자료는 지상 강우관측소인 수원 관측소의 지점강우 자료를 이용하였다. 도시 개발 전 단계에 해당하는 2006년, 2007년 호우사상 중 누적강우량 50 mm 이상인 호우사상을 추출하여 모의를 수행하였다. 유출 특성 분석을 위해 12개의 소유역과 5개의 하도로 구성하였으며 HEC-HMS의 손실량 산정방법으로는 SCS Curve Number법을 사용하였고, 단위도는 Clark 단위 도법을 적용하였다. CAT모형에서 침투는 Rainfall Excess방법, 하도추적은 Muskingum 방법을 적용하였다. 관측치와 모의치의 적합도 검증을 위해 RMSE (Root Mean Square Error), NSE (Nash Sutcliffe Efficiency), $R^2$값을 산정하여 비교 분석하였다.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.2
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• pp.84-89
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• 2021

Recently, shipyards are making many efforts to reduce the number of the mounted blocks by increasing the block size. This is to improve productivity and reduce related costs by minimizing block movement and shortening the building period. However, as the blocks become larger, the weight increases considerably. If the target block has a damage due to an unexpected accident during block lifting, it may seriously cause a problem of the reusability of the block. In this study, a large-sized block of the offshore structure weighing 480 tons was lifting with a total of seven sling belts, and one sling belt was broken while it was moving, resulting in a situation in which a part of the edge of the block collided with the ground. The aim of this paper is to verify the structural integrity of the block that directly collides with the ground in the form of free fall due to the sling breakage. Considering that the hook loads acting on several sling belts holding the block are redistributed when a sling belt is broken, the hook loads were recalculated at the angle just before the sling breakage. These loads were used to check the safety of the sling belts. In addition, FE analysis was performed by calculating the amount of impact from the free fall condition, obtaining the impact area by using Hertz's contact theory, and then applying the impact load to the area.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.3
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• pp.173-180
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• 2022

The operation and transportation environment for an unmanned aerial vehicle will be completely different from those for the conventional air and ground transportation. The requirement for a traffic management system for its safe operation has been emerging. Accordingly, investigation is being conducted to analyze the danger that unmanned aerial vehicle may encounter during the flight and to provide the countermeasure by the simulation. When the drones operate in an urban environment, they may be affected by the wind around the building. Thus it is essential to predict the influence of the gust and analyze the resulting risk. In this paper, a method for evaluating the safety for a flight mission under the gust is suggested. By using the precise 6-degree-of-freedom flight simulation that is capable of simulating the gust condition, possible deviation from the pre-planned flight path in terms of the attitude orientation will be predicted. A method of quantifying the probability of the flight mission failure will also be presented.