HCFFT 말뚝 현장지지력 실험

서재훈,김학군,김선희,유종호,윤순종 한국복합신소재구조학회 2017 복합신소재구조학회 학술발표회 Vol.2017 No.04

Conventional steel and concrete piles are widely applied in civil engineering industries with long time experience and many advantages. However, steel pipe piles, a sort of most common steel pile, are prone to losing their structural integrity over time due to corrosive and humid conditions. Moreover, concrete piles such as in-situ concrete piles and pretensioned spun high strength concrete (PHC) piles are subject to deterioration of their long-term structural durability. Therefore, Hybrid FRP-concrete composite pile (HCFFT) was developed. HCFFT is consisted of pultruded FRP (PFRP) unit module, filament winding FRP which is in the outside of mandrel composed of circular shaped assembly of PFRP unit modules, and concrete which is casted inside of the circular tube shaped hybrid FRP pile. Therefore, PFRP can increase the flexural load carrying capacity, while filament winding FRP and concrete filled inside can increase axial load carrying capacity. In this paper, field loading experiments were conducted to evaluate field bearing capacity of HCFFT pile with connection and HCFFT pile without connection.

지중매설 상수도용 GFRP관의 내압성능

서재훈,유종호,원용석,윤순종 한국복합신소재구조학회 2016 복합신소재구조학회논문집 Vol.7 No.4

In general, polyethylene (PE), polyvinyl chloride (PVC), and ductile cast iron pipes are widely used in the water supply pipeline system. However, they have some disadvantages such as reduced durability due to material degradation, defects in connections, breakage of pipelines, and difficulties in continuous maintenance. To mitigate such problems, recently, research on durable and outstanding corrosion resistant glass fiber reinforced polymer plastic (GFRP) pipe is being actively conducted. GFRP is classified into the flexible pipe and when soil pressure and live load act on buried GFRP pipe, the load acting on the pipe is transferred to the surrounding soil. So, it should review the structural behavior and interaction between buried pipe and its surrounding soil because pipe will support the load with the surrounding soil together at the same time. To apply GFRP pipe for the water supply pipeline system, the structural reliability of GFRP water supply pipe buried underground should be investigated by examining the mechanical properties of GFRP pipe as well as the soundness of the pipe under buried state. The field test of buried pipe is conducted and the results are analyzed and discussed.

지중매설 폴리에틸렌관의 구조적 거동과 설계

서재훈,이재호,유종호,김응호 한국복합신소재구조학회 2017 복합신소재구조학회논문집 Vol.8 No.3

In the sewer pipes, reinforced concrete pipes and concrete pipes are mostly used. However, it is difficult to ensure the long-term durability of the pipe due to the corrosion of the rebar which is used for the reinforcement of the concrete. Also, reinforced concrete pipes are difficult to secure watertightness due to deterioration and corrosion by hydrogen sulfide. In order to solve such problems, research on using sewer pipes made of plastic materials is being actively conducted. When soil pressure and live load act on the buried flexible pipe, the load acting on the pipe is transferred to the surrounding soil. So, the flexible pipe will support the load with the surrounding soil together. It is difficult to predict these behaviors theoretically and clearly. Therefore, the design equation for the buried flexible pipe is analyzed by adopting theoretically idealized assumptions and it is estimated through experimental studies that it is similar to the actual structural behavior. In this paper, the mechanical properties of the soil and the polyethylene pipe were considered in application of the method proposed in ASTM D 2412 to design the buried polyethylene pipe. Also, structural behavior of the pipe resisting external loads such as soil pressure was investigated to use a polyethylene pipe as the buried pipe and the long-term behavior of the polyethylene pipe was predicted by the compaction rate of surrounding backfill soil through the field test.

Three-Stage 스위치 네트워크의 Blocking 확률 및 통화처리능력 해석

서재훈,이강원,노승계,Seo, Jae-Hun,Lee, Kang-Won,Roh, Seong-Kye 한국전자통신연구원 1988 전자통신 Vol.10 No.4

전전자교환기에서 가장 많이 이용되고 있는 T-S-T three-stage 스위치 네트워크의 blocking 확률에 대한 대표적인 세가지 모형에 대해 살펴보고 스위치 네트워크의 구조 또는 통화로 탐색수에 따라 그 적용이 제한된 blocking 확률식에 대해 일반적으로 적용할 수 있는 확장된 표현식으로 유도하여 보았으며 각각에 대한 비교분석을 수행하였다. 또한 blocking 확률에 따른 three-stage 스위치 네트워크의 통화처리용량을 산출하는 방법을 설명하고 수리적인 예로서 위에서 제안된 blocking 확률모형들을 이용하여 TDX-1B 스위치 네트워크의 통화처리용량을 산출하여 보았다. 끝으로 T-S-T three-stage 스위치 네트워크에서의 blocking 확률모형들에 대한 전반적인 검토와 함께 blocking 확률을 줄일 수 있는 방법을 제안하였다.

지중매설 GFRP 상수관의 내압성능

서재훈,김선희,유종호,원용석,윤순종 한국복합신소재구조학회 2016 복합신소재구조학회 학술발표회 Vol.2016 No.04

In the water supply pipeline system polyethylene (PE), polyvinyl chloride (PVC), and ductile cast iron pipe are mostly used. However, they have some problems such as reduced durability due to material degradation, defects in connections, the pipelines breakage, and lack of continuous maintenance. Recently, research on durable and outstanding corrosion resistance glass fiber reinforced polymer plastic (GFRP) pipe is being actively conducted. GFRP is classified into the flexible pipe and when soil pressure and live load act on buried GFRP pipe, the load acting on the pipe is transferred to the surrounding soil. So, pipe will support the load with the surrounding soil. In this paper, to apply GFRP pipe for the water supply pipeline system, the structural reliability of GFRP water supply pipe buried underground should be investigated by examining the mechanical properties of GFRP pipe as well as the soundness of the pipe under buried state. The field test of buried pipe is conducted and the results are analyzed and discussed.

일차 양측성 구순열의 일단계 재건에 대한 증례보고

임석균,이기혁,김영균,김수관,이병준,여환호,서재훈 大韓顎顔面成形再建外科學會 1996 Maxillofacial Plastic Reconstructive Surgery Vol.18 No.3

Bilateral cleft lip reconstruction can be performed in one-or two-stages. The choice depends on the surgeon's proficiency and experience. However the type and severity of the cleft must be considered. Complete or incomplete symmetric, bilateral clefts in which the premaxilla is within the alveolar arch or slightly protruded can be successfully treated with simultaneous lip reconstruction on both sides. There are some advantages that one-stage lip reconstruction facilitates creation of a symmetric and balanced lip, retraction of protruding premaxilla and the parent's psychologic satisfaction. However, there are some disadvantages such as micrognathia of the upper jaw by severe scar formation and poor adaptation of flap margins by severe tension. The surgeon must be able to judge and exploit the advantages offered by one-stage approach. We present the case report of one-stage reconstruction of primary bilateral cleft lip with literature reviews.

Stevens-Johnson 증후군: 증례보고 및 문헌고찰

여환호,김영균,서재훈 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.1

The Stevens-Johnson syndrome is a severe form of erythema multiforme associated with multiple organ involvement that can result in severe mortality. There are many etiologic factors including drugs, infection, or stress ; but accurate pathogenesis is still obscure. Treatments are composed of the removal of possible etiologic factors, symptomatic and supportive treatment. We experienced a case of Stevens-Johnson syndrome with involvement of generalized skin, oral mucosa, and eye involvement. This patient was treated by symptomatic and preventive method including corticostervid, antihystamine, and opthalmic treatment.

치아회분말 및 치과용 연석고 혼합매식술에 관한 실험적 연구

조재오,김영균,여환호,양인석,서재훈 大韓顎顔面成形再建外科學會 1994 Maxillofacial Plastic Reconstructive Surgery Vol.16 No.2

This study was undertaken to determine whether the addition of calcium sulfate to toothash material (Toothash: plaster of paris=2: 1) would improve its stabilizing property without adversely affecting its osteoconduction. The radiographic and histologic examinations of bone response of this composite material was performed after 1-, 3-, 5-, 8-, and 12-week implantation in calvria of rats. No sign of extensive inflammatory response was detected. No movement could be observed with this composite material. Creeping substitution was observed in the surgical site. The direct union between toothash and growing bone after 12 weeks of implantation was observed in the defect margin. We could observe this composite implant material is resorbing slowly as time is over.

소프트웨어 보호를 위한 기술 분석

서재훈(JaeHoon Seo),유성민(SungMin Rue),박유경(YooKyung Park) 한국정보기술학회 2015 한국정보기술학회지 Vol.13 No.1

지식기반의 사회에서 소프트웨어 산업은 중요한 산업이다. 지식기반의 서비스가 중요해지면서 하드웨어보다는 소프트웨어가 중요해지게 되었다. 그리고 소프트웨어가 산업경쟁력의 원천이 되었다. 그렇기 때문에 소프트웨어 자산보호는 중요하며, 소프트웨어는 더 이상 무형이라고 해서 공짜가 아니다. 그러나 아직까지도 소프트웨어의 자산을 인식하지 않는 경우가 많으며 불법으로 도용하는 사례가 팽배하다. 비록 사회적으로 소프트웨어 산업을 보호하기 위해 법적인 제도가 마련되어 있지만, 소송과 같은 법적인 비용이 발생하기 때문에 별로 실용적이지 못하다. 따라서 소프트웨어 재산을 보호하기 위해서 다음과 같은 기술들이 있다: (1) 난독화, (2) 워터마킹, (3) 소프트웨어 임의조작방지. 비록 각각의 기술들을 적용하더라고 보완에 취약점이 있지만 세 기술들을 혼합하면 소프트웨어 보안에 크게 효과적이다.

특이한 악관절 강직증 : 진성 악관절 강직증과 상악골과 하악골 사이의 골성 유합

서재훈,조세인,여환호,이기혁,김영균 大韓顎顔面成形再建外科學會 1995 Maxillofacial Plastic Reconstructive Surgery Vol.17 No.2

TMJ ankylosis is classified with true and false type. A true ankylosis is defined as any condition that produces fibrous or bony adhesions between the articular surfaces of the temporomandibular joint. The main causes of true ankylosis are trauma or infection. A false ankylosis results from pathologic conditions outside the joint that limit mobility of the mandible such as myogenic disorders, coronoid impingement or rare direct bony fusion between maxilla and mandible. The treatment of choice of TMJ ankylosis is surgical intervention. We experienced the male patient with complete mouth opening limitation since 45 years before. This patient has true TMJ ankylosis and rare bony synostosis between maxilla and mandible in the right posterior region. We performed surgical intervention and had a favorable result.