직접전단시험(直接剪斷試驗)에 의한 화강토(花崗土)의 전단특성(剪斷特性)에 관(關)한 연구(硏究)

이달원,강예묵,조성섭,Lee, Dal Won,Kang, Yea Mook,Cho, Seong Seup 충남대학교 농업과학연구소 1986 Korean Journal of Agricultural Science Vol.13 No.2

공학적(工學的) 성질(性質)이 복잡(複雜)한 화강암질풍화토(花崗岩質風化土)를 함수비(含水比) 및 밀도(密度)와 변형속도(變形速度) 등(等)을 달리하여 수침시(水浸時)와 비수침시(非水浸時)에 대한 전단시험(剪斷試驗)을 하고, 이들간의 상호관계(相互關係)가 전단강도(剪斷强度)에 미치는 영향(影響)을 비교(比較) 분석(分析)하여 다음과 같은 결론(結論)을 얻었다. 1. 함수비(含水比)가 증가(增加)하면 전단강도(剪斷强度)는 감소(減少)하여, A 시료(試料)는 함수비(含水比) 5~10%에서, B 시료(試料)는 함수비(含水比) 15~20%에서, 강도(强度)의 감소율(減少率)이 크게 나타났다. 2. 점착력(粘着力)과 내부마찰각(內部摩擦角)은 함수비(含水比)가 증가(增加)함에 따라서 감소(減少)하고 건조밀도(乾燥密度)가 증가(增加)함에 따라 증가(增加)하였다. 3. 수직응력(垂直應力)이 증가(增加)함에 따라 전단강도(剪斷强度)는 증가(增加)하였고, 체적변화(體積變化)는 대체(大體)로 감소(減少)(압축(壓縮))하는 경향(傾向)을 나타내었다. 또 변형속도(變形速度)가 증가(增加)할수록 전단강도(剪斷强度)는 대체(大體)로 증가(增加)하는 경향(傾向)을 나타내었다. 4. A시료(試料)는 밀도(密度)가 증가(增加)할수록 진행성파괴형태(進行性破壞形態)를 보이고 체적(體積)은 감소(減少)(압축(壓縮))하였으며, B시료(試料)는 초기(初期)에 파괴(破壞)되고 체적(體積)은 증가(增加)(팽창(膨脹))하는 경향(傾向)을 나타내었다. 5. 수침시(水浸時)의 전단강도(剪斷强度)는 비수침시(非水浸時)에 비(比)해서 감소(減少)하였고, 관계식(關係式)은 A시료(試料)에서는 ${\tau}_f=0.1009+1.026{{\tau}_f}^*$이고, B시료(試料)에서는 ${\tau}_f=0.1586+0.8005{{\tau}_f}^*$로 나타낼 수 있었다. 6. 내부마찰각(內部摩擦角)은 직접전단시험(直接剪斷試驗)에서 더 크게 나타났고, 유효응력경로(有效應力經路)는 거의 유사(類似)하게 나타났다. This paper describes the observed behavior in the direct shear test on decomposed granite soil having the complicate engineering properties at various different levels of factors. The objectives of this study were to investigate the characteristics of the decomposed granite soil under controlled various moisture content, dry density, strain rate and soaking which give influence to the shear strength. The results were summarized as follows; 1. The shear strength was decreased remarkably with the increasing of moisture contents of A and B soil were 5-10% and 15-20% respectively. 2. Cohesion and angle of internal friction were decreased with the increasing of moisture content and increased with the increasing of dry density. 3. The shear strength was increased with the increasing of normal stress and volume change was decreased on the whole. The shear strength was generally increased with the increasing of the strain rate. 4. As dry density increases, A-soil shows the progressive failure and the decrease of volume change while B-soil shows the initial failure and the increase of volume change. 5. The relationships between the soaked and unsoaked specimens were as follows ; ${\tau}_f=0.1009+1.026{{\tau}_f}^*$ (A-soil), ${\tau}_f=0.1586+0.8005{{\tau}_f}^*$ (B-soil) 6. Angle of internal friction of the direct shear test shows larger value than that of the triaxial compression test. All effective stress path was nearly similar.

현장계측치로부터 역산한 압축지수와 압밀계수의 평가 방법

이달원,임성훈,김지문 충남대학교 농업과학연구소 2000 농업과학연구 Vol.27 No.1

본 연구는 연약지반의 심도가 깊으면서 압밀침 하량이 큰 지역에서 연직드레인 공법에 의하여 개량한 지반의 침하거동을 파악하고, 현장계측결과를 기초로 기존의 최종침하량의 예측방법과 현장계측치로부터 역산한 압축지수와 압밀계수의 범위를 실내시험과 비교분석 한 것으로 본 연구대상지역에서 얻은 결과를 요약하면 다음과 같다. 1. 최종침하량 예측방법에 의하여 구한 최종예상침하량은 쌍곡선 방법이 가장 크고, Asaoka 방법과 Curve fitting 방법은 유사하게 나타났으며, 타입간격이 좁을 경우에는 교란영향을 고려한 설계가 검토되어야 할 것으로 판단된다. 2. 실측압밀도(U_(m))와 설계압밀도(U_(t))와의 관계는 쌍곡선 방법에서 U_(m)=(0.88~l.03)U_(t) 으로 약간 작게 나타났고, Asaoka 방법은 U_(m)=(1.07~1.20)U_(t), Curve fitting 방법은 U_(m)=(1.13~l.17)U_(t)으로 유사하게 나타났다. 3. 실내압축지수(V_(cc_(lab)))와 현장압축지수 (Cc_(Field))와의 관계는 쌍곡선 방법에서는 Cc_(Field)=(1.26~1.45) V_(cc_(lab)), Asaoka 방법에서는 Cc_(Field)=(1.08~1.15) V_(cc_(lab)). Curve fitting 방법에서는 Cc_(Field)=(1.04~l.21) V_(cc_(lab))의 범위로 쌍곡선방법에서는 약간 크게 나타났고, Asaoka와 Curve fitting 방법은 거의 동일한 값을 나타냈다. 4. 현장계측치로부터 역산한 현장압밀계수(C_(h))와 실내시험에서 구한 수직압밀계수(C_(v))와의 비는 (C_(h)/C_(L)) 쌍곡선방법에서는 0.7~0.9, Asaoka방법에서는 0.9~l.5, Curve fitting 방법에서는 2.4~3.0의 범위로 나타났다. 5. 현장압밀계수는 방치기간이 경과함에 따라서 점차로 감소하는 경향을 나타내므로 압밀이 완료되었을 때에 최종침하량 예측방법에 의하여 재분석한 후 정확한 압밀계수를 산정하는 것이 합리적 이라고 판단된다. A large scale field test of prefabricated vertical drains is performed to analyze the effect of parameters of the very soft clay at a test site. Compression index and the coefficient of horizontal consolidation obtained by back-analysis from the settlement data were compared with those obtained by means of laboratory tests. The Hyperbolic, Asaoka's and The Curve fitting methods are used to estimate final settlements and coefficients of consolidation. 1. Final settlement predicted with the Hyperbolic method was the largest, and the settlements predicted with the Asaoka's and the Curve fitting methods were nearly the same range, and it was concluded that smear effect has to be considered on design in the case that spacing of drains is small 2. The relationships of the measured consolidation ratio(U_(m)) and the designed consolidation ratio(U_(t)) were showed as U_(m)=(1.13~l.17)U_(t), U_(m)=(1.07~l.20)U_(t), U_(m)=(1.13~l.17)U_(t) on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. The relations on the Asaoka's and the Curve fitting methods were nearly the same range. 3. The relationships of the field compression index(C_(cfield)) and virgin compression Index(V_(cclab).) were showed as C_(cfield)=(1.26~l.45)V_(cclab). C_(cfield)=(1.08~l.15)V_(cclab). C_(cfield)=(1.04~l.21)V_(cclab). on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. 4. The ratio (C_(h)/C_(v)) of the coefficient of vertical consolidation and the coefficient of horizontal consolidation that is obtained by back-analysis from the settlement data was C_(h)=(0.7~0.9)C_(v). C_(h)=(0.9~l.5)C_(v). C_(h)=(2.4~3.0)C_(v) on the Hyperbolic, Asaoka's and the Curve fitting methods, respectively. 5. It was concluded that the exact consolidation coefficient must be determined after the final settlement is predicted again when the consolidation is finished, because the field consolidation coefficient is decreased as the time allowed to be alone is increased

MIPv6에서 권한위임을 이용한 위치수정 방안

이달원,이명훈,황일선,정회경,조인준 한국정보통신학회 2004 한국정보통신학회논문지 Vol.8 No.6

IETF mip6 WG에서 MN의 위치를 나타내는 '바인딩정보'를 안전하게 CN에게 송신하여 위치정보를 수정하는 RR프로토콜이 2004년 6월에 RFC 3775로 표준화되었다. 표준화된 RR프로토콜은 시작주체 및 시점이 MN에 의해 이루어짐으로서 위치정보수정 지연에 따른 홈네트워크의 부담 및 통신지연 증가를 문제점으로 지적할 수 있다. 또한 보안측면에서 CN과 HA간에 위치하는 공격자에게 취약성을 내포하고 있다. 본 논문에서는 MN의 위치정보 수정권한을 HA로 위임시키는 새로운 위치정보수정 방안을 제안한다. 즉, MN의 위치정보를 HA에 등록시 MN의 개인키로 서명된 위치정보 인증서를 사용하여 등록하고 이 인증서를 HA가 CN에 MN의 위치정보 수정시 사용하는 방안이다. 이를 통해서 위치정보수정에 소요되는 시간을 단축하고 교환되는 메시지 수를 감소시켜 통신부담을 경감시키는 효과를 얻을 수 있다. 또한 CN과 HA간에 위치한 공격자에 대한 보안 취약성을 제거하였다. The RR protocole, proposed in IETF mip6 WG and standardized by RFC 3775 at lune 2004, send a message 'Binding Update' that express MN's location information to CN safety and update location information. Standard RR protocole has some problems with initiating the protocol by the MN; it causes to increases in communication load in the home network, to increases communication delay between MN and CN. Also, is connoting vulnerability to against attacker who are on the path between CN and HA in security aspect. This paper proposes doing to delegate MN's location information update rights by HA new location information update method. That is, When update MN's location information to HA, Using MN's private key signed location information certificate use and this certificate using method that HA uses MN's location information at update to CN be. It decreases the route optimization overhead by reducing the number of messages as well as the using location information update time. Also, remove security weakness about against attacker who are on the path between CN and HA.

제척(除斥)$\cdot$기피(忌避)$\cdot$회피(回避)

이달원 한국제품안전협회 2003 제품안전 Vol.113 No.-

한국 근대사에 있어서 체육에 관한 연구(Ⅱ) : 해방 직후 과도기의 학교체육을 중심으로

이달원,배정행 啓明專門大學 産業開發硏究所 2002 啓明硏究論叢 Vol.20 No.1

본 연구는 해방 직후 과도기 교육과정 속의 체육을 살펴보고자 하였다. 해방 직후 우리나라는 혼란 속에서도 우리 민족선각자들의 민족주의 교육열망과 민주주의에 의한 미군정의 서구적 의식에 의하여 체육이 표면적 발전을 이를 수 있었다. 그러나 당시의 불안정한 시대적 상황과 첨예한 이념의 대치 속에서 그 가치는 혼미를 거듭하였던 것이다. 따라서 현대 체육교육이 바로 서기 위해서는 교육에 대한 완벽한 준비와 교육 본연의 의미를 희석시키는 모든 상황과는 단절할 수 있는 교육의 독립성을 유지하여야 한다는 것이다. This research focuses on physical education of school during the time of transition after liberation. Enthusiasm of old scholar and influence from USA educational pattern, Physical education acquired superficial development. However. Value of physical education under social disorder and ideology conflict were not fully assessed, Preparation and Isolation of education itself are critical to realize true meaning or thought of physical education.

정적하중 상태에서 포화된 실트질 모래의 액상화 거동

이달원,Lee Dal-Won 한국농공학회 2006 한국농공학회논문집 Vol.48 No.4

This study was carried out to investigate the liquefaction behaviour of saturated silty sand under monotonic loading conditions. The undrained soil tests were conducted using a modified triaxial cell and specimens were prepared using the moisture tamping method. Undrained triaxial compression tests were performed at different confining pressures, void ratios and overconsolidation ratios and the samples were sheared to axial strains of about 20% to obtain monotonic loading conditions. It is shown that increasing confining pressures, void ratios and overconsoildation ratios increases the deviator stress, but it has no effect on increasing the dilatant tendencies. It is shown that complete static liquefaction was observed regardless of increases in the confining pressure, void ratio and overconsolidation ratio. Therefore, the confining pressure, void ratio and overconsoildation ratio does not provide significant effects on the liquefaction resistance of the silty sand. The presence of fines in the soil was shown to greatly increase the potential for static liquefaction and creates a particle structure with high compressibility for all cases.

한국 근대사에 있어서 체육의 역할(Ⅰ) : 학교체육을 중심으로 with school physical education as the central figure

이달원,조연철 啓明大學校 生活科學硏究所 1997 科學論集 Vol.23 No.-

This thesis treated with the role of school physical education in korean modern history. The modern schools been established by pioneer or christian missionary since the end of seventeenth century have taken advantage of physical education for the sake of the retrieval of national prestige and wealthy country and a powerful army and have developed the racial physical education. These schools of various kinds have set the goal at knowledge, virtue and physical education of education and especially have valued much of physical education. The general gymnastics and military drill as the method of physical education practice were enforced separately but it treaded toward military character. As the method of physical education active, it was activated through athletic meet this day and the field day also exhibited the military organization and march. The filed day was supported greatly from Emperor and the queen to the general public, facility expenses and awarding prizes were appropriated local expenses in the government schools and appropriated the volunteers in the private schools, and whole general public participated positively in the rule of Japan since. Japan was afraid of a movement in the public because of anti-Japanese sentiment by the Japanese annexation and the dark ages came by instructions of abolition of the each union filed day.

閨訓類 歌辭의 德目 考察

이달원 개신어문학회 2004 개신어문연구 Vol.22 No.-

농업 기반시설의 내진성능 평가기법 - 동적 수치해석 중심으로-

이달원,김용성,Lee, Dal-Won,Kim, Yong-Seong 한국농공학회 2004 한국농공학회논문집 Vol.46 No.4

The evaluation technique of seismic performance on agricultural infrastructure based on dynamic numerical simulations, which Included a cyclic elasto-plastic and a viscoelastic-viscoplastic constitutive model to actual multi-layered ground conditions during large earthquake were performed by a liquefaction analysis in the present study. From the liquefaction analysis, it was verified that the models can give a good description of the damping characteristics and liquefaction phenomena of ground accurately during large event which induces plastic deformation in large strain range.

붕괴된 암반사면에서 역해석에 의한 내부마찰각의 추정

이달원,김갑중 한국농공학회 2003 한국농공학회논문집 Vol.45 No.6

In this study, the back analysis was performed by means of stereo-net, plane failure and block failure method to collapsed fields among the rock slopes designed by standardized criterion, and the internal frictions from the back analysis were compared with those used to reinforcement design.It was concluded that in the result of the analysis by means of stereo net, plain failure and block failure methods, the internal frictions used to re-design of collapsed slope underestimated 10 , 5 and 10 inaverage.At present, the internal friction on the design is used the experience value according to the state of weathering, but internal friction angle by the back analysis on collapsed slope with various methods were more reliable values than those from the present method. And it was concluded that re-design was made extravagantly because the internal friction used to re-design for reinforcement of the collapsed slope was less than back analysis.