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Cellular Cofferdam Design and Construction
No full text지난 50여년간 Cellular Cofferdam의 규모가 점점 커짐에 따라 하천 및 항만구조물 시공도 크게 발전하였다. 1910-1930년대의 초기단계에는 30-4Oft 높이이던 것이 최근에는 l15ft놀이까지 성공적으로 시공되었다. 모래층 위에 축조되기도 하나 대부분의Cellular Cofferdam은 암반 위에 축조되고 주로 모래, 또는 모래와 자갈로 채워진다. 본고는 Cellular Cofferdam의 발전단계, 종류, 설계절차를 여러 시공예와 함께 기술하였다.The construction of river and harbor structure has been developed largely in the last 50 years by cellular cofferdams of larger and larger dimensions and depths.
Beginning in 1910-1930 with head of 30 to 40 ft, a recent cofferdam has been constructed successfully to withstand a head of l15ft.
Most of cellular cofferdams were founded on rock with fill materials principally of sand, or sand and gravel, but several were founded on deep sand strata.
The types and design procedure are described with a presentation of construction examples and practical considerations.The construction of river and harbor structure has been developed largely in the last 50 years by cellular cofferdams of larger and larger dimensions and depths.
Beginning in 1910-1930 with head of 30 to 40 ft, a recent cofferdam has been constructed successfully to withstand a head of l15ft.
Most of cellular cofferdams were founded on rock with fill materials principally of sand, or sand and gravel, but several were founded on deep sand strata.
The types and design procedure are described with a presentation of construction examples and practical considerations
Experimental Study on the Attacking Phenomena of Iron by Molten Zinc
No full text극연강재(極軟鋼材)를 440∼570℃ 범위의 여러가지 온도에서 용융아연 중에 침적(浸 漬)하여 그 침식량과 반응시간 및 온도와의 관계를 실험 조사 하였다. 495℃에서 침식량은 이상적(異常的)으로 증가하고 그 반응시간에 직선적인 비례 관계를 갖는다는 점을 확인 하였다. 또한 440∼475℃온도 범위에서는 거의 변화가 없고 520℃ 이상에서는 침식된 철분이 이보다는 많으나 급격한 증가는 없었으며 이러한 침식량들은 반응시간의 제곱근에 비례하였다. δ₁과 ξ상(相) 간의 peritectic reaction은 Schramm의 상태도에서는 530℃에서 일어남에 비하여 495℃에서 일어났었다.
이러한 결과로 부터 얻을 수 있는 결론은 도금가마(Galvanizing Kettle)의 수명을 연장하기 위해서는 Kettle Wall 외측온도가 530℃가 되지 않도록 Local over-heating을 피하여야 하며 488℃를 표준으로 도금로(鍍金爐)를 설계하지 않으면 안된다는 점이다.The relation between the reaction time, temperature and the dissolved amount was experimentally investigated by dipping the extra mild steel in the molten zinc at different temperature within the range of 440-570℃.
It was found that the abnormal increase of dissolved amount took place at 495 ℃, and the relation of dissolved amount with respect to reaction time was lineary proportional. In the temperature region between 440-475℃, there were only the slight. changes and above 520℃, even though the amount of dissolved iron was larger, great increase could not be found and the dissolved amounts increased in proportion to the square root of the time. The peritectic reaction between δ₁and ξ phase took place at 495℃ in comparison to 530℃ in the Schramm's phase diagram. From these results, it was concluded that in order to lengthen the life of galvanizing kettle, it must be avoided for the outside temperature of kettle wall to reach 503℃ by local over-heating and the furnace for a kettle should be designed according to the standard temperature, 488℃.The relation between the reaction time, temperature and the dissolved amount was experimentally investigated by dipping the extra mild steel in the molten zinc at different temperature within the range of 440-570℃.
It was found that the abnormal increase of dissolved amount took place at 495 ℃, and the relation of dissolved amount with respect to reaction time was lineary proportional. In the temperature region between 440-475℃, there were only the slight. changes and above 520℃, even though the amount of dissolved iron was larger, great increase could not be found and the dissolved amounts increased in proportion to the square root of the time. The peritectic reaction between δ₁and ξ phase took place at 495℃ in comparison to 530℃ in the Schramm's phase diagram. From these results, it was concluded that in order to lengthen the life of galvanizing kettle, it must be avoided for the outside temperature of kettle wall to reach 503℃ by local over-heating and the furnace for a kettle should be designed according to the standard temperature, 488℃
Deformation of Cylindrical Shell
No full text직경에 비하여 두께가 작은cylindrical shell이 힘을 받아 변형을 일으켰을때 변위사이의 미분방정식을 구했다.
shell로부터 취한 미소요소의 측면들에 작용하는 힘과 moment는 strain 및 곡율변화로서 표시할 수 있고 다시 이들은 변위 사이의 미분형태로 표시 가능함을 보임으로써 이 미소요소에 작용하는 힘 moment의 평형조건을 사용하여 변위사이의 미분 방정식이 얻어졌다.Partial differential equations between the components if displacement are derived when a cylindrical shell, whose wall thickness is relatively small compared with the diameter, is deformed by the load.
The forces and moments acting on the sides of small element of the shell are expressed by the strain and the difference of the rate of curvature. Since it was possible to express these terms in the derivative forms of displacement. differential equations are obtained by using equilibrium condition on this small element.Partial differential equations between the components if displacement are derived when a cylindrical shell, whose wall thickness is relatively small compared with the diameter, is deformed by the load.
The forces and moments acting on the sides of small element of the shell are expressed by the strain and the difference of the rate of curvature. Since it was possible to express these terms in the derivative forms of displacement. differential equations are obtained by using equilibrium condition on this small element
전환 효율이 높은 무선주파 전력 증폭기회로
No full text무선주파 전력 증폭기 회로에서는 그 회로와 거기에 사용된 회로소자의 효율문제가 중요시 된다. 본 논문에서는 Transistor, 특히 단일 근성형인 FEF의 고유동작 특성을 유효하게 이용함으로써 무선주파 전력 증폭회로의 전환효율을 증대시키는 방안을 모색하였다.
먼저 C급 FET 무선주파 전력증폭기회로를 종전의 진공관 회로분석에 사용되는 반도해식 방법에 따라 분석하고 몇가지 유리한 특성들을 들었다.
다음으로 Pulse 여진형 FET 무선주파 전력 증폭기회로를 분석하고 이 회로소자의 특성상 한계를 논하였다.
끝으로 쌍극성 Transistor와 단일극성형인 Transistor의 단점을 각각 보완하도록 혼성회로를 구성하고 그 회로모델을 조립 시험한 다음 그 결과를 제시하여 이 혼성회로의 전환효율이 종래의 C급 전력 증폭기 보다 훨씬 높음을 실제로 보였다.The efficiency of the device and the circuitry is very important in an r-f power generation circuit. In this paper a study is made to see if any intrinsic operating characteristics of transistors, unipolar types in particular, can advantageously be utilized to generate r-f power effectively.
A conventional class C PET r-f power amplifier is analyzed following a semigraphical method similar to that used for vacuum tubes. Some advantageous characteristics of the device are discussed.
The applicability of FETs to pulse-excited r-f power generation circuit is investigated and the device limitations in this field of application are discussed.
Finally, the combined use of an FET and a conventional bipolar transistor, to overcome the respective limitations, in an efficient r-f power generation circuit is studied. A practical working model of this hybrid circuit whose conversion efficiency is much higher than those of conventional class C r-f power amplifier was built and tested to illustrate its advantages.The efficiency of the device and the circuitry is very important in an r-f power generation circuit. In this paper a study is made to see if any intrinsic operating characteristics of transistors, unipolar types in particular, can advantageously be utilized to generate r-f power effectively.
A conventional class C PET r-f power amplifier is analyzed following a semigraphical method similar to that used for vacuum tubes. Some advantageous characteristics of the device are discussed.
The applicability of FETs to pulse-excited r-f power generation circuit is investigated and the device limitations in this field of application are discussed.
Finally, the combined use of an FET and a conventional bipolar transistor, to overcome the respective limitations, in an efficient r-f power generation circuit is studied. A practical working model of this hybrid circuit whose conversion efficiency is much higher than those of conventional class C r-f power amplifier was built and tested to illustrate its advantages
The Symbolism of W.B.Yeats
No full text作家는, 特히 重要한 作家는 그때그때의 靈感에 의지하여 간헐적으로 作品活動을 하지 않는다. 부단한 執念과 一貫된 비죤을 가지고 能動的으로 靈感을 환기하여 꾸준히 作品活動을 하는 것이다. 이 글은 그러한 가정을 전제로 하여 쓰였다.
예이츠에게 있어서 詩를 쓰는 일은 象徵을 찾아내고 만들어내는 일이었다. 그의 방대한 산문과 구체적인 詩가 이것을 증명하고 있다. 따라서 예이츠의 詩의 世界에 접근하는 가장 올바른 길은 그의 象徵主義를 극명하고 이해하는데 있다.
예이츠의 象徵主義는 原型論的 象徵에서 출발했는데, 이것이 深化와 擴大過程을 거쳐 리얼리즘까지 포함하고, 리얼리즘을 상징화하는 경지로 성숙하는 운동패턴을 이루었다. 이 글에서는 그러한 운동패턴을 고찰하였다.It has generally been the orthodox position to divide Yeats's poetic career into two periods and to look upon his earlier work as quite inferior to his later work as if they had no interrelation with each other. But I have found, with aids of some Yeats's scholars, that we can seek for the continuity or integrity of his whole poetry in terms of symbolism, which I believe offers a most illuminating clue to his poetic achievements.
Yeats's symbolism has two main characteristics; evocative and unifying. His symbolism was concerned primarily with the hidden wisdom coming down from the very beginning of the history. But his symbolism, which aimed at the unity of being as the final goal, was extended to include the actuality. The actual experiences and events were used as poetic symbols which could reveal the hidden reality, because he thought they are the forms which are brought into being by touch with the great memory.
By symbolism he could enhance a personal experience up to an experience of universal significance. By symbolism he could also make the typical concrete and personal. It is thus by symbolism that he could give the unified form both to the dualistic struggle of ideality and actuality and to the conflict of universality and individuality.It has generally been the orthodox position to divide Yeats's poetic career into two periods and to look upon his earlier work as quite inferior to his later work as if they had no interrelation with each other. But I have found, with aids of some Yeats's scholars, that we can seek for the continuity or integrity of his whole poetry in terms of symbolism, which I believe offers a most illuminating clue to his poetic achievements.
Yeats's symbolism has two main characteristics; evocative and unifying. His symbolism was concerned primarily with the hidden wisdom coming down from the very beginning of the history. But his symbolism, which aimed at the unity of being as the final goal, was extended to include the actuality. The actual experiences and events were used as poetic symbols which could reveal the hidden reality, because he thought they are the forms which are brought into being by touch with the great memory.
By symbolism he could enhance a personal experience up to an experience of universal significance. By symbolism he could also make the typical concrete and personal. It is thus by symbolism that he could give the unified form both to the dualistic struggle of ideality and actuality and to the conflict of universality and individuality
좌 Artin환에서의 라디칼의 특성
No full text본 논문에서는 R을 좌 Artin환, N을 Jacobson 라디칼 이라할때 좌 R-module C가 단순 R-submodule의 직화로 표시되기 위한 필요하고도 충분한 조건은 NC=0임을 보인다.
그리고 더욱 나아가서 R-module ?A에서 R-module ?B로 가는 모든 R-module 준동형의 집합은 하나의 R-module이 될 수 있는데 이것이 R/N-module A/NA에서 R/N-module C로 가는 모든 R/N-module 준동형의 집합과 동형임을 밝힌다.It is shown that a left R-module C can be represented as a direct sum of simple R-submodules if and only if NC=0, where R is left Artinian, and N is the Jacobson radical of R. Furthermore, it is proved that if R is a left Artinian ring, N the radical of R, and NC=0, then Hom?(A,C)?Hom???(A/N A, C), where Hom? (A, C) is the set of all R-module homomorphisms of an R-module ?A to ?B.It is shown that a left R-module C can be represented as a direct sum of simple R-submodules if and only if NC=0, where R is left Artinian, and N is the Jacobson radical of R. Furthermore, it is proved that if R is a left Artinian ring, N the radical of R, and NC=0, then Hom?(A,C)?Hom???(A/N A, C), where Hom? (A, C) is the set of all R-module homomorphisms of an R-module ?A to ?B
Inverse System의 연구
No full text우리는 Category에서 Universally Repelling과 Universally Attracting의 성짙을 이용하여 중요한 대수적인 성질과 위상적인 성질을 얻어 냈다. 그런데 본 Paper에서는 Continuous Ring Homomorphism을 갖는 Topological Ring의 category에서 새로운 Category ?를 다음과 같이 만들어 ?에서의 Universally Attractimg한 Object가 본래의 Category의 Inverse Limit가 된다는 것을 얻었다.
Category ?의 Object들은 (A,(f?))로 되어 있으며 A는 Category ?의 Object이고 (f?)는 Continuous Ring Homomorphism의 Family이다.
그러면서 다음 Diagram을 Commutative하게 한다.
????( 그 림 )?????
Fig. 2
여기서는 Category ?의 Object는 Topological Ring이고 Morphism들은 Continuous Ring Homomorphism들이다.The purpose of this paper is to find a universal element in the category ?. Ob(?) consists of pairs(A,(f?)) where AεOb(?) (? is also a category whose objects are topological rings and morphisms are continuous ring homomorphisms) and f?:A?→A,iεI; continuous ring homomorphism, such that for all i≥j the following diagram is commutative.
????( 그 림 )?????
Fig. 1The purpose of this paper is to find a universal element in the category ?. Ob(?) consists of pairs(A,(f?)) where AεOb(?) (? is also a category whose objects are topological rings and morphisms are continuous ring homomorphisms) and f?:A?→A,iεI; continuous ring homomorphism, such that for all i≥j the following diagram is commutative.
????( 그 림 )?????
Fig.
Determination of Sulfur in Hydrocarbon by Low Energy γ-ray Absorption Par(Ⅰ)
No full text물질의 Mass absorption coefficient 차이를 이용하여 Hydrocarbon중에 불순물로 포함되어 있는 유황을 신속 정확히 정량할 수 있는 방법을 이론적으로 고찰하였다. 유황, 수소 및 탄소의 γ-선에 대한 Total attenuation coefficient는 근사식을 써서 계산한다. γ-선의 에너지 범위는 10∼80KeV정도가 적당하고 Gamma-emitting isotope로서는 ²⁴¹Am, ¹??Tm, ²?²Cf, ²³²Th, ²³?U등이 실제 분석에 유용할 것이다.Possibility of a rapid and acurate determination of Sulfur in hydrocarbon was checked theoretically by means of its particular mass absorption coefficient. Total attenuation coefficient of electrom-agnetic radiation in Sulfur, Hydrogen and Carbon were calculated by means of the approximation formula. Useful γ-ray energy ranges were from 10 to 80 KeV, so that only a weak gamma-emitting radioisotopes such as ²⁴¹Am, ¹??Tm, ²?²Cf, ²³²Th, ²³?U seem to be very useful for the practical analysis.Possibility of a rapid and acurate determination of Sulfur in hydrocarbon was checked theoretically by means of its particular mass absorption coefficient. Total attenuation coefficient of electrom-agnetic radiation in Sulfur, Hydrogen and Carbon were calculated by means of the approximation formula. Useful γ-ray energy ranges were from 10 to 80 KeV, so that only a weak gamma-emitting radioisotopes such as ²⁴¹Am, ¹??Tm, ²?²Cf, ²³²Th, ²³?U seem to be very useful for the practical analysis
알미늄 분석법
No full text필자는 1970년 이전의 약 20년간에 보고 되었던 알미늄 금속의 분석법에 관한 논문들을 다시 검토해 보았다. 1970년대 이전에 발표된 문헌들로 미루어 보아 그 당시에는 미량 성분의 알미늄 금속 분석에 판한 연구가 그다지 활발하지 못했다 하겠다. 그러나 필자가 조사한 기간에는 미량 성분의 분석에 관한 연구가 괄목할 만큼 두드러지게 나타났으며 용량 분석방법이 특히 많이 쓰였음을 엿볼 수 있었다. 기타 중량법과 흡광 분광 광도법, 분광 헝광 분석법, 발광 분광 광도법, 방사화 분석법 등등의 기기분석 방법이 공업적으로 점차 많이 쓰였음을 알 수 있었다.
분석 방법은 금속의 정제적인 이용도가 개밭됨에 따라 실지로 현저하게 발전되었음을 보고된 문헌을 통하여 알 수 있다. 요즈음에는 핵화학에 관한 기술이 고 순도 물짙이나 합금들에 들어 있는 극미량의 알미늄을 정확하게 정량하는 극히 좋은 수단이 되고 있는것 같다.
지난 20년간에 좋은 방사 화화적인 분석법과 분리 방법이 급증하였지만 우리 나라 공업계에서는 아직도 이에 관한 새로운 기술의 결핍으로 공정의 제품 관리에 사용되고 있지 않다.The analytical methods of aluminum metal are reviewed for about 2 decades up to 1970.
Prior to the past two decades few accurate quantitative methods were recorded for the determination of micro amount of aluminum.
Volutmetric methods were widely used particularly for this aluminum metal. Colorimetric, spectrofluorometric, X-ray fluorescence, spectrographic, and gravimetric methods are also applied in industrial purposes. Generally it is a fact that coincident with a improvement in the economic status of a metal, there is a corresponding impetus in the development of methods for its analytical determination. Along with the great improvement in the economics of the aluminum metals and its alloys are found a really significant advance in the recorded analytical methods for aluminum in various matrices. Recently the nuclear chemical techniques may be considered very powerful tools for an accurate determination of submicrogram amount of aluminum in high purity materials or in alloys. The past two decades have seen a rapid increase in the number of effective analytical methods of separation and determination.
Despite of the accumulation of the data, it seems to be very hard to manage for their routine work in an industry because of their lackness of new knowledge of nuclear and radiochemistry in the developing country like Korea.The analytical methods of aluminum metal are reviewed for about 2 decades up to 1970.
Prior to the past two decades few accurate quantitative methods were recorded for the determination of micro amount of aluminum.
Volutmetric methods were widely used particularly for this aluminum metal. Colorimetric, spectrofluorometric, X-ray fluorescence, spectrographic, and gravimetric methods are also applied in industrial purposes. Generally it is a fact that coincident with a improvement in the economic status of a metal, there is a corresponding impetus in the development of methods for its analytical determination. Along with the great improvement in the economics of the aluminum metals and its alloys are found a really significant advance in the recorded analytical methods for aluminum in various matrices. Recently the nuclear chemical techniques may be considered very powerful tools for an accurate determination of submicrogram amount of aluminum in high purity materials or in alloys. The past two decades have seen a rapid increase in the number of effective analytical methods of separation and determination.
Despite of the accumulation of the data, it seems to be very hard to manage for their routine work in an industry because of their lackness of new knowledge of nuclear and radiochemistry in the developing country like Korea