• 한국안전학회지
• /
• 제24권5호
• /
• pp.43-47
• /
• 2009

Armor block is used to reduce wave energy. To do this, the stability of coastal structure is enhanced. It is very expensive to develop a new type armor block. So, the research of new type armor block is very short. We develope truncated tetrahedron type armor block(new type block) which have a hole in center part. In this study, the stability of new type armor block is investigated by hydraulic model test. In the result, the stability coefficient($K_D$) of new type armor block is 11.8. this value is more superior than value of tetrapod.

• 교육시설
• /
• 제8권1호
• /
• pp.5-14
• /
• 2001

The purpose of this study is to clarify the block type of school buildings based on present conditions, by picking up elementary school buildings of Chungbuk Province in Korea. The summary of the block types can be given below. 1) Elementary school buildings(495) in Chungbuk Province are almost built in an average block of 1.7school(290). 2) The block types of school buildings are classified with "-", "ㄱ", "ㄷ", and parallel type. There are many "-" types over and parallel types in the second place of them. 3) The "-" block types are uniformly distributed with 166 elementary schools, below 6 classroom, 7through 24classrooms, beyond 25 classrooms. The "ㄱ" block types are 8 schools, and built as the wing of "-" block type in a limited space. The parallel types are classified with 2 3 lines according to the numbers of paralleled school buildings. The 2 parallel types are firstly represented with more than 95 classrooms, and 5 schools of "ㄷ" types, built as the wing of 2 parallel types, are only represented over 25 classrooms. The 3 parallel types are only 16 schools of all. They are uniformly seen in old and new school buildings.

• 한국환경복원기술학회지
• /
• 제23권3호
• /
• pp.91-104
• /
• 2020

This study was conducted to analyze the characteristics of defects according to the type of block and spatial type by quantitatively examining defects occurring in block pavement in apartment complex. According to the research results, depending on the type of block, defects have occurred 1,394.3ea/100㎡ in interlocking paver blocks, 464.8ea/100㎡ in clay brick paver blocks, and 235.1ea/100㎡ in shot blasted paver blocks. By space type, the defects were occurred 1,576.0ea/100㎡ on the access road paved by interlocking paver blocks and the defects were found 1,139.6ea/100㎡ in interlocking paver blocks, 235.1ea/100㎡ in shot blasted paver blocks, and 797.1ea/100㎡ in clay brick paver blocks, on the sidewalk. Also the defects are occurred 455.6ea/100㎡ on the resting space and 403.2ea/100㎡ on the gym space paved by clay brick paver blocks. Through the size analysis of the defects in the block paver, in the case 'peeling', the largest volume of 2,539.0㎣ on the sidewalk paved with shot blasted paver blocks, and 'Subsidence' occurred at the widest area of 2,096.0㎠ on the sidewalk where interlocking paver block was constructed. The difference in defect occurrence according to the type of block is considered to be influenced by the block production process, and the space type is considered to be caused the difference in the occurrence of defects according to the cause of construction and the usage pattern of residents. This study conducted a survey on defects in block and analyzed the defect characteristic according to paver material and space type. Base on this, it is judged that it can be used as an efficient basic data for material replacement, improvement, paver planning and construction in the future.

• 컴퓨터교육학회논문지
• /
• 제19권6호
• /
• pp.55-68
• /
• 2016

2015 개정 정보과 교육과정에서는 문제해결과 프로그래밍 단원을 나선형으로 조직하면서 학교급 별로 블록형과 텍스트형 프로그래밍 언어의 사용을 제안하였다. 본 연구는 프로그래밍 학습에서 알고리즘 작성이 프로그래밍 학습에 도움을 주는지, 블록형 프로그래밍 학습이 텍스트형 프로그래밍 후행학습에 긍정적 전이효과가 있는지를 확인하기 위한 목적으로 진행되었다. 목적 달성을 위해 초등학생 15명을 대상으로 블록형과 텍스트형 프로그래밍 학습을 진행하였다. 연구 결과, 한정된 방법으로 알고리즘을 작성하는 것은 학습자들의 사고 표현을 가로막을 수 있지만 블록형 프로그래밍 학습은 텍스트형 프로그래밍 학습에 긍정적 전이가 있음을 확인하였다. 본 연구는 초등학교부터 계열성 있는 프로그래밍 교육을 위한 방안을 제시하였다는 것에 의의가 있다.

• 정보보호학회논문지
• /
• 제9권3호
• /
• pp.27-38
• /
• 1999

DC 및 LC에 대하여 증명 가능한 안전성을 제공하는 2-블록 구조를 라운드 함수의 위치에 따라 서 C(Center)-형 R(Right)형 L(Left)-형으로 구분하고 각각에 대한 고차 차분 공격 측면의 안전성을 분 석한다. 4라운드 암호화 함수인 경우 세가지 2-블록 구조는 고차 차분 공격에 대하여 동일 한 안전성을 제공한다는 사실을 증명하며 5라운드 이상의 암호화 함수에 대해서는 병렬 연산이 가능한 R-형 구조가 C-형과 l-형에 비해서 계산 효율성은 높지만 고차 차분 공격 측면의 안전성은 떨어진다는 사실을 밝힌 다. We study on the security for the block ciphers with 20block structure which have provable security against DC and LC on the view point of higher order DC, 2-block structures are classified three types according to the location of round function such as C(Center)-type R(Right)-type and L(Left)-type We prove that in the case of 4 rounds encryption function these three types provide the equal strength against higher order DC and that in the case of 5 or more rounds R-type is weaker than C-type and L-type.

• The Korean Journal of Pain
• /
• 제12권1호
• /
• pp.75-80
• /
• 1999

Background: Despite tension type headache is popular, the exact mechanism and method of treatment are not certain yet. So, we supposed the basic mechanism of tension type headache is myogenic, and did Tienchu acupoint block, occipital nerve block, and trigger point injection in tension type headache patients. Methods: Fifty-seven tension type headache patients were treated with local anesthetics and small dose of steroid. The intensity of pain and effect of every treatment was evaluated as Verbal Rating Score (VRS; 0~10) before and after every treatment. Evaluation of treatment was based on the time of treatment (1,2 times, 3 times, 4,5 times). Goal of treatment was VRS reaching below two point and it was considered as treated state. Results: Symptom improvement rates of each treatment were 90% (1, 2 times), 91% (3 times), 70% (4, 5 times) respectively. VRS reduction more than 50% rates were 60%, 64%, 60% respectively. Treated state (VRS<2) rates were 33%, 27%, 30% respectively. Conclusion: Tienchu acupoint block, occipital nerve block, trigger point injection were sorts of most effective and simply applicable modalities of treatment in tension type headache.

• The Korean Journal of Pain
• /
• 제8권2호
• /
• pp.225-234
• /
• 1995

Low back pain(LBP) is one of the most common ailment. There were two type of LBP in the clinic. One of them is low back pain with leg pain, the other one is low back pain without leg pain. Author explain the reasons, characters. mechanism, diagnosis, and reported 156 cases of LBP. There are various method to treatment of low back pain in recent. The first selection for treatment of LBP were intervertebral block added "+" type block(IVP "+" TB). according to author's experience, the rate of Excellent and good were account for 96.2%. Other method of LBPO therapy were also used in Pain clinic, such as psoas compartment block, caudal block, epidural steroid block, zygapophysial joint block, nerve root block, subarachnoid neural block, Lumbar sympathetic block, etc. Finally, author introduced Pain clinic in China. divided to three titles: (1) history, (2) CASP and scientific activity, (3) pain therapy in China.

• Tribology and Lubricants
• /
• 제20권4호
• /
• pp.209-217
• /
• 2004

Lubrication characteristics between a cylinder block and a valve plate for high speed bent-axis type hydraulic pump play an important role in volumetric efficiency and durability of pump. In this paper, a finite element method is presented for the computation of the pressure distribution between a cylinder block and a valve plate for high speed bent-axis type hydraulic pump. Also, a Runge-Kutta method is applied to simulate the cylinder block dynamics of three-degrees of freedom motion. From the results of computation, we can draw two major conclusions. One is related to the fluid film characteristics between a cylinder block and a valve plate and the other is related to the average leakage that is determined by the pressure gradient and the clearance near the discharge port. The numerical results of cylinder block dynamics were compared with the experimental results using eddy-current type gap sensors those are fixed at a pump housing.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
• /
• pp.743-748
• /
• 1997

In this paper, a new type of precast perforated concrete block is presented to be used in the construction of a step seawall. The overtopping rate of the perforated step seawall is lower than that of the traditional non-perforated step seawall. In construction stage, the cost of total construction of the perforated block is cheaper than that of traditional block. The new type of perforated block may be used as an alternative for shore protection facility.

• Bulletin of the Korean Chemical Society
• /
• 제22권5호
• /
• pp.467-475
• /
• 2001

A triblock copolymer based on $poly(\varepsilon-caprolactone)$ (PCL) as the hydrophobic part and poly(ethylene glycol) (PEG) as the hydrophilic portion was synthesized by a ring-opening mechanism of ${\varepsilon}-caprolactone$ with PEG containing a hydroxyl group at bot h ends as an initiator. The synthesized block copolymers of PCL/PEG/PCL (CEC) were confirmed and characterized using various analysis equipment such as 1H NMR, DSC, FT-IR, and WAXD. Core-shell type nanoparticles of CEC triblock copolymers were prepared using a dialysis technique to estimate their potential as a colloidal drug carrier using a hydrophobic drug. From the results of particle size analysis and transmission electron microscopy, the particle size of CEC core-shell type nanoparticles was determined to be about 20-60 nm with a spherical shape. Since CEC block copolymer nanoparticles have a core-shell type micellar structure and small particle size similar to polymeric micelles, CEC block copolymer can self-associate at certain concentrations and the critical association concentration (CAC) was able to be determined by fluorescence probe techniques. The CAC values of the CEC block copolymers were dependent on the PCL block length. In addition, drug loading contents were dependent on the PCL block length: the larger the PCL block length, the higher the drug loading content. Drug release from CEC core-shell type nanoparticles showed an initial burst release for the first 12 hrs followed by pseudo-zero order release kinetics for 2 or 3 days. CEC-2 block copolymer core-shell type nanoparticles were degraded very slowly, suggesting that the drug release kinetics were governed by a diffusion mechanism rather than a degradation mechanism irrelevant to the CEC block copolymer composition.