The adhesive design of a fast steering mirror transmitting a high power laser is one of the important design elements that affect optical aberration of the mirror surface. In this paper, we designed the adhesive part to avoid the high power laser beam of the FSM system. Stiffness and wavefront error are trade-off relationships and an optical design was derived to maintain the wavefront error of the mirror surface at high temperatures while satisfying the bandwidth of the FSM system. For the optimal design of the mirror bonding position, structural analysis was conducted using ANSYS and wavefront error analysis was performed using Zernike polynomial code. Through those analysis, FSM most effective at an angle 60 degrees and a distance of 46mm.

Along with the current rapid development of technology, object classification is being researched, developed, and applied to security systems, autonomous driving, and other applications. A common technique is to use vision cameras to collect data of objects in the surrounding environment. Along with many other methods, LiDAR sensors are being used to collect data in space to detect and classify objects. By using the LiDAR sensors, some disadvantages of image sensors with the negative influence on the image quality by weather and light condition will be covered. In this study, a volumetric image descriptor in 3D shape is developed to handle 3D object data in the urban environment obtained from LiDAR sensors, and convert it into image data before using deep learning algorithms in the process of object classification. The study showed the potential possibility of the proposal and its further application.

후쿠시마 원전사고 발생으로 다수기의 지진안전성에 관한 연구의 필요성이 부각되었다. 한 부지에 건설된 원자력발전소의 경우 유 사한 지진응답을 보이기 때문에 적게나마 원자력발전소 SSCs간의 지진손상에 대하여 상관성이 존재하므로 합리적 지진안전성 평가 를 위하여 지진손상 상관성을 고려하여야 한다. 본 연구에서는 쌍둥이 호기의 필수전원상실사건에 대하여 확률론적 지진안전성 평가 를 수행하였다. 적절한 지진손상 상관계수를 도출하기 위하여 확률론적 지진응답해석을 수행하여 적용하였다. External Event Mensuration System 프로그램을 활용하여 다수기의 필수전원상실사건의 고장수목을 구성하여 지진취약도 및 지진리스크를 분석하 였다. 또한 SSCs간의 지진손상 상관성을 완전독립 및 완전종속으로 고려하여 비교 분석을 수행하였다.

The SnSe single crystal shows an outstanding figure of merit (ZT) of 2.6 at 973 K; thus, it is considered to be a promising thermoelectric material. However, the mass production of SnSe single crystals is difficult, and their mechanical properties are poor. Alternatively, we can use polycrystalline SnSe powder, which has better mechanical properties. In this study, surface modification by atomic layer deposition (ALD) is chosen to increase the ZT value of SnSe polycrystalline powder. SnSe powder is ground by a ball mill. An ALD coating process using a rotary-type reactor is adopted. ZnO thin films are grown by 100 ALD cycles using diethylzinc and H2O as precursors at 100oC. ALD is performed at rotation speeds of 30, 40, 50, and 60 rpm to examine the effects of rotation speed on the thin film characteristics. The physical and chemical properties of ALD-coated SnSe powders are characterized by scanning and tunneling electron microscopy combined with energy-dispersive spectroscopy. The results reveal that a smooth oxygenrich ZnO layer is grown on SnSe at a rotation speed of 30 rpm. This result can be applied for the uniform coating of a ZnO layer on various powder materials.

This study investigates the historical development of English education in South Korea regarding the fourth and fifth National Curriculum Period. By analyzing the newspaper articles in five major newspapers in Korea, we focused on the characteristics of English education in each period. The research questions are: 1) what are the characteristics of the fourth National Curriculum? 2) what are the characteristics of the fifth National Curriculum?, and 3) what is the implication of these previous curricula on the current English education in South Korea? During the fourth National Curriculum Period, after the successful hosting of the 1986 Asian Games and the 1988 Summer Olympic Games in Seoul, the importance of communication skills in English spread throughout the country. Accordingly, the need for early English education emerged. In the fifth curriculum, various social factors, including the liberalization of overseas travel, led positive washback effects on English education. In elementary schools, English instructions were conducted as a special activity. In secondary schools, various changes in the educational environment were involved, including the introduction of listening tests and recruitment of native English teachers, which still affects English education in 2020. This paper concludes with educational implications and future research directions.

In this study, an effervescent atomizer capable of mixing and spraying vegetable oil and kerosene at the same time was proposed to examine the usefulness of vegetable oil and kerosene in terms of recycling of renewable energy and waste resources. The effect of nozzle exit diameter variation on the atomization characteristics such as spray angle, droplet size distribution, cumulative volume distribution, and SMD was investigated using LDPA. The results of this study showed that the spray angles decreased with increasing ALR at the same nozzle exit diameter and increased with increasing nozzle exit diameter under the same ALR condition. SMD was decreased with increasing ALR at all nozzle exit diameters, and SMD was decreased with decreasing nozzle exit diameter even under the same ALR conditions. Also, the droplet was more finely atomized when the nozzle exit diameter is reduced under the same ALR conditions and when the ALR is increased at the same nozzle exit diameter, but the uniformity of the droplets was lowered because the droplet with a larger diameter existed.

This paper explores the historical development of English education in Korea regarding the second and third National Curriculum period. By using the historical research method which analyzes newspaper articles in four major newspapers in Korea, we compared the similarities and differences between these two periods. The research questions are: 1) what are the characteristics of the second National Curriculum? 2) what are the characteristics of the third National Curriculum?, and 3) what is the implication of these previous curricula on the current English education in Korea? It was found that the second National Curriculum Period showed steady development in English education in terms of its emphasis on oral skills instead of the traditional emphasis on reading and grammar skills. However, the lack of coherence among various English textbooks, the lack of English teachers fluent in English, and the exam-oriented social atmosphere were the significant challenges in fully implementing the second National Curriculum. The third National Curriculum Period overlaps with the Yushin Regime propagated by the late President Park Junghee. During this period, a systematic effort to introduce communicative language teaching continued, whereas the exam-orientation persisted which made the English class employ teacher-centered grammar-translation methods. This paper concludes with educational suggestions and future research directions.

울산지역 청동기시대 종말기의 양상을 검토하였다. 검단리유형의 마지막 단계 유적과 초기철기시대 유적을 검토하여 울산지역의 양상이 한반도 다른 지역과 어떤 공통점과 차이점이 있는지를 살펴보았다. 검단리유형은 새롭게 유입된 점토대토기문화와 함께 와질토기 등장시점까지 존속한다. 울산지역은 지역적인 특성상 한반도 점토대토기의 종착지이다. 달천철장에서 알 수 있듯이 철광상을 발견하여 이용하였으며, 그 철을 매개로 낙랑, 일본 등과 활발한 대외교류 활동을 하였다. 점토대토기인의 생활터전이 이미 무문토기인들의 점유지였던 것으로 볼 때 양 집단의 갈등이 상대적으로 미약했다고 할 수 있다. 무문토기인들이 와질토기 등장시점까지 원래의 생활방식을 유지하면서 새로운 점토대토기문화를 자연스 럽게 받아들였다. 우리가 청동기시대의 유구라고 인식하였는데 실제 초기철기시대에 존속하였던 것이 많 을 것이다. 초기철기시대의 청동기시대적 요소는 목관묘 문화가 자리 잡으면서 완전히 소멸한다. 이때야말로 청동기 시대 종언하고 새로운 시대가 열리는 시점이다. 한반도 남부지역이 동아시아 질서에 편입되는 시점이라고 할 수 있다.

점적기의 성능은 압력보상 기능에 따른 유량 균등성에 의해 좌우되고, 유량의 균등성은 점적기 내부 의 위치에 따른 공급압력이 일정할 때 이루어진다. 점적기의 압력보상은 탄성을 가진 연질의 실리콘과 미로가 동시에 결합된 경우에 가장 큰 효과를 나타낸다. 그러나 경질 미로만으로 구성된 점적기의 경우 에는 미로의 길이와 내부구조에 따라 유량이 크게 달라진다. 경질 미로만으로 구성된 점적기의 경우에는 연질의 실리콘을 동시에 결합한 점적기보다 공급 압력에 따른 유량의 오차가 훨씬 크게 나타나므로 간편한 반면에 성능에서는 불리한 조건을 가진다. 경질미로로 구성된 점적호스의 경우 공급 압력과 미로의 길이와 단면에 따른 최적 설계를 통하여 적절한 조건에서 폭넓게 사용할 수 있는 장점이 있으므로 이에 대한 연구는 점적기의 성능을 개선하는데 매우 중요한 역할을 한다. 그러나 이러한 분야의 연구는 거의 이루어지지 않은 실정이다. 따라서 본 연구에서는 경질미로로 구성된 점적호스의 성능평가를 구명 하기 위해 원형의 미로를 길이별로 8단계(#1~#8)로 나누어, 공급압력(0.5~3.0bar) 변화에 따른 출구유량을 실험적 방법과 이론적 해석(CFD)으로 구하였다.

The qualities of rice cooked on heat plate, induction heat and heat plate with pressure, were investigated. The weight, volume, water soluble index (WSI), hydration by SEM (Scanning Electron Microscope), and gelatinization by DSC (Differential Scanning Calorimetry), as well as the consumer acceptability of cooked rice were analyzed. The weight, volume and WSI of rice cooked on heat plate with pressure were higher than those of rice cooked on heat plate and induction heat. The rice cooked on heat plate with pressure also showed higher degree of hydration and gelatinization, and lower degree of enthalpy of gelatinization than the rice cooked on heat plate and induction heat for 5~15 min. The consumer acceptability revealed that the odor, appearance, taste, texture and overall acceptance of rice cooked on induction heat were better than those of rice cooked on heat plate and heat plate with pressure. During storage in a cooker for 0~12 h, there was a decrease in the consumer acceptability of cooked rice. Overall results indicate that the qualities of rice cooked on induction heat and heat plate with pressure were higher than those of rice cooked on heat plate.

This paper presents the results of test observations toward a point source, 4C39.25, for observation modes with various bandwidths and numbers of IF streams in order to examine a reliability of the Daejeon hardware correlator performance for correlating VLBI (Very Long Baseline Interferometry) data obtained with the several observation modes of the KVN (Korean VLBI Network). We used a DiFX software correlator (DiFX) as a reference, for investigating the output visibilities from the Daejeon corelator. It is found that the band shapes of the output visibilities from two correlators are similar to each other and the correlated flux density for each baseline obtained from the Daejeon hardware correlator is lower by 3 - 7% than that from the DiFX. The flux difference is attributed to the limitation of FPGA resources and the difference of fringe rotation algorithm of the Daejeon hardware correlator. The conversion factor, 0.93 ~ 0.97, is proposed for future correlation with the Daejeon hardware correlator.

The relationship between Li Qingzhao and Buddhism has been less concerned. Self‐titled Yi’an Jushi,it couldn’t just be the reason of self‐loftiness. From the research of existing historical data, family misfortune, seedless and the influence of friends and family were the main reasons made Li Qingzhao approached to Buddhism. From the use of her Ci‐poetry allusion, imagery and realm,we can also find Li Qingzhao’s attitude about Buddhism. And with a new view of Buddhism, the problems such as the choice of imagery, the method of rhetoric and the style of Li Qingzhao’s Ci‐poems can be interpreted in a new way. Because of her unique life experience, Li Qingzhao approached Buddhism to relief the pain of life, and organic merged Buddhist thought into her works. The sadness and beauty of Li Qingzhao’s works just come from this. So, “Li Qingzhao’s indifference to Religion” is worth discussing, and the relationship between female Buddhist literati and Buddhism is still a subject worthy of further exploration and study.

Cleanroom could be largely classified into industrial cleanroom that can be contaminated by particlesand bio-cleanroom that can be contaminated by biological particles. Electrical manufacturing companies such as precision machines and electrical parts essentially have industrial cleanroom facilities and clean technologies to produce defects free products due to particles.Industrial cleanroom should be controlled in respect of 4M1E to prevent from foreign materials of submicro unit and to keep out contamination sources from outside. In this paper, a concept for a quantitative methodology to measure the particles from running components was suggested by combining both newly making clean booth such as wear tester and laser particle counter.

This study is to develop a ring binder which deals with punching process and ring pressing process consecutively for twin ring binding. The purpose of this study is to develop a vertical ring binder which operates punching and binding process in unification by using a power source. It is expected to reduce the personnel expenses more than 40% by uniting the two ring binding processes, which are imported products, into this trial manufacture. It is also expected to decrease the diversion of foreign currency by substituting imported electric ring binder, which costs almost 10 billion won in a year, to this binder.

빈산소 수괴는 전세계적으로 얕은 연안의 바다에서 생태적으로 위협적인 영향을 미치고 있다. 한반도 남해동부연안의 가막만에서도 2007년 6월 말에 빈산소 현상이 나타났으며, 빈산소 수괴 소멸기의 이화학적 특성을 조사하였다. 빈산소 수괴는 선소 인접지역에서 북서부 내만역의 연안을 따라 형성되어 있었다. 표층수와 저층수의 용존산소 농도는 빈산소 수괴에서 1.3mgL-1와 2mgL-1 이하, 그 외 지역은 각각 4.5~6.8mgL-1와 3.8~6.0mgL-1로 양호한 농도를 보였다. 빈산소 지역의 클로로필 a 농도는 표층 4.9~25.3μgL-1, 중층이 2.3~23.1μgL-1, 저층은 1.9~9.0μgL-1 범위였다. 가막만 빈산소 수괴의 발생은 3가지 수직적 형태로 나타났다. 첫 번째는 선소 주변에서 빈산소 수괴가 전 수심 층에서 발생되면서 어 패류의 폐사가 일어났다. 두 번째는 일반적인 빈산소 수괴 발생 형태인 저층에서부터 빈산소가 발생되어 있는 상태였다. 세 번째는 수온 역전 현상이 일어나면서 중층에서만 빈산소 수괴가 발생하였고 저층에는 빈산소 수괴가 발생하지 않았는데, 이러한 현상은 조사정점 9, 14 및 21의 호도마을 인접지역 연안에서만 발생하였다. 빈산소 수역에서는 해저면에 주로 서식하는 문절망둑 무리들이 수면위로 올라와 산소 결핍에 따른 입 올림을 하였으며 게류 및 고둥류 등이 갯가로 올라오는 등 이상행동을 하는 것이 관찰되었다. 폐사된 생물들은 주로 문절망둑으로서 3천 마리 정도였고, 게 및 고둥류 일부가 폐사하였다.

It has been considered that 'exhausted eclipses' (日食旣) were total eclipses. However, modern precise calculations show that a significant fraction of such records are not realized to be total. Thus we doubt that the two concepts are equivalent. Here we investigate the meaning of 'exhausted eclipses' in the east-Asian history. We first find that eclipses of magnitude greater than 0.8 were regarded as 'exhausted eclipses' by a Korean astronomer of the 18th-century Choson dynasty. His notion was based upon the definition of 'exhausted eclipses' in the ephemerides of pre-modern Chinese dynasties. According to those ephemerides, the 'exhausted eclipses', whose magnitude is greater than 0.8, have the first contact at the western part of the solar disk and the fourth contact at the eastern part of the solar disk. A simple geometrical calculation shows that such cases really occur when the magnitude of eclipse is greater than 0.7. We pointed out that such an ancient definition might not be impractical for ancient astronomers, because the uncertainty of eclipse magnitude estimated by ancient Chinese ephemerides was 10% and the human sight has a spatial resolution of 1.2 arcmin, which is approximately one twentieth of the Sun's angular diameter.