한국산 미기록 종인 네무늬구멍썩덩벌레붙이(Lissodema plagiatum Lewis) (신칭)를 한반도에서 처음으로 보고하고, Lissodema laevipennis Marseul의 한국 기록을 삭제한다. 한국산 썩덩벌레붙이과에 대한 종 검색표와 미기록 종에 대한 사진과 분류학적 의견을 제시한다.

Surface plasmon resonance is the resonant oscillation of conduction electrons at the interface between negative and positive permittivity material stimulated by incident light. In particular, when light transmits through the metallic microhole structures, it shows an increased intensity of light. Thus, it is used to increase the efficiency of devices such as LEDs, solar cells, and sensors. There are various methods to make micro-hole structures. In this experiment, micro holes are formed using a wet chemical etching method, which is inexpensive and can be mass processed. The shape of the holes depends on crystal facets, temperature, the concentration of the etchant solution, and etching time. We select a GaAs(100) single crystal wafer in this experiment and satisfactory results are obtained under the ratio of etchant solution with H2SO4:H2O2:H2O = 1:5:5. The morphology of micro holes according to the temperature and time is observed using field emission - scanning electron microscopy (FE-SEM). The etching mechanism at the corners and sidewalls is explained through the configuration of atoms.

주입구멍의 크기와 수관 상태에 따른 약액의 수간주입 속도를 알아보고자 주입구멍의 지름을 5mm와 10mm로 하고 수관을 온전, 절반 제거, 1/4씩 두 곳 제거 등 세 수준으로 구분하여 식용색소 적색3호 수용액을 수간주입하고 일정 시간별로 주입량을 측정하였다. 수간주입 4시간 뒤에 대부분의 느티나무에서 약액이 30% 이상 흡수된 상태였으며, 7시간 후에서는 7그루에서 모든 약액이 흡수된 것을 확인하였다. 48시간 후에는 처리 조건과 방법에 관계없이 한 그루를 제외한 모든 개체에서 주입액이 완전흡수되었다. 주입구멍의 크기나 수관의 상태 등은 수간주입 속도와 통계적 유의성이 없었다. 주간에서 움트는 잔가지의 잎들은 수간주입 후 24시간에 붉은색을 나타내기 시작하였으며, 48시간 후에는 수관의 잎들도 엽육조직이 붉게 변하여 수관도 붉은 색을 보였다. 수관이 변색된 나무의 수도 처리 내용 간에 통계적 유의차가 없었다. 줄기 단면 관찰에서도 주입구멍의 크기나 수관 상태 간에 적색주입액의 분포 차이가 없었다. 본 연구의 결과로부터 주입구멍의 크기나 수관의 엽량은 수간주입의 효율에 영향을 미치지 않음이 확인되었다. 따라서 큰 상처를 남기는 지름 10mm 주입구멍보다는 지름 5mm 주입구멍을 사용 하는 것이 나무의 자가치유를 도와주는 올바른 수간주입법이라고 할 수 있다.

Currently, due to the development of technology, the industry is proceeding with the development of advanced materials with high performance such as light weight, heat resistance and electric conductivity. Carbon Fiber Reinforced Plastics (CFRP) is an excellent material with high heat resistance, high strength and thermal shock resistance. In order to obtain excellent hole shape in CFRP drilling, we compared the modified drill shape and the conventional carbide drill. On the other hand, we determine the proper helix angle by observing the CFRP surface according to the helix angle at the trimming of the end mill proceeding after the hole machining.

The fracture of mechanical structure is caused by internal cracks in the material. Particularly, the fracture can also be seen to happen under the stress that is lower than yield strength in case of high strength steel because of the crack happening from the defect inside the material. In this study, high strength steel with four holes near the center crack were designed by angle and fatigue experiments, and the simulation analyses to verify the experimental results were carried out. As the results of this study, the crack growth rates are shown to be 0.000485, 0.000434 and 0.000422 respectively at the inclined angles of center crack as 22.5°, 45° and 67.5°. The maximum deformation energies become 0.0848mJ, 0.0603mJ and 0.0582mJ respectively at the inclined angles of center crack as 22.5°, 45° and 67.5°. It is thought that this study result can be utilized as the basic data at the study on the material existing with the defects of crack and hole.

Stress on plates may increase in the neighborhood the edges or the holes for rivets or bolts. Excessive stress concentration may lead to severe breakage of the plates. Thus, it is important to conduct optimization of arrangement of holes at the design stage. In this paper, accuracy of FEM analysis was examined for such stress concentration . By changing the hole size on a narrow plate, change of the stress concentration factor(K) was investigated. Additionally, the same experiment was conducted about series of multiple holes on plate to investigate interaction between the adjacent holes. Then, the FEM results were compared to the reference predictions respectively. Finally, a method by which simple stress concentrating situations can be optimized, will be suggested. This method was examined by FEM, and showed similar tendency with the expectation. Therefore, this method can be valuable when arranging the holes on a plate.

In this study, i machined micro hole to PCB(Printed circuit board) with ultra precision spindle system for mechanical micro drilling. For this i utilized 0.4∼0.6 ㎜ micro drill and observed cutting edge and hole. Results are as follows; in case of drilling with 0.4∼0.6 ㎜ micro drill, micro hole was made specific range of diameter up to 300 times drilling and micro drilled diameter was bigger than micro drill’s diameter at 300 times over. Error ratio of drilled diameter and damaged hole diameter was within 5 % and 17 %. I observed 0.4 ㎜and 0.6 ㎜micro drill’s cutting edge after 500 times drilling and confirm cutting edge width variation and damage, same result found 1000 times drilling with 0.5 ㎜ micro drill.

Separately from a single body, crash box is maufactured into the two alumnae by bonding adhesive. Crashbox has the property to absorb the shock by impact transferred to the car body at the collision between cars. In this study, the structural effect and performance are investigated according to the positions of holes punched at this crash box. The optimal structure is investigated for optimal design data of aluminum crash box. The equivalent stresses of study models distributed by compressive loads are compared with each other by using the analysis program of ANSYS. Total energies and mechanical strengths of study models at the real situation are also analyzed. As analysis results, the maximum equivalent stresses of 40880MPa, 42368MPa, 43176MPa, 44960MPa and 43476MPa are shown at study models due to the hole positions of 10mm, 15mm, 20mm, 25mm and 30mm from the upper plane of crash box respectively. Also, the total energy on analysis are verified within the error range of 10 % by comparing that on experiment at the hole position of 10mm. It is thought that the crash box due to the hole position from the upper plane of crash box can be effectively designed through this study result.

The residual stress analysis and fatigue test of a steel plate with a hole were performed in order to investigate the effects of the cold expansion on the fatigue life of the plate. The cold expansion method is a metal forming process by expanding a hole in order to induce compressive tangential residual stresses near the hole. In this research, a S45C steel plate of 3.2 mm thickness with a hole of 4.318 mm diameter was cold expanded by using a mandrel, resulting in a degree of expansion 1.47%. A significant amount of compressive tangential residual stress of 502 MPa at the hole surface was calculated using the finite element analysis and the compressive residual stress was more widely spreaded in the entry and exit planes than the mid plane in the plate thickness. The compressive tangential residual stresses showed a very beneficial influence on the fatigue life of the plate by increasing 1.2 to 2 times longer lives compared to the plate without cold expansion, depending on the applied load levels. Fatigue crack initiated and propagated at the hole surface of the mandrel entrance region, where relatively lower magnitude of compressive residual stress was found than the other region.

남한 미기록종인 Blepharhymenus koreanus Paśnik (호리바수염반날개) (신칭)과 Tachyusa wei Pace (배구멍바수염반날개)(신칭)을 처음으로 기록한다. 두 종에 대한 성충의 사진, 재기재 및 주요 형질에 대한 그림을 함께 제시한다.

The purpose of this study is to determine the possibility of using Agarum cribrosum as a natural health food source. To accomplish this purpose, the contents of the general and antioxidant activities of Agarum cribrosum were measured. The contents of carbohydrate, crude protein, crude lipid and ash were 45.4%, 15.0%, 2.3% and 33.1%. The calories of Agarum cribrosum were 262.3 kcal and total dietary fiber of Agarum cribrosum was 34.0%. The protein contained a total of 18 different kinds of amino acids. The content of amino acids was 12, 402.42 ㎎/100 g. The K was the largest mineral followed by Ca, Na and Mg, implying that Agarum cribrosum is an alkali material. The antioxidant activity of Agarum cribrosum was assessed by various radical scavenging assays using DPPH (2, 2-diphenyl-1 picrylhydrazyl), FRAP (ferric ion reducing antioxidant power), reducing power, and ABTS (2, 2'-azino-bis(3 ethylbenzothiazoline-6-sulphonic acid)). All antioxidant activity of Agarum cribrosum extract increased the concentration of the dependents. Total phenolic contents of Agarum cribrosum extract were 34.1±2.56 ㎎/g, and total flavonoids contents were estimated at 4.9±0.26 ㎎/g. General nutrients and other antioxidant bioactive materials in Agarum cribrosum were also potential materials for good health food. It is expected that a follow-up study of Agarum cribrosum through developing processed food and evaluation of their functional properties would provide useful information or sources of functional foods.

Small and medium companies have few dedicated employees for process planning and analyzing. They have many defects in their operational processes which result in less productivity. This research analyze a process of small company, which makes a hole and a round for gear parts. We found that the drilling operation is a bootle-neck operation and propose a revised general machine for drilling operation. The legacy drilling operation is performed as follows. First, a operator drills a half hole of a part and turns the part upside down. Then he drills a rest hole of the part. The operation needs more efforts than other operations. Therefore a productivity of the factory depends on that of the drilling operation. We developed a horizontal multi-drilling machine for the drilling operation. The machine has the drilling tool heads and takes three parts and makes a hole at the same time. It eliminates human operation in the middle of drilling, We also developed clamping jig for holding parts tightly. The proposed machine reduces the total operation time and enhances the productivity of the factory. The process capability index also increased from 6.8 to 9.6.

본 연구에서는 위상최적화 알고리즘의 수렴성을 개선하기 위해 설계영역에 초기 구멍을 도입하는 방법을 제시하는데, 이것은 경계면에 기초한 최적화 방법의 느린 수렴성을 완화하기 위해, Eschenauer et al.에 의해 고안된 버블 방법의 설계영역 안에 구멍을 도입하는 개념과 연계된다. 버블 방법과 달리, 제안된 방법에서는 최적화 과정동안 구멍의 위치를 정의하는 특성함수를 이용하지 않고, 최적화 초기화 단계에서만 초기 구멍을 도입하는데, 이러한 초기 설계영역 안의 솔리드와 보이드 영역들은 고정되는 것이 아니라 합쳐지거나 쪼개지면서 변화된다. 따라서 위상최적화 알고리즘에서 구멍의 이동에 관련된 복잡한 수치적인 계산 없이 자동적으로 설계변수의 유한변화를 더욱 강화시키기 때문에 목적함수 값의 수렴성을 개선할 수 있다. 본 논문에서는 다양한 치수와 형상의 구멍을 포함하는 초기 설계영역을 가지는 Michell형 보의 위상 최적설계를 밀도분포법으로 불리는 SIMP를 이용하여 수행하였다. 이를 통해 위상최적화의 수렴성을 개선하고 최적위상과 형상에 영향을 미치는 초기 구멍의 효과를 검증하였다.