• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.10
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• pp.1550-1557
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• 2015

This study was conducted to evaluate the improvement effects of bitter taste of doraji (Platycodon grandiflorum) with different freezing temperature conditions ($-5^{\circ}C$, $-10^{\circ}C$, $-20^{\circ}C$, and $-70^{\circ}C$). After freezing for 4 h, frozen doraji was thawed and dehydrated. Doraji frozen at $-20^{\circ}C$ showed higher contents of crude fat, crude protein, crude ash, crude fiber, and nitrogen free extract. Moisture, crude saponin, and total polyphenol contents of doraji frozen at $-5^{\circ}C$ were higher than in other samples. Weight loss of doraji was significantly different as freezing temperature decreased and the process repeated. Doraji frozen at $-5^{\circ}C$ showed higher contents of saponin and phenol than the control. Hardness of doraji increased as freezing temperature decreased. According to the preference test, Doraji frozen at $-5^{\circ}C$ showed higher preference and less bitter taste intensity than other samples. These results mean that doraji frozen at $-5^{\circ}C$ with less bitter taste could be utilized widely as a food material.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.238-246
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• 1998

Surface residual stresses as well as wall thickness and ovality changes after U-bending process on UNS N06690 row-1 heat exchanger tubes, were estimated. Surface residual stresses were measured by Hole Drilling Method(HDM), calculating the stresses from relieved strains of 3 rosette strain gages. After bending of the tubes, dimensional tolerances for wall thickness and ovality were satisfied with ASTM requirements. Residual stresses at the extrados were introduced with compressive stress(-) by bending operations, and its maximum value reached-319 MPa in axial direction at ${\phi}=0^{\circ}$ in position. Tensile residual stresses(+) of ${\sigma}_zz=45$ MPa,${\sigma}_zz=25$ MPa were introduced in the intrados surface at position of ${\phi}=0^{\circ}$ Maximum tensile residual stress of 170 MPa was detected on the flank side at position of ,${\phi}=95^{\circ}$i.e., at apex region. It appeared that higher stress gradients were generated at the irregular transition regions. In the trend of residual stress changes with U-bend position, the extrados is related with the changes of ovality and the intrados is related with the changes of wall thickness.

• Journal of the Korean Vacuum Society
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• v.22 no.5
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• pp.262-269
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• 2013

Though focused ion beam (FIB) is one of the candidates to fabricate the nanoscale patterns, precision milling of nanoscale structures is not straightforward. Thus this poses challenges for novice FIB users. Optimal determination in FIB parameters is a crucial step to fabricate a desired nanoscale pattern. There are two main FIB parameters to consider, beam current (beam size) and dose (beam duration) for optimizing the milling condition. After fixing the dose, the proper beam current can be chosen considering both total milling time and resolution of the pattern. Then, using the chosen beam current, the metal nano hole structure can be perforated to the required depth by varying the dose. In this experiment, we found the adequate condition of $0.1nC/{\mu}m^2$ dose at 1 pA Ga ion beam current for 100 nm thickness perforation. With this condition, we perforated the periodic square array of elliptical nano holes.

• Journal of Korean Society of Steel Construction
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• v.27 no.1
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• pp.53-61
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• 2015

The tension type joint is a mechanically very efficient connection method, as it directly uses the load capacity of base metal or high tension bolt, the reduction of the number of drilling hole and fastening and the fatigue resistance. It is applied to the joint of girder and cross beam, horizontal joints of towers, beam to column joints, the secondary member joints of deck floor ends, and brackets. In this paper, static load tests for the T-type tension joint were conducted to investigate the structural behavior of the joint. The parameters were bolt diameter, flange thickness, and the reduction of clamping force of the joint. The failure modes and load capacity of joints and the effects of flange thickness, bolt diameter and clamping force were investigated.

• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.12
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• pp.1415-1420
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• 2014

3D printer is based on an additive manufacturing technology, which helps in creating the three-dimensional object using a 3D drawing. It is used in various fields, because it prints out a variety of three-dimensional products in a short period of time. In this paper, we consider a technique using the FDM(Fused Deposition Modeling) method by dissolving the ABS(Acrylonitrile Butadiene Styrene) resin among a diversity of printing technique and materials. This kind of the 3D printer prints out a product in high temperature and cools down it. In this process, a flection phenomenon is occurred according to the size of the printing product and the surrounding environment. Conventional methods for mitigating this phenomenon maintain the temperature at the optimum level, but they require using additional devices. In order to minimize the flection phenomenon in 3D printing products without additional devices, in this paper, we propose a noble technique, which creates holes on suitable positions when they are designed by 3D drawing tools. Also, we suggest mathematical model for the proposed method, and measure and analyse a printing output using a proposed technique.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.4
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• pp.386-392
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• 2009

This paper reports on the research which investigates acoustic signals acquired in progressive compressing, hole blanking, shearing and burr compacting process. The work piece is the head pin of the electric connector, whose raw material is the preformed steel bar. An acoustic sensor was set on the bed of hydraulic press. Because the acquired signals include the dynamic characteristics generated for all the processes, it is required to investigate signal characteristics corresponding to unit process. The corresponding dynamic characteristics to the respective process were first studied by analyzing the signals respectively acquired from compressing, blanking and compacting process. The combined signals were then periodically analyzed from the grinding to the grinding in the sound frequency domain and in the ultrasonic wave. The frequency of around 9 kHz in the sound frequency domain was much correlated to the tool wear. The characteristic frequency in the acoustic emission domain between 100 kHz and 500 kHz was not only clearly observed right after tool grinding but its amplitude was also related to the wear. The frequency amplitudes of 160 kHz and 320 kHz were big enough to be classified by the noise. The noise amplitudes are getting bigger, and their energy was much bigger as coming to the next regrinding. The signal analysis was based on the real time data and its frequency spectrum by Fourier Transform. As a result, the acousto-ultrasonic signals were much related to the tool wear progression.

• Journal of the Korean Society for Nondestructive Testing
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• v.13 no.3
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• pp.24-30
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• 1993

The necessity of ultrasonic inspection to detect the cracks in turbine blade is being increased as the forced outage of nuclear power plants have been occurred due to blade failure in turbine components. However, the complex blade root geometry causes the ultrasonic inspection technique not to be established yet and much effort is required to set up a more reliable inspection. In this paper, the ultrasonic inspection technique for flaw detectability, skew angle effect, identification of flaw and geometric signal have been investigated with a test block and discussed the interpretation of ultrasonic signal through the acquisition and analysis of RF waveform. The experimental results show that the proper examination procedure can be established. It is required that the skew angle is essential to decrease the effect of signals from the complex blade geometry. The present results of this study can be applied to the site inspection without blade disassembly.

• Journal of the Korean Wood Science and Technology
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• v.49 no.2
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• pp.154-168
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• 2021

Various types of wooden relics are being unearthed following the full-scale excavation in Wolseong palace site, Gyeongju in Korea. In particular, a large number of relics were found in the moat surrounding the Wolseong Fortress. This study attempted to secure basic data on the shields of the Silla era through species identification, radiocarbon dating, and shape analysis of the two wooden shields excavated from the Wolseong moat. As a result of the radiocarbon dating, it was confirmed that the shields were made of wood procured in the period between the mid-4th century and the early 5th century. The species identification confirmed that the body of the relic was made with Pinus soft pine group and the handle with Zelkova serrata. It was also confirmed that the excavated wooden shield was made by first marking a thin line on a flat grain board, then marking double concentric circles and perforating small holes. The distance between the division lines is constant at about 6cm, and spaces between them are colored in red and black. The shape analysis estimated that two artifacts were more than 50cm and 36cm in width, respectively.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10b
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• pp.247-252
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• 2007

오늘날 컴퓨팅 환경은 점차 복잡해지고 있으며, 복잡한 환경을 관리하는 이 점차 중요해 지고 있다. 이러한 관리를 위해 어플리케이션의 내부 구조를 드러내지 않은 상태에서 환경에 적응하는 자가치유에 관한 연구가 중요한 이슈가 되고 있다. 우리의 이전 연구에서는 자가 적응 모듈의 성능 향상을 위해 스위치를 사용하여 컴포넌트의 동작 유무를 결정하였다. 그러나 바이러스와 같은 외부 상황에 의해 자가 적응 모듈이 정상적으로 동작하지 않을 수 있으며 다수의 파일을 전송할 때 스위치가 꺼진 컴포넌트들은 메모리와 같은 리소스를 낭비한다. 본 연구에서는 이전 연구인 성능 개선 자가 적응 모듈에서 발생할 수 있는 문제점을 해결하기 위한 방법을 제안한다. 1) 컴포넌트의 동작 여부를 결정하는 스위치를 확인하여 비정상 상태인 컴포넌트를 찾아 치유를 하고, 2) 현재 단계에서 사용하지 않는 컴포넌트를 다른 작업에서 재사용한다. 이러한 제안 방법론을 통해 파일 전송이 않은 상황에서도 전체 컴포넌트의 수를 줄일 수 있으며 자가 적응 제어 모듈을 안정적으로 작동할 수 있도록 한다. 본 논문에서는 명가를 위하여 비디오 회의 시스템 내의 파일 전송 모듈에 제안 방법론을 적용하여 이전 연구의 모듈과 제안 방법론을 적용한 모듈이 미리 정한 상황들에서 정상적으로 적응할 수 있는지를 비교한다. 또한 파일 전송이 많은 상황에서 제안 방법론을 적용하였을 때 이전 연구 방법론과의 컴포넌트 수를 비교한다. 이를 통해 이전 연구의 자가 적응 모듈의 비정상 상태를 찾아낼 수 있었고, 둘 이상의 파일 전송이 이루어 질 때 컴포넌트의 재사용을 통해 리소스의 사용을 줄일 수 있었다.위해 잡음과 그림자 영역을 제거한다. 잡음과 그림자 영역을 제거하면 구멍이 발생하거나 실루엣이 손상되는 문제가 발생한다. 손상된 정보는 근접한 픽셀이 유사하지 않을 때 낮은 비용을 할당하는 에너지 함수의 스무드(smooth) 항에 의해 에지 정보를 기반으로 채워진다. 결론적으로 제안된 방법은 스무드 항과 대략적으로 설정된 데이터 항으로 구성된 에너지 함수를 그래프 컷으로 전역적으로 최소화함으로써 더욱 정확하게 목적이 되는 영역을 추출할 수 있다.능적으로 우수한 기호성, 즉석에서 먹을 수 있는 간편성, 장기저장에 의한 식품 산패, 오염 및 변패 미생물의 생육 등이 발생하지 않는 우수한 생선가공, 저장방법, 저가 생선류의 부가가치 상승 등 여러 유익한 결과를 얻을 수 있는 효과적인 가공방법을 증명하였다.의 평균섭취량에도 미치지 못하는 매우 저조한 영양상태를 보여 경제력, 육체적 활동 및 건강상태 등이 매우 열악한 이들 집단에 대한 질 좋은 영양서비스의 제공이 국가적 차원에서 시급히 재고되어야 할 것이다. 연구대상자 특히 배달급식 대상자의 경우 모집의 어려움으로 인해 적은 수의 연구대상자의 결과를 보고한 것은 본 연구의 제한점이라 할 수 있다 따라서 본 연구결과를 바탕으로 좀 더 많은 대상자를 대상으로 한 조사 연구가 계속 이루어져 가정배달급식 프로그램의 개선을 위한 유용한 자료로 축적되어야 할 것이다.상범주로 회복함을 알수 있었고 실험결과 항암제 투여후 3 일째 피판 형성한 군에서 피판치유가 늦어진 것으로 관찰되어 인체에서 항암 투여후 수술시기는 인체면역계가 회복하는 시기를 3주이상 경과후 적어도 4주째 수술시기를 정하는 것이 유리하리라 생각되

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.3
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• pp.167-174
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• 2023

This study investigated the microstructure and water absorption characteristics of the Korean adzuki bean (Vigna angularis L.) cultivar under accelerated storage. The germination rate, acid value, redness (a^*), and yellowness (b^*) values showed no significant differences after three months of storage compared to pre-storage under low temperatures (4℃). However, a statistically significant difference was observed under accelerated high temperatures (45℃). In particular, after storage for three months, the germination rate and acid value were 0% and 33.63 mg KOH/100g, respectively, under accelerated high temperatures. After storage for three months, the holes, hilum damage, and spaces between the seed coat and cotyledon shortened the time and speed of water absorption under accelerated high temperatures compared to that under low temperatures. Conversely, further research is required to investigate the reason for the low rate of parallel water absorption.