Anomaly detection for each industrial machine is recognized as one of the essential techniques for machine condition monitoring and preventive maintenance. Anomaly detection of industrial machinery relies on various diagonal data from equipped sensors, such as temperature, pressure, electric current, vibration, and sound, to name a few. Among these data, sound data are easy to collect in the factory due to the relatively low installation cost of microphones to existing facilities. We develop a real time anomalous sound detection (ASD) system with the use of Autoencoder (AE) models in the industrial environments. The proposed processing pipeline makes use of the audio features extracted from the streaming audio signal captured by a single-channel microphone. The pipeline trains AE model by the collected normal sound. In real factory applications, the reconstruction error generated by the trained AE model with new input sound streaming is calculated to measure the degree of abnormality of the sound event. The sound is identified as anomalous if the reconstruction error exceeds the preset threshold. In our experiment on the CNC milling machining, the proposed system shows 0.9877 area under curve (AUC) score.

In this study, acoustic and viscosity data are collected in real time during the ball milling process and analyzed for correlation. After fast Fourier transformation (FFT) of the acoustic data, changes in the signals are observed as a function of the milling time. To analyze this quantitatively, the frequency band is divided into 1 kHz ranges to obtain an integral value. The integrated values in the 2–3 kHz range of the frequency band decrease linearly, confirming that they have a high correlation with changes in viscosity. The experiment is repeated four times to ensure the reproducibility of the data. The results of this study show that it is possible to estimate changes in slurry properties, such as viscosity and particle size, during the ball milling process using an acoustic signal.

In this study, we report the microstructure and characterization of Ta20Nb20V20W20Ti20 high-entropy alloy powders and sintered samples. The effects of milling time on the microstructure and mechanical properties were investigated in detail. Microstructure and structural characterization were performed by scanning electron microscopy and X-ray diffraction. The mechanical properties of the sintered samples were analyzed through a compressive test at room temperature with a strain rate of 1 × 10−4 s−1. The microstructure of sintered Ta20Nb20V20W20Ti20 high-entropy alloy is composed of a BCC phase and a TiO phase. A better combination of compressive strength and strain was achieved by using prealloyed Ta20Nb20V20W20Ti20 powder with low oxygen content. The results suggest that the oxide formed during the sintering process affects the mechanical properties of Ta20Nb20V20W20Ti20 high-entropy alloys, which are related to the interfacial stability between the BCC matrix and TiO phase.

Milled carbon fiber (mCF) was prepared by a ball milling process, and X-ray diffraction (XRD) diffractograms were obtained by a 2θ continuous scanning analysis to study mCF crystallinity as a function of milling time. The raw material for the mCF was polyacrylonitrile- based carbon fiber (T700). As the milling time increased, the mean particle size of the mCF consistently decreased, reaching 1.826 μm at a milling time of 18 h. The XRD analysis showed that, as the milling time increased, the fraction of the crystalline carbon decreased, while the fraction of the amorphous carbon increased. The (002) peak became asymmetric before and after milling as the left side of the peak showed an increasingly gentle slope. For analysis, the asymmetric (002) peak was deconvoluted into two peaks, less-developed crystalline carbon (LDCC) and more-developed crystalline carbon. In both peaks, Lc decreased and d002 increased, but no significant change was observed after 6 h of milling time. In addition, the fraction of LDCC increased. As the milling continued, the mCF became more amorphous, possibly due to damage to the crystal lattices by the milling.

In the present study, we investigate the effects of milling time and the addition of a process control agent (PCA) on the austenite stability of a nanocrystalline Fe-7%Mn alloy by XRD analysis and micrograph observation. Nanocrystalline Fe-7%Mn alloys samples are successfully fabricated by spark plasma sintering. The crystallite size of ball-milled powder and the volume fraction of austenite in the sintered sample are calculated using XRD analysis. Changes in the shape and structure of alloyed powder according to milling conditions are observed through FE-SEM. It is found that the crystallite size is reduced with increasing milling time and amount of PCA addition due to the variation in the balance between the cold-welding and fracturing processes. As a result, the austenite stability increased, resulting in an exceptionally high volume fraction of austenite retained at room temperature.

Y2O3–H3BO3:Eu3+ powders are synthesized using a mechanical alloying method, and their photoluminescence (PL) properties are investigated through luminescence spectrophotometry. For samples milled for 300 min, some Y2O3 peaks ([222], [440], and [622]) and amorphous formations are observed. The 300-min-milled mixture annealed at 800°C for 1 h with Eu = 8 mol% has the strongest PL intensity at every temperature increase of 100°C (increasing from 700 to 1200°C in 100°C increments). PL peaks of the powder mixture, as excited by a xenon discharge lamp (20 kW) at 240 nm, are detected at approximately 592 nm (orange light, 5Do → 7F1), 613 nm, 628 nm (red light, 5Do → 7F2), and 650 nm. The PL intensity of powder mixtures milled for 120 min is generally lower than that of powder mixtures milled for 300 min under the same conditions. PL peaks due to YBO3 and Y2O3 are observed for 300-min-milled Y2O3–H3BO3 with Eu = 8 mol% after annealing at 800°C for 1 h.

Titanium and its alloys are useful for implant materials. In this study, porous Ti-Nb-Zr biomaterials were successfully synthesized by powder metallurgy using a NH4HCO3 as space holder and TiH2 as foaming agent. Consolidation of powder was accomplished by spark plasma sintering process(SPS) at 850˚C under 30 MPa condition. The effect of high energy milling time on pore size and distribution in Ti-Nb-Zr alloys with space holder(NH4HCO3) was investigated by optical microscope(OM), scanning electron microscope(SEM) & energy dispersive spectroscopy(EDS) and X-ray diffraction(XRD). Microstructure observation revealed that, a lot of pores were uniformly distributed in the Ti-Nb-Zr alloys as size of about 30-100μm using mixed powder and milled powders. In addition, the pore ratio was found to be about 5-20% by image analysis, using an image analyzer(Image Pro Plus). Furthermore, the physical properties of specimens were improved with increasing milling time as results of hardness, relative density, compressive strength and Young's modulus. Particularly Young's modulus of the sintered alloy using 4h milled powder reached 52 GPa which is similar to bone elastic modulus.

In this study, the effect of milling time on the microstructure and phase transformation behaviors of Ni-12 wt.%B powders was investigated using vibratory ball milling process. X-ray diffraction patterns showed that the phase transformation of mixed Ni-B elemental powder occurred after 50 hours of milling, with a formation of nickel boride phases. Through the study of microstructures in mechanical alloying process, it was considered that ball milling strongly accelerates solid-state diffusions of the Ni and B atoms during mechanical alloying process. The results of X-ray photoelectron spectroscopy showed that most of B atoms in the powder were linked to Ni with a formation of nickel boride phases after 200 hours of milling. It was finally concluded that mechanical alloying using ball milling process is feasible to synthesize fine and uniform nickel boride powders.

In this research, the indium dissolution properties of the waste LCD panel powders were investigated as a function of milling time fabricated by high-energy ball milling (HEBM) process. The particle morphology of waste LCD panel powders changed from sharp and irregular shape of initial cullet to spherical shape with an increase in milling time. The particle size quickly decreased to 15 until the first minute, then decreased gradually about 6 with presence of agglomerated particles after 5 minutes, which increased gradually reaching a uniform size of 13 consist of agglomerated particles after 30 minutes. The glass recovery, after dissolution, was over 99% at initial cullet, which decreased to 90.1 and 78.6% with increasing milling time of 1 and 30 minute respectively, due to a loss in remaining powder of the surface ball and jar, as well as the filter paper. The dissolution amount of indium out of the initial cullet was 208 ppm before milling, turning into 223 ppm for the mechanically milled powder after 1 minute, and nearly 146~125 ppm with further increase in milling time because of the reaction surface decrease of powders due to agglomeration. With this process, maximum dissolving indium amount (223 ppm) could be achieved at a particle size of 15 with 1 minute of milling.

A composite of rapidly solidified Al-6061 alloy powder with graphite particle reinforcements was prepared by ball milling and subsequent hot extrusion. The microstructure and mechanical properties of these composites were investigated as a function of milling time. With increasing milling time, the gas atomized initially and spherical powders became elongated with a maximum aspect ratio after milling for 30 h. Then, refinement and spheroidization were achieved by further milling to 70 h with a homogeneous and fine dispersion of graphite particles forming between the matrix alloy layers. The best compression and wear properties were obtained in the powder milled for 70 h, associated with the increased fine and homogeneous distribution of graphite particles in the aluminum alloy matrix.

본 연구는 국내에서 재배되고 있는 조 품종의 도정수율 증진을 위한 도정방법 및 적정 수확시기를 검토한 결과를 요약하면 다음과 같다. 제현횟수와 도정시간에 따라 제현율과 완전미도정수율의 차이가 인정되었고, 이들의 상호작용에 있어서도 유의성이 인정되었다. 조의 완전미도정수율은 제현횟수를 2회, 도정시간을 1분 30초로 하였을 때 높았다. 출수 후 수확일수에 따른 현곡천립중, 제현율, 현곡의 경도, 도정율과 완전미도정수율의 차이가 인정되었고, 이들 요인간 상호작용에 있어서도 유의적인 상관이 인정되었다. 등숙율과 완전미도정수율 향상을 위해 조생종인 황금조는 출수 후 45일(적산온도 1,148℃ ), 중생종인 삼다메와 경관1호는 출수 후 50일(적산온도 1,150℃ ), 만생종인 삼다찰은 출수 후 55일(적산온도 1,168℃ )에 수확하는 것이 가장 적당하였다.

본 연구는 30개의 고품질 벼 품종을 공시하여 영남 남부 평야지에서 이앙시기의 차이가 도정특성에 미치는 영향을 살펴보고, 우리나라에서 재배되는 고품질 벼 품종 중에서 도정특성이 우수한 유전자원을 탐색하고자 수행하였으며, 그 결과는 다음과 같다. 1. 만기(6월 20일) 이앙시 보통기 이앙에 비하여(6월 5일) 출수가 6일 늦어지면서 등숙율과 백미 완전립비율, 완전미 도정수율이 증가하여 수당립수의 감소에 따른 쌀수량의 차이가 컸음에도 불구하고 완전미 쌀수량은 유의적인 차이가 없었다. 2. 현미 선별체를 이용한 현미립의 두께에 따른 분포특성은 보통기 이앙에 비하여 만기 이앙에서 1.6~1.9mm 두께의 현미립이 줄고, 1.9 mm 이상 두께의 현미립이 증가하여 균일도가 향상되었다. 3. 보통기와 만기 이앙간에 도정 손실율의 차이는 없었으나, 도정에 소요되는 시간이 만기 이앙에서 증가하였다. 4. 도정특성이 우수한 유망유전자원으로 남평벼, 일미벼, 추청벼, 동진벼, 호평, 말그미, 칠보, 히노히까리, 청무 등 9품종을 선정하였다. 5. 등숙율은 추청벼, 동진벼, 밀양 205호가 90% 이상으로 가장 양호 하였으며, 백미 완전립비율은 남평벼가 95%로서 가장 좋았고, 완전미 쌀수량은 남평벼와 일미벼가 500 kg/10a 이상으로 가장 높았다.

Power consumption, mesh size, moisture content, color difference, amylogram of rice flour milled with water soaked rice were compared with that of rice using dry pin mil process. Maximum water absorbance of rice was 35% for 2.5 hr. Power consumption to mill the soaked rice was less than of dry rice by 6.9kW/100Kg. Moisture content of rice flour from the water soaked rice was 2% higher than that of rice flour from dry rice. Population of flour particle was 52.9% of 60 mesh and 32.6% of 60∼80mesh. Gelatinization temperature of rice flour from the water soaked rice was 30C lower than that of rice flour from dry rice. Maximum and minimum viscosity of rice flour from the water soaked rice after boiling were 296 cps and 158 cps, independently. Brightness and whiteness of the rice flour from the water soaked rice were increased upto 10hr soaking and decreased after 17hr soaking. Brightness and whiteness of the rice flour were 96.17 and 96.02, independently.

인ㆍ일 원녹교잡에 의해 육성된 신품종들의 정곡수량과 외견상 품질면에서 최고수량을 얻을 수 있는 적정수확시기를 구명하여 미곡의 간접증산에 기여하고져 품종 수원26004와 밀양2003를 공시하고 출수후 25 일 이후 55 일까지의 기간에 곡립의 건물중, 수분함량, 만립성, 제현율, 도정율, 동할미율, 심복백미율, 청미율 및 수미율의 경시적 변화를 조사하였으며, 그 결과는 다음과 같이 요약된다. 1. 곡립건물중은 수원 26004의 경우 출수후 30일 경, 밀양2003의 경우 출수후 35일 경에 최대에 이르렀고(생리적 성숙기), 그 후 출수후 55일까지 유의차가 없었다. 2. 곡립수분함량(Y, %)은 출수후 일수(X)와 수원26004의 경우 출수후 34일까지는 Y=68.245-1.33X, 그 이후는 Y=23.025-0.470X의 관계를 나타냈고, 밀양2003의 경우 출수후 25일 경까지는 Y=73.62-1.634X, 그 이후는 Y=33.59-0.570X의 관계를 나타냈으며, 품종간에 출수기, 등숙기상 및 생리적 성숙기가 달랐으며 건조속도의 전환기가 달랐음에도 불구하고 생리적 성숙기의 곡립수분함량은 두 품종 모두 28%이었다. 3. 곡립의 탈립성은 인ㆍ일교잡품종 수원26004와 밀양2003, 일본형 품종 진흥 모두 출수후 35 일 경부터 50일까지 수확시기에 따른 차이는 작았고, 품종간 차이가 컸으며. 탈립성 품종은 입당 90～100g, 비탈입성 품종은 입당 200～250g 정도의 탈립 저항성을 나타냈다. 4. 제현율 및 도정률은 두 품종 모두 출수후 35일부터 55일간에 큰 차이를 보이지 않았고, 동할미율과 수미율도 차이가 없었으나 청미율과 심복백미율은 생리적 성숙기부터 10일간 뚜렷이 감소하였다. 5. 이상의 수확기와 정곡수량 탈립성, 미질의 상관에서 나타난 수확적기는 생리적 성숙기 10일후 경이며, 이 시기의 곡립수분함량은 20% 정도이었다.9.0～46.9% 였고, 지방은 18.0～22.1%, 17.1～22.5% 및 16.7～23.6% 였다. 6. 종실의 평균 단백질함량은 5월 25일, 6월 10 및 6월 25일 파종이 각각 41.9, 42.7 및 43.1%로 파종기가 늦어짐에 따라서 약간 증가하였고 품종별로는 서천백묘, 백천, SS-74185 및 강림 등이 높고 수원8003, 수원8006 및 Hill이 낮았으며 나머지 품종은 중정도였다. 한편 지방함량은 각각 19.8, 19.3 및 19.2%로 파종기간 차가 작았고 품종별로는 수원8003, 수원8006, 동북대, 봉의 및 Williams 등이 높고 서천백일, 강림, 백천, 륙우003, 동산6001, 동산 7003 및 성안 등이 비교적 낮았고 기타 품종은 중정도였으며, 대체로 단백질함량이 높았던 품종들이 지방함량이 낮은 경향이었다. 7. 단백질과 지방함량기간의 상관은 5월 25일 파종에서 고도의 부의 상관(r=-0.5914)이나 6월10일과 6월 25일 상관에서 각각 r=-0.3038과 -0.2975로 부의 상관경향만을 보여 파종기에 따란 상관의 정도가 약간 달랐다. 8. 10a당 종실수량은 6월10일 파종(100%)에 비해 5월 25일 파종에서 104%로 그 착 적었으나, 6월 25일 파종에서는 76%로 만파에 의한 감수정도가 컸다. 품종별 수량은 5월 25일 파종에서 동산7003, Hill 및 Williams, 6월 10일 파종에서 동산 6001, 동산 7003, Williams 및 Hill 등이 대비품종인 광교에 비해 유의증수하였고, 6월 25일 파종에서는 동산 7003만이 증수하였다. 조생종서천백묘, H-25)은 어느 파종기에서나 가장 낮은 수량이였다. 9. 만파(6월 25일 파종)에 의한 감수정도를 기준하여 내만식성정도를 분류하면 광교, 수원8003, 동산69호, 성안, H-25 및 Harosoy 등은 컸고 수원8006, 수원900