• Journal of the Korean GEO-environmental Society
• /
• v.20 no.8
• /
• pp.5-12
• /
• 2019

A pile group, that consists of several piles connected by a pile cap, is used as the superstructure. The pile supports vertical and horizontal load to design the pile group, but the effect of bearing capacity of the pile cap has not considered. Various researches have been conducted to reflect the effect of bearing capacity of the pile cap in order to reduce the amount of piles in the range of the stability under the vertical load of the superstructure. However, the effect of bearing capacity under the horizontal seismic load has not been studied adequately. Therefore, a shaking table test was carried out with different-sized pile caps that support the superstructure in this study. This test was to verify the influence of the size of the pile cap in the group pile under the horizontal load. The result shows that the size of the pile cap affects to the dynamic behavior of the superstructure and the pile group. Also, the bigger size of the pile group makes the larger constraint effect of ground, and it results that both the ground and the pile moves as a whole.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2018.06a
• /
• pp.102-102
• /
• 2018

Electronic industry had required the finer size and the higher performance of the device. Therefore, 3-D die stacking technology such as TSV (through silicon via) and micro-bump had been used. Moreover, by the development of the 3-D die stacking technology, 3-D structure such as chip to chip (c2c) and chip to wafer (c2w) had become practicable. These technologies led to the appearance of HBM (high bandwidth memory). HBM was type of the memory, which is composed of several stacked layers of the memory chips. Each memory chips were connected by TSV and micro-bump. Thus, HBM had lower RC delay and higher performance of data processing than the conventional memory. Moreover, due to the development of the IT industry such as, AI (artificial intelligence), IOT (internet of things), and VR (virtual reality), the lower pitch size and the higher density were required to micro-electronics. Particularly, to obtain the fine pitch, some of the method such as copper pillar, nickel diffusion barrier, and tin-silver or tin-silver-copper based bump had been utillized. TCB (thermal compression bonding) and reflow process (thermal aging) were conventional method to bond between tin-silver or tin-silver-copper caps in the temperature range of 200 to 300 degrees. However, because of tin overflow which caused by higher operating temperature than melting point of Tin ($232^{\circ}C$), there would be the danger of bump bridge failure in fine-pitch bonding. Furthermore, regulating the phase of IMC (intermetallic compound) which was located between nickel diffusion barrier and bump, had a lot of problems. For example, an excess of kirkendall void which provides site of brittle fracture occurs at IMC layer after reflow process. The essential solution to reduce the difficulty of bump bonding process is copper to copper direct bonding below $300^{\circ}C$. In this study, in order to improve the problem of bump bonding process, copper to copper direct bonding was performed below $300^{\circ}C$. The driving force of bonding was the self-annealing properties of electrodeposited Cu with high defect density. The self-annealing property originated in high defect density and non-equilibrium grain boundaries at the triple junction. The electrodeposited Cu at high current density and low bath temperature was fabricated by electroplating on copper deposited silicon wafer. The copper-copper bonding experiments was conducted using thermal pressing machine. The condition of investigation such as thermal parameter and pressure parameter were varied to acquire proper bonded specimens. The bonded interface was characterized by SEM (scanning electron microscope) and OM (optical microscope). The density of grain boundary and defects were examined by TEM (transmission electron microscopy).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.593-601
• /
• 2021

The axial fan is an element of a blower used for ventilation in various industrial fields. Many studies on aerodynamic performance have been conducted to assess axial fans using fluid dynamics. The subject was a large axial fan size, 1800 mm in diameter with 100 horsepower. The blower's axial fan consisted of blades, hubs, hub caps, and bosses are important components. The blade design has a great influence on the aerodynamic performance. 3D point data is extracted using an aerodynamic performance prediction program, and a 3D modeling shape is generated. The blades and hubs, which are important components, can be easily modified if processed by cutting owing to the environment in which blades and hubs are manufactured through die casting or gravity casting. In this study, the structural safety of components and the analysis results of weak areas at the rated operating speed of the axial fan were verified using the maximum stress and safety factor. The tip clearance reflected in the design was the rotation of the blade. To check whether there is interference with other components, the displacement result was derived to verify the structural safety of the axial fan.

• Explosives and Blasting
• /
• v.9 no.1
• /
• pp.3-13
• /
• 1991

The cautious blasting works had been used with emulsion explosion electric M/S delay caps. Drill depth was from 3m to 6m with Crawler Drill ${\phi}70mm$ on the calcalious sand stone (soft -modelate -semi hard Rock). The total numbers of test blast were 88. Scale distance were induced 15.52-60.32. It was applied to propagation Law in blasting vibration as follows. Propagtion Law in Blasting Vibration $V=K(\frac{D}{W^b})^n$ were V : Peak partical velocity(cm/sec) D : Distance between explosion and recording sites(m) W : Maximum charge per delay-period of eight milliseconds or more (kg) K : Ground transmission constant, empirically determind on the Rocks, Explosive and drilling pattern ets. b : Charge exponents n : Reduced exponents where the quantity $\frac{D}{W^b}$ is known as the scale distance. Above equation is worked by the U.S Bureau of Mines to determine peak particle velocity. The propagation Law can be catagorized in three groups. Cubic root Scaling charge per delay Square root Scaling of charge per delay Site-specific Scaling of charge Per delay Plots of peak particle velocity versus distoance were made on log-log coordinates. The data are grouped by test and P.P.V. The linear grouping of the data permits their representation by an equation of the form ; $V=K(\frac{D}{W^{\frac{1}{3}})^{-n}$ The value of K(41 or 124) and n(1.41 or 1.66) were determined for each set of data by the method of least squores. Statistical tests showed that a common slope, n, could be used for all data of a given components. Charge and reduction exponents carried out by multiple regressional analysis. It's divided into under loom over loom distance because the frequency is verified by the distance from blast site. Empirical equation of cautious blasting vibration is as follows. Over 30m ------- under l00m ${\cdots\cdots\cdots}{\;}41(D/sqrt[2]{W})^{-1.41}{\;}{\cdots\cdots\cdots\cdots\cdots}{\;}A$ Over 100m ${\cdots\cdots\cdots\cdots\cdots}{\;}121(D/sqrt[3]{W})^{-1.66}{\;}{\cdots\cdots\cdots\cdots\cdots}{\;}B$ where ; V is peak particle velocity In cm / sec D is distance in m and W, maximLlm charge weight per day in kg K value on the above equation has to be more specified for further understaring about the effect of explosives, Rock strength. And Drilling pattern on the vibration levels, it is necessary to carry out more tests.

• Journal of Ginseng Research
• /
• v.44 no.1
• /
• pp.135-144
• /
• 2020

Background: Panax species are important herbal medicinal plants in the Araliaceae family. Recently, we reported the complete chloroplast genomes and 45S nuclear ribosomal DNA sequences from seven Panax species, two (P. quinquefolius and P. trifolius) from North America and five (P. ginseng, P. notoginseng, P. japonicus, P. vietnamensis, and P. stipuleanatus) from Asia. Methods: We conducted phylogenetic analysis of these chloroplast sequences with 12 other Araliaceae species and comprehensive comparative analysis among the seven Panax whole chloroplast genomes. Results: We identified 1,128 single nucleotide polymorphisms (SNP) in coding gene sequences, distributed among 72 of the 79 protein-coding genes in the chloroplast genomes of the seven Panax species. The other seven genes (including psaJ, psbN, rpl23, psbF, psbL, rps18, and rps7) were identical among the Panax species. We also discovered that 12 large chloroplast genome fragments were transferred into the mitochondrial genome based on sharing of more than 90% sequence similarity. The total size of transferred fragments was 60,331 bp, corresponding to approximately 38.6% of chloroplast genome. We developed 18 SNP markers from the chloroplast genic coding sequence regions that were not similar to regions in the mitochondrial genome. These markers included two or three species-specific markers for each species and can be used to authenticate all the seven Panax species from the others. Conclusion: The comparative analysis of chloroplast genomes from seven Panax species elucidated their genetic diversity and evolutionary relationships, and 18 species-specific markers were able to discriminate among these species, thereby furthering efforts to protect the ginseng industry from economically motivated adulteration.

• Journal of Fashion Business
• /
• v.3 no.1
• /
• pp.65-80
• /
• 1999

In this study, the researcher studied the historical background and the traditional culture about dress and ornament of Yunnan Province of China. The Results of the study are as follows. 1. In the Past, Derung's dress was very simple due to the influence of various factors, such as geography and history. Men wore shorts and covered diagonally a piece of cloth from left shoulders to right armpits and tied up the two ends on chests. Women covered crisscross two pieces of cloth from both shoulders to knee. 2. Achang people's dress and adornment has its own unique characteristic. Generally, men wear Jackets with buttons down the front and black trousers. Unmarried men like to wear white turbans, while most of married men usually wear dark blue ones. Women usually wear tight-sleeve blouses with buttons down the front and skirts. Unmarried women wear the hair in braids coil them on the top of their heads. They wear short blouses and trousers. Married women wear their hair Into buns and like to entwine black or blue cloth into high trubans. They wear short blouses and knee-length straight skirts. Achang knife enjoys high reputation and has a long history and an exquisite workmanship. All the men like to wear it. 3. The dress and adornment of the Lahu nationality has both the characteristic of farming culture and the style of nomadic culture of early times. Men usually wear short shirts with round necks and buttons down the front, loose-legged trousers, turbans or dark blue cloth caps Women's dress and adornment can be categorized into two styles. One is black cloth gown with buttons diagonally on the right front and waist-length slits on both sides. The edges of fronts and cuffs are edged with Silver ornaments and lace. They also wear trousers. The other is short blouse with round neck and short opening on th right front, straight skirt and colourful leggings with embroidered patterns. 4. The Hani people, men and women, old and young, like black colour and are fond of wearing black clothes. Men usually wear shirts with buttons down the front and trousers, entwining their heads with black or white cloth. The elderly people wear calottes. Women wear cloth blouses, skirts and trousers or shorts. Slight differences exist in the clothing and adornments according to region, branch and age 5. Blang people's dyeing technique with an exquisite method has a long history. Men wear dark blue long sleeve shirts with round necks and buttons down the front or arranged diagonally on the front and loose-legged trousers. Elderly men wear big turbans wdress and adornment varies greatly in different regions. 6. The Lisu people culture of dress and adornment has some unique characteristics. The styles and colours of their dress and adornment differ slightly from place to place. In the Nujiang area, Women wear black velvet Jackets over blouses with buttons arranged diagonally on the right front and long pleated ramie skirts. Men usually wear wraparound ramie gowns, with center vent, made of fabrics alternated with white and black cross stripes. They also wear cloth waistbands and trohile youngsters keep their hair short. Women's users. In the Lushui area, the dress and adornment is similar to that in the Nujing region, but women wear aprons and trousers instead of skirts. 7. The Nu people dress and adornment is simple but elegant Women are proficient in ramie-weaving. Men usually wear gowns With overlapping necks, knee-length trousers and leggings. They like to wear their hair long and entwine dark blue or white turbans. Women wear black and red vests over blouses with buttons arranged diagonally on the right front and ankle-length skirts. They also wear their hair long, make it into braids, and entwine dark blue or colourful cloth turbans. 8. Pumi men usually wear ramie shirts With buttons arranged diagonally on the right front, loose trousers and white sheepskin vests. Some also wear overcoats made of "pulu". Women's dress and adornment varies in different areas. In the Lanping and Weixi regions, women wear white short blouses with buttons arranged diagonally on the front and dark brown embroidered vests. They also wear trousers and blue or black cloth turbans. In the Ninglang and Yongsheng regions, women wear hemmed blouses With buttons arranged diagonally on the right front and drape sheepskin capes. They also wear white pleated skirts and use broad colourful cloth as their waistbands.