• Journal of the Korean Society for Precision Engineering
• /
• v.14 no.11
• /
• pp.42-49
• /
• 1997

The extent of absorption and transmitance of the light that passes through some material is changed as the wavelength of the light varies, and which makdes it possible to estimate characteristics of the material. Spectrometer is a measurement system that can analyze the characteristics of material by using this principle. Its application field is so wide that it can be applied to all the arease that are concerned with analyzing materials : biological, environmental, medical and chemical area etc. This study is focused on developing precision sine drive mechanism for grating monochromator which is the most important part of the spectrometers. It is designed to be simple in struicture. It is achieved to derive basic principles to manipu- late precision sine drive mechanism : it should be aligned with a condition that .beta. , the angle between grat- ing normal and grating rod should be the same as .gamma. , the one between moving nut's normal and sliding guide. And also, it's found that the mis-alignments of the grating and mirrors are not the main factor in guaranteeing the linearity of sine drive mechanism. Performance evaluation is achieved by a standard sample by comparing experimental results with standard values. It results in wavelength accuracy of .+-. 0.5nm and resolution of 1nm. Conclusively, it can be verified that the sine drive mechanism developed in this study is not only simple in structure, but also stable and excellent in performanes.

• Horticultural Science & Technology
• /
• v.32 no.6
• /
• pp.788-793
• /
• 2014

Vegetative propagation of walnut is difficult compared with that of other fruit and nut species. The present study assessed three methods of grafting (patch, shield, and chip) at various periods of walnut growth and with different timings of grafting in walnut. Early May was the best time for grafting, at which time the highest success rate was obtained by the patch method (96%), followed by chip-budding (75%), while shield-grafting showed the lowest efficiency (10%). Patch-grafting was also successful (75-80%) in early August and moderately successful in mid-June (51-55%), while the shield and chip methods had no success during these two times (0.00%). Patch-grafting was more efficient and also induced better callus formation and scion growth than the other two methods. The genotypes used did not affect grafting efficiency. The best results were obtained by patch-budding in both tested genotypes. The present findings show the potential value of patch-grafting in early May as a propagation method for walnut for establishment of guidelines for propagation.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.10
• /
• pp.1355-1364
• /
• 2001

Characteristics of secondary vortices is topologically investigated in the near-wake region of a circular cylinder, where the Taylor's hypothesis does nut hold. The three-dimensional flow fields in the wake-transition regime were measured by a time-resolved PIV for various planes of view. The convection velocities of the Karman and secondary vortices are evaluated from the trajectory of the vortex center. Then, saddle points are determined by applying the critical point theory. It is shown that the inclination angle of the secondary vortices agrees well with the previous experimental data. The flow fields in a moving frame of reference have several critical points and the mushroom-like structure appears in the streamline patterns of the secondary vortices. Since the distributions of fluctuating Reynolds stresses defined by triple decomposition are closely related with the existence of secondary vortices, the physical meaning of them is explained in conjunction with the vortex center and saddle point trajectories.

• Journal of the Korean Society of Food Culture
• /
• v.20 no.2
• /
• pp.273-282
• /
• 2005

The purpose of this study was to nut a survey on the seasonal menu and consumer's acceptance test of free meals for the elderly facility in Sungnam Region. The elderly meals of the free lunch meal service were mainly composed of staple food, hot soup, and three kinds of side dishes. Questionare for accentance test was developed based on the seasonal menu including 13 kinds of cooked rices, 43 kinds of soups and 94 kinds of side dishes. The test was run for 104 elderly living and receving the service in the area. Average age of the subjects was 75.9 and 43% was male 57% was female. The 81% and 88% of the subject answered 'yes' on the intake of breakfast and dinner respectively representing high percentages of regular meal habits of the elderly. The cooked rice with black beans had significantly the highest acceptance score among the rice group and soups prepared with chunggukjang and cabbage had higher accentance scores(P<0.05). In the side dish groups, broiled eed, croakers, and various kinds of namuls had relatively higher scores than the others with significant difference at P<0.05.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.17 no.3
• /
• pp.35-44
• /
• 2009

The purpose of this paper is to describe experimental results about the T-joint welding of the high power continuous wave (CW) fiber laser for SAPH steel plate for seat frame of car. The seat rail is a part of seat frame of cars. The assembling method is mostly fix up using a bolt and nut. But this assembling method has many demerits in productivity such as increasing work process and material cost. This paper presents an experimental study about Laser T-Joint weldability of seat rail. Laser welding has many advantages in lightness and saving material costs of seat frame. The laser beam was moved along the work pieces by six axis robot with process optical fiber. The laser beam is focused with a welding head within incident angle $15{\sim}45^{\circ}$ for the purpose of the T-joint welding through two side full penetration. The range of the root gap size is less than ${\leq}0.4mm$. Optical microscopy SEM were performed to observe the micro structures and determine the structures of welded zone.

• Journal of the Korean institute of surface engineering
• /
• v.32 no.6
• /
• pp.647-657
• /
• 1999

Due to the inherently poor adhesion strength of Cu-based leadframe/EMC (Epoxy Molding Compound) interface, popcorn cracking of thin plastic packages frequently occurs during the solder reflow process. In the present work, in order to enhance the adhesion strength of Cu-based leadframe/EMC interface, black-oxide layer was formed on the leadframe surface by chemical oxidation of leadframe, and then oxidized leadframe sheets were molded with EMC and machined to form SDCB (Sandwiched Double-Cantilever Beam) and SBN (Sandwiched Brazil-Nut) specimens. SDCB and SBN specimens were designed to measure the adhesion strength between leadframe and EMC in terms of critical energy-release rate under quasi-Mode I ($G_{IC}$ ) and mixed Mode loading ($G_{C}$ /) conditions, respectively. Results showed that black-oxide treatment of Cu-based leadframe initially introduced pebble-like X$C_2$O crystals with smooth facets on its surface, and after the full growth of $Cu_2$O layer, acicular CuO crystals were formed atop of the $Cu_2$O layer. According to the result of SDCB test, $Cu_2$O crystals on the leadframe surface did not increase ($G_{IC}$), however, acicular CuO crystals on the $Cu_2$O layer enhanced $G_{IC}$ considerably. The main reason for the adhesion improvement seems to be associated with the adhesion of CuO to EMC by mechanical interlocking mechanism. On the other hand, as the Mode II component increased, $G_{C}$ was increased, and when the phase angle was -34$^{\circ}$, crack Kinking into EMC was occured.d.

• International Journal of Advanced Culture Technology
• /
• v.3 no.1
• /
• pp.179-187
• /
• 2015

This study presents the experimental results of the Friction Stir Welding (FSW) of AA6063 aluminum alloy and AISI304 stainless steel butt joint by varying the welding parameters such as the rotating speed and the welding speed. The main results are as follows. The variation of the welding parameters produced various characteristic interfaces and had distinct influences on the joint properties. Increasing the rotating speed and the welding speed decreased the joint tensile strength because it produced the defect on the joint interface. The optimum welding parameter that could produce the sound joint was a rotating speed of 750 rpm and the welding speed of 102 mm/min with the tensile strength of 71 MPa.

• International Journal of Advanced Culture Technology
• /
• v.3 no.1
• /
• pp.169-178
• /
• 2015

This research aims to study the effects of various welding parameters in gas metal arc welding (GMAW) process on welding penetration, microstructure and hardness of AS3578-A350 high strength steel with the thickness of 10 mm. The welding process parameters were a welding current of 100-200A, an arc voltage of 20-30V, a welding speed of 20-60 cm/min and a gas shielding type of Ar and $Ar+CO_2$. The summarized experimental results are as follows. An increase of the welding current and voltage affected to increase the penetration depth of the joint. However, when the welding speed was decreased, it increased the penetration depth of the joint. Using the Ar gas for shielding the weld area, produced the higher penetration depth and the less narrow weld bead than the joint that was shielded by the mix gas of $Ar+CO_2$. The variation of the welding process parameters affected to produce the various microstructures of weld metal and heat affected zone and also showed the various kind of hardness along the weld joint.

• Journal of the Society of Naval Architects of Korea
• /
• v.29 no.2
• /
• pp.123-131
• /
• 1992

In ship structural design procedures structural analyses are performed using the scantlings of structural elements determined at the initial design stage based on relevent rules and previous experiences. Modifications of scantlings will be carried out in case that the analysis results do nut satisfy design criteria. Reanalysis method s are efficient to analyse the structures of slightly modified using information obtained from the previous analysis. In this paper various approximate reanalysis techniques will be compared and their characteristics will be described. Furthermore sensitivity analyses are adapted to provide information from which selection of most influential design variables will be made and amount of modification can be determined. Redesign procedures described herein are demonstrated using examples.

• Journal of Sasang Constitutional Medicine
• /
• v.28 no.3
• /
• pp.205-214
• /
• 2016

Objectives This paper was aimed to review the preceding research on the origins, changes and constructive principle of Taeeumjowi-tang.Methods We reviewed Jema Lee's original works including Dongyisusebowon and relevant books to analyze Taeeumjowi-tang-related items. To compensate insufficient evidence of literature, we also refocued physiological and pathological pecularities of Taeeumin and relevant symptomatology.Results and Conclusions 1) The origins of Taeeumjowi-tang should be Mahwang-tang, Saengmaek-san, Seokchangpowonji-san, and Gondam-san. 2) Taeeumjowi-tang went through Saengmaek-san, Sanyakhwawi-jeon, Bopyesaengmaek-tang, Gilgyungsaengmaek-san, and Bopyewon-tang before it was built as the final version. 3) Taeeumjowi-tang consists of a) big blue lilyturf (麥門冬) and Omija (五味子) which are directly of help to exhale and disperse qi-fluid of Lung, b) balloon-flower (桔梗) which helps circulation of qi-fluid from Head to Lung, c) adlay (薏苡仁) and dry nut (乾栗) which are directly of help to raise up qi-fluid of Wiwan, d) ephedra (麻黃) which helps circulation of qi-fluid from Wiwan to skin, e) calamus (石菖蒲) which directly helps the psychological function of Ear, and f) radish seed (蘿葍子) which slightly eliminate the excessive function of Small intestine, treating Wiwanhan symptomatology in Taeeumin.