• Journal of the Korean Society for Precision Engineering
• /
• v.17 no.10
• /
• pp.192-199
• /
• 2000

The design of multi-stage gear drives is a time-consuming process because it includes more complicated problems, which are not considered in the design of single-stage gear drives. The designer has no determine the number of reduction stages and the gear ratios of each reduction stage. In addition, the design problems include not only dimensional design but also configuration design of gear drive elements. There is no definite rule or principle for these types of design problems. Thus the design practices largely depend on the sense and the experiences of the designer, and consequently result in undesirable design solution. A new and generalized design algorithm has been proposed to support the designer at the preliminary phase of the design of multi-stage gear drives. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. The algorithm consists of four steps. In the first step, the user determines the number of reduction stages. In the second step, gear ratios of every stage are chosen using the random search method. The values of the basic design parameters of a gear are chose in the third step by using the generate and test method. Then the values of the dimensions, such as pitch diameter, outer diameter and face width, are calculated for the configuration design in the next step. The strength and durability of each gear is guaranteed by the bending strength and the pitting resistance rating practices by using AGMA rating formulas. In the final step, the configuration design is carried out using simulated annealing algorithm. The positions of gears and shafts are determined to minimize the geometrical volume (size) of a gearbox while avoiding interferences between them. These steps are carried out iteratively until a desirable solution is acquired. The proposed design algorithm is applied to the preliminary design of four-stage gear drives in order to validate the availability. The design solution has considerably good results in both aspects of the dimensional and the configuration design.

• Journal of the Korean Geophysical Society
• /
• v.9 no.1
• /
• pp.47-62
• /
• 2006

More than 70% of Korean Peninsula is consisted of mountains, so that lots of roads, rail-roads and tunnel,which play a pivotal role in the industry activity, are existed along the rock-slope and in the rock-mass. Thus,it is urgent that tegration of management system through the optimum survey and design of rock-slope excavation, proper stabilization method and database of rock-slope. However, conventional methods have shortcoming with the economy of survey time and human resources, and the overcome of difficulties of approach to the in-situ rock-slope. To overcome the limitation of conventional method, this paper proposed the development of remote measurement system using Terrestrial Laser Scanning System. The method using Terrestrial 3D Laser Scanning System, which can get 3D spatial information on the rock-slope and2)Dept. Geosystem Engineering, Kangwon National University, Korea tunnel, has an advantage of reduction of measurement time and the overcome of difficulties of approach to the in-situ rock-slope/dam/tunnel. In the case of rock-slope, through the analysis of 3D modeling of point-cloud by Terrestrial Laser Scanning System, orientation of discontinuity, roughness of joint surface, failure shape and volume were successively achieved. in the case of tunnel face, through reverse-engineering, monitoring of displacement was possible.

• Journal of the Korea Concrete Institute
• /
• v.22 no.5
• /
• pp.719-725
• /
• 2010

The analysis and experimental program of reinforced concrete (RC) structures for resistance against such extreme loads as earthquake, blast, and impact have been carried by many researchers and designers. Under the extreme loads, a large amount of energy is suddenly exerted to the structure, hence if the structure fails to absorb the impact energy, catastrophic collapse may occur. To prevent catastrophic collapse of structures, reinforced concrete must have adeguate toughness or it needs to be strengthened. The FRP strengthening method and SFRC are studied widely in resistance of impact load because of their high energy absorption capacity. In this study, drop weight impact tests were implemented to evaluate the impact resistance of SFRC and FRP strengthened RC beam while the total steel fiber volume fractions was fixed at 0.75% carbon FRP flexural strengthened RC beams. Futhermore, to prevent the shear-plug cracks when the impact load strikes the beams, additional FRP shear strengthening method are applied. The experimental, results showed that the FRP strengthened RC SFRC beams has high resistance of shear-plug cracks and crack width and SFRC has high resistance of concrete spalling failure compared to normal RC beams. The FRP flexural and shear strengthening RC beams has weakness in the spalling failure because the impact load concentrated the concrete face which is not strengthened with FRP sheets.

• Asian-Australasian Journal of Animal Sciences
• /
• v.19 no.12
• /
• pp.1755-1760
• /
• 2006

Studies were carried out at the National Institute of Animal Nutrition and Physiology, India to determine the effect of feeding chopped paddy straw (Oryza sativa) on the energy expenditure in crossbred cattle. Four crossbred cattle male, aged 5-6 years and weighing about 450 kg were used for this study. Three experimental trials, one each for the feeding of un-chopped paddy straw offered ad libitum (UCA), chopped paddy straw fed at restricted level (CR) and chopped paddy straw offered ad libitum (CA) were conducted. The quantity of un-chopped paddy straw consumed during UCA was assumed as the voluntary intake by the cattle and the same quantity was offered after chopping during CR. Each trial comprised of 21 d preliminary feeding period and 5 d of observation recording period. Expired gas was collected in Douglas bags using a face-mask and three-way valve at 6 hourly intervals i.e., at 09.30, 15.30, 21.30, and 03.30 h throughout the observation period. Expired gas and ambient air inspired by the animals were analyzed for the oxygen content through paramagnetic oxygen analyzer. Energy expenditure (EE) by the animals was calculated by determining the volume of oxygen consumed per minute (STP) and multiplying by 4.825. Paddy straw used in all the three trials contained (g/kg DM) 90.0 CP, 786 OM, 700 NDF, 489 ADF, 357 Cellulose and 60.0 ADL. Metabolizable energy (ME) was 6.9 MJ/kg DM. Dry matter intake (DMI) both in UCA and CR was about 6.8 kg, except that it was chopped in CR. Chopping has resulted in 32% improvement (9 kg) in DMI of CA as compared to that of UCA. Although ME intake was similar in UCA and CR (47.2 MJ/day), energy expenditure (EE) was higher in UCA (23.3 MJ) when compared to that of CR (19.5 MJ). The ME intake (63.3 MJ) as well as EE (27.1 MJ) was highest in CA. Energy expenditure when expressed as MJ/kg DMI was 3.48, 2.90 and 3.12; whereas as per cent of ME intake it was 50, 41 and 44 in UCA, CR and CA respectively. Our study has unequivocally confirmed that chopping of poor quality roughages like paddy straw has definite advantages not only in terms of improving the intake by decreasing the time taken for ingestion but also in reducing the energy cost of eating.

• Journal of The Korean Society of Inherited Metabolic disease
• /
• v.10 no.1
• /
• pp.59-66
• /
• 2010

Enzyme replacement of therapy (ERT) is one of the most promising therapeutic strategies for the treatment of lysosomal storage disorders. ERT is available in three types of Mucopolysaccharidosis (MPS): for MPS I (Aludrazyme$^{(R)}$), MPS II (Elaprase$^{(R)}$) and MPS VI (Naglazyme$^{(R)}$) patients who are over 5 years old. But recently, early diagnosis can be done by expert clinicians and even in prenatal case. We describe the case of ERT under 5 years old MPS patients. Up to June, 2010 in Samsung Medical Center, there are 6patients who were diagnosed as MPS and started ERT under 5 years old. 3 patients were MPS I, 3 patients were MPS II. 2 patient who was diagnosed as MPS I was female and others were male. Their age at diagnosis were 4 to 37month-old (4, 13, 16, 25, 27, 37 month-old) and they are now 9 to 60 month-old (9, 39, 32, 81, 60 month-old). The youngest patient was started ERT at 4 month-old and others were started at their 13 to 49 month-old (13, 29, 27, 28, 49 month-old). First manifested symptoms of patients were macrocephaly, kyphosis and coarse face appearance. Especially, in 2 of them, one was MPS I and the other was MPS II had elder brother with same disease. And the youngest one was diagnosed by the iduronate-2-sulfatase (IDS) gene analysis from chorionic villi sampling. His mother knew that she was a heterozygous carrier of IDS gene mutation because her younger brother died from MPS II. All of them confirmed as MPS by the enzyme assay in leukocytes and fibroblast skin culture. We started ERT with ${\alpha}$-L-iduronidase(Aldurazyme$^{(R)}$) to MPS I and did recombinant human iduronate-2-sulfatase (Elaprase$^{(R)}$) to MPS II patients as recommended dose as over 5 years old. But for MPS II patient who was 4 month old, we started ERT by recombinant human IDS (Elaprase$^{(R)}$) with reduced dose 0.1 mg/kg and increased dose every 2 weeks by 0.1mg/kg up to 0.5mg/kg IV infusion. During ERT, all patients had no adverse effects and the excretion of GAGs were decreased. We have evaluated other clinical symptoms such as liver/ spleen volume, heart function and neurologic evaluation. We describe a successful ERT to MPS I and MPS II patient under 5 years old without any adverse event. It indicates that ERT in young children are well tolerated and that it has several effects which may confer clinical benefits with long-term therapy.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.44 no.2
• /
• pp.161-170
• /
• 2018

Skin aging degree can be objectively measured using the instrumental analysis. The purpose of this study was to evaluate the anti-aging effects of a cream containing 8000 PPM of resveratryl triacetate (RTA) in the human skin test. Twenty female subjects were given test products twice a day for 8 weeks on the face, and wrinkles, sagging, elasticity, dermis denseness, moisture and brightness were measured every 4 weeks by instrument analysis. After 4 and 8 week-use of the test product, total wrinkle area decreased (5.12%, 4.86%), total wrinkle volume decreased (10.53%, 8.41%), sagging decreased (4.69%, 5.91%), elasticity increased (2.84%, 3.98%), dermis denseness increased (15.65%, 20.80%), water content increased (5.83%, 7.37%), lightness ($L^*$ value) increased (0.79%, 1.07%), and individual typology angle ($ITA^{\circ}$) increased (5.43%, 4.95%)compared with the baseline values before treatments, and all these changes were statistically significant (p < 0.05). No adverse skin reactions were observed in all participants during the study period. This study supports the anti-aging effects of the test product.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.45 no.4
• /
• pp.508-513
• /
• 2018

Tidal volume by sevoflurane in small amounts is stable due to the increase in the breathing rate. But alveolus ventilation decreases due to sevoflurane as the degree of sedation increases; this ultimately causes $PaCO_2$ to rise. The occurrence of suppression of breath increases the risk of severe hypoxia and hypercapnia in deeply sedated patients with disabilities. Sevoflurane inhalation anesthesia has a number of risks and may have unexpected problems with hemodynamic changes depending on the underlying state of the body. This study was conducted to examine the stability of internal acid-base system caused by respiratory depression occurring when patients with disabilities are induced by sevoflurane. Anesthetic induction was carried out by placing a mask on top of the patient's face and through voluntary breathing with 4 vol% of sevoflurane, 4 L/min of nitrous oxide, and 4 L/min of oxygen. After the patient's loss of consciousness and muscle relaxation, IV line was inserted by an expert and intravenous blood gas was analyzed by extracting blood from vein. In a deeply sedated state, the average amount of pH of the entire patients was measured as $7.36{\pm}0.06$. The average amount of $PvCO_2$ of the entire patients was measured as $48.8{\pm}8.50mmHg$. The average amount of $HCO_3{^-}$ of the entire patients was measured as $27.2{\pm}3.0mmol/L$. In conclusion, in dental treatment of patients with disabilities, the internal acid base response to inhalation sedation using sevoflurane is relatively stable.

• Culinary science and hospitality research
• /
• v.6 no.1
• /
• pp.57-78
• /
• 2000

In the 21st century the size of sales of food service business in Korea will be 30 trillion won which means Food service business in Koreas is a mega market, but it is only quantitative growth and might face the limit of growth. At the same time it is predicted that from the academic world Food service business will develop endlessly after IMF condition. Of course I hope so as a member of national. Al though I propose that quantitative side is important, qualitative side must not be disregarded the present and future customer is needs should be met because the 1st goal of company is to achieve a management goal and pursuit profit. The present situation requires a peculiar and specific strategy of its own which can not be followed by competing hotels so that value can be created and buying intention can be occurred after buying. Until now the goal of marketing campaign has been transacted marketing just for closing a transaction, but it must be related marketing which is seeking mutual interests of customer and company. The strategies to attain these goals are : 1) to change from products and service management-focused to customer management and relationship building-focused. 2) to establish a core strategy which needs to be changed from market occupancy of volume expansion to customer occupancy. 3) to change from one-way communication to two-way communication. 4) to change from large scale marketing by company dimension to small scale marketing by sections. If companies focus on core benefit and augmented service to be sought by customers and make every efforts to create a value customer occupancy will increase automatically, the reduction of marketing cost will be followed, and marketing efforts will be much more efficient. In introducing a new product it is still easier to diffuse through the existing customers, and also important market information can be obtained from customers using this close relationship. If this close relationship maintains well customers will say even a trivial inconvenience and complaint and propose an idea of new product. Kotler divides relationship marketing into 5 stages such as Basic, Reactive, Accountable, Proactive, and Partnership. From the 1st stage to the last stage customer management is absolutely important and also in management strategy. The last stage, Partnership can come into the stage which is actively participated in service development and problem solving by customers. so more loyal customers have more successful performance the company attain.

• Journal of Biosystems Engineering
• /
• v.41 no.4
• /
• pp.328-336
• /
• 2016

Purpose: The heat culture areas of greenhouses have been continuously increasing. In the face of international oil price fluctuations, development of energy saving technologies is becoming essential. To save energy, auxiliary heat source and thermal insulation technologies are being developed, but they lack cost-efficiency. The present study was conducted to save energy by developing a conceptually new semi-basement type greenhouse. Methods: A semi-basement type greenhouse, was designed and constructed in the form of a three quarter greenhouse as a basic structure, which is an advantageous structure to inflow sunlight. To evaluate the performance of the developed greenhouse, a similar structured general greenhouse was installed as a control plot, and heating tests were conducted under the same crop growth conditions. Results: Although shadows appeared during the winter in the semi-basement type greenhouse due to the underground drop, the results of crop growth tests indicated that there were no differences in crop growth and development between the semi-basement type greenhouse and the control greenhouse, indicating that the shadows did not affect the crop up to the height of the crop growing point. The amount of fuel used for heating from January to March was almost the same between the two greenhouses for tests. The heating load coefficients of the experimental greenhouses were calculated as $3.1kcal/m^2{\cdot}^{\circ}C{\cdot}h$ for the semi-basement type greenhouse and $2.9kcal/m^2{\cdot}^{\circ}C{\cdot}h$ for the control greenhouse. Since the value is lower than the double layer PE (polyethylene) film greenhouse value of $3.5kcal/m^2{\cdot}^{\circ}C{\cdot}h$ from a previous study, Tthe semi-basement type greenhouse seemed to have energy saving effects. Conclusions: The semi-basement type greenhouse could be operated with the same fuel consumption as general greenhouses, even though its underground portion resulted in a larger volume, indicating positive effects on energy saving and space utilization. It was identified that the heat losses could be reduced by installing a thermal curtain of multi-layered materials for heat insulation inside the greenhouse for the cultivation of horticultural products by installing thermal curtain of multi-layered materials for heat insulation inside the greenhouse, it was identified that the heat losses could be reduced.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
• /
• v.14 no.3
• /
• pp.235-243
• /
• 2016

In the near future, many countries, including the Republic of Korea, will face a significant increase in low level radioactive waste (LLW) from nuclear power plant decommissioning. The purpose of this paper is to look at blending as a method for enhancing disposal options for low-level radioactive waste from the decommissioning of nuclear reactors. The 2007 U.S. Nuclear Regulatory Commission strategic assessment of the status of the U.S. LLW program identified the need to move to a risk-informed and performance-based regulatory approach for managing LLW. The strategic assessment identified blending waste of varying radionuclide concentrations as a potential means of enhancing options for LLW disposal. The NRC's position is that concentration averaging or blending can be performed in a way that does not diminish the overall safety of LLW disposal. The revised regulatory requirements for blending LLW are presented in the revised NRC Branch Technical Position for Concentration Averaging and Encapsulation (CA BTP 2015). The changes to the CA BTP that are the most significant for NPP operation, maintenance and decommissioning are reviewed in this paper and a potential application is identified for decommissioning waste in Korea. By far the largest volume of LLW from NPPs will come from decommissioning rather than operation. The large volumes in decommissioning present an opportunity for significant gains in disposal efficiency from blending and concentration averaging. The application of concentration averaging waste from a reactor bio-shield is also presented.