• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.2
• /
• pp.165-173
• /
• 2006

Purpose: With gold electroforming system fir the double crown, the secondary crown is electroformed directly onto the primary crown. An even thick layer of high precision can be acquired. It is thought that the retention of electroformed outer crown is primarily acquired by the adhesive force (surface tension) through the saliva which is interposed between precisely fitted inner and outer crown. The purpose of this study was to investigate the effect of taper and surface area of inner crown on the retentive force of electroformed outer crown according to the presence of saliva. Materials and methods: 32 titanium inner crowns with cervical diameter of 8 mm and cone angles of 0, 2, 4, 6 degrees, which had same surface area by regulated height, were machined on a lathe. Another 32 titanium inner crowns with cone angles of 0, 2, 4, 6 degrees, which had doubled surface area by increased cervical diameter. were fabricated. Eight specimens of each group, for a total of 64 titanium inner crowns, were prepared. The electroformed outer crowns were fabricated directly on the inner crowns by using electroforming machine(GAMMAT free, Gramm Technik, Germany). The tertiary frameworks were waxed-up on the electroformed outer crown and cast using nonprecious alloy($Rexillium^(R)III,\;Jeneric^(R)/Pentronh^(R)$ Inc., USA). The cast metal frameworks were sandblasted with alubimium oxides and cemented using resin cement(Superbond C&B, Sun Medical Co., Japan) over the electroformed copings of each specimen. Then, artificial saliva($Taliva^(R)$, Halim Pharm. Co., Korea) was sprayed between the inner and outer crown, and they were connected under 5 kg force. The retentive force was measured by the universal testing machine(Tinius Olsen 1000, Tinius Olsen, USA) with a cross-head speed of 66.67 mm/sec. The direction of cross-head travel was exactly aligned with the path of removal of the respective specimens. This measurement procedures for retentive force of electroformed outer crown with artificial saliva were repeated in the same way without presence of artificial saliva. Results and Conclusion: The following conclusions were drawn: 1. The retentive force of electroformed outer crown was decreased according to increased taper of inner crown(P<.05). 2. The retentive force of electroformed outer crown showed no significant differences according to surface area and the presence of artificial saliva(P>.05).

• Journal of Periodontal and Implant Science
• /
• v.37 no.4
• /
• pp.733-742
• /
• 2007

Bone morphogenetic proteins have been shown to possess significant osteoinSductive potential, but in order to take advantage of this effect for tissue engineering, carrier systems are essential. Successful carrier systems must enable vascular and cellular invasion, allowing BMP to act as a differentiation factor. The carrier should be reproducible, non-immunogenic, moldable, and space-providing, to define the contours of the resulting bone. The purpose of this study was to review available literature, in comparing various carriers of BMP on rat calvarial defect model. The following conclusions were deduced. 1. Bone regeneration of ACS/BMP, ${\beta}-TCP/BMP$, FFSS/BMP, $FFSS/{\beta}-TCP/BMP$, MBCP/BMP group were significantly greater than the control groups. 2. Bone density in the ACS/BMP group was greater than that in ${\beta}-TCP$, FFSS, $FFSS/{\beta}-TCP$ carrier group. 3. Bone regeneration in FFSS/BMP group was less than in ACS/BMP, ${\beta}-TCP/BMP$, MBCP/BMP group. However, New bone area of $FFSS/{\beta}-TCP/BMP$ carrier group were more greater than that of FFSS/BMP group. ACS, ${\beta}-TCP$, FFSS, $FFSS/{\beta}-TCP$, MBCP were used for carrier of BMP. However, an ideal carrier which was reproducible, non-immunogenic, moldable, and space-providing did not exist. Therefore, further investigation are required in developing a new carrier system.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.28 no.4
• /
• pp.683-693
• /
• 2001

The purpose of this study was to evaluate the effects of Er:YAG laser on cutting efficacy and its histologic findings. Dentin specimens of human premolars and molars were used and irradiated by Er:YAG laser with noncontact handpiece type delivery system under different treatment condition of irradiation time. Cavity pattern and volume were evaluated to determine the cutting efficacy and following results were obtained. 1. Cutting volume of sound dentin was getting larger with time immersed in water increase 2. With the condition of irradiation (150mJ, 10Hz, 30sec), surface irregularity was more increased in sound dentin comparing to carious dentin. For the light microscopic examination, dentinal tubules were opened and ash flecks and cracks were noted with inconsistence of dentinal tubules. 3. In case of 30 sec. irradiation in carious dentin, dark zone was limited to small focus whereas 1 min. irradiation, more wider, and cracks were noted in the perpendicular to direction of dentinal tubules. For the 2 min. irradiation, cavity was the widest and more cracks were found.

• Geophysics and Geophysical Exploration
• /
• v.18 no.4
• /
• pp.223-231
• /
• 2015

Self-potential (SP) is sensitive to groundwater flow and there are many causes to generate SP. Among many mechanisms of SP, pore-fluid flow in porous media can generate potential without any external current source, which is referred to as electrokinetic potential or streaming potential. When calculating SP responses on the surface due to geothermal fluid within an engineered geothermal system (EGS) reservoir, SP anomaly is usually considered to be generated by fluid injection or production within the reservoir. However, SP anomaly can also result from geothermal water fluid within EGS reservoirs experiencing temperature changes between injection and production wells. For more precise simulation of SP responses, we developed an algorithm being able to take account of SP anomalies produced by not only water injection and production but also the fluid of geothermal water, based on three-dimensional finite-element-method employing tetrahedron elements; the developed algorithm can simulate electrical potential responses by both point source and volume source. After verifying the developed algorithm, we assumed a simple geothermal reservoir model and analyzed SP responses caused by geothermal water injection and production. We are going to further analyze SP responses for geothermal water in the presence of water production and injection, considering temperature distribution and geothermal water flow in the following research.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.28 no.9
• /
• pp.343-349
• /
• 2016

Due to the recent increase in lighting energy consumption in buildings, there are a growing number of studies seeking solutions this problem. The effectiveness of light-shelves as natural lighting systems to solve this problem has been recognized, and various studies regarding such systems are being carried out currently. However, the lighting efficiency of light-shelves decreases if illumination intensity is low-such as at night time, and it also obstructs the views of building occupants. Therefore, the purpose of this study is to examine a movable drawer type light-shelf which allows for the width of the reflector to be adjusted and verify its performance through a simulated test-bed. The following conclusions were reached. 1) The purpose of this study is to solve the problem previously associated with the light-shelf system- of obstructed views-by responding to external environments and minimizing the width of the light-shelf at night time when the efficiency of the light-shelf declines. 2) The proper variables of the movable drawer type light-shelf which enables the width adjustment of the reflector were ascertained in this study according to four solar terms : a width of 0.6 m at an angle of $20^{\circ}$, a width of 0.4m with an angle of $20^{\circ}$, and a width of 0.1 m with an angle of $20^{\circ}$ were determined for the summer solstice, fall/spring equinoxes, and winter solstice respectively; revealing that width adjustment of the light-shelf is a significant factor. 3) The movable drawer type light-shelf which enables${\backslash}$width adjustment of the reflector suggested in this study can reduce the lighting energy consumption by 18.7% and 14.3% in comparison to previous light-shelves with a fixed width of 0.3 m and 0.6m, indicating that it is effective for saving energy.

• Journal of Ginseng Research
• /
• v.41 no.3
• /
• pp.339-346
• /
• 2017

Background: In this study, we investigated how to convert the Panax ginseng DNA sequence code and chemical fingerprints into a two-dimensional code. In order to improve the compression efficiency, GATC2Bytes and digital merger compression algorithms are proposed. Methods: HPLC chemical fingerprint data of 10 groups of P. ginseng from Northeast China and the internal transcribed spacer 2 (ITS2) sequence code as the DNA sequence code were ready for conversion. In order to convert such data into a two-dimensional code, the following six steps were performed: First, the chemical fingerprint characteristic data sets were obtained through the inflection filtering algorithm. Second, precompression processing of such data sets is undertaken. Third, precompression processing was undertaken with the P. ginseng DNA (ITS2) sequence codes. Fourth, the precompressed chemical fingerprint data and the DNA (ITS2) sequence code were combined in accordance with the set data format. Such combined data can be compressed by Zlib, an open source data compression algorithm. Finally, the compressed data generated a two-dimensional code called a quick response code (QR code). Results: Through the abovementioned converting process, it can be found that the number of bytes needed for storing P. ginseng chemical fingerprints and its DNA (ITS2) sequence code can be greatly reduced. After GTCA2Bytes algorithm processing, the ITS2 compression rate reaches 75% and the chemical fingerprint compression rate exceeds 99.65% via filtration and digital merger compression algorithm processing. Therefore, the overall compression ratio even exceeds 99.36%. The capacity of the formed QR code is around 0.5k, which can easily and successfully be read and identified by any smartphone. Conclusion: P. ginseng chemical fingerprints and its DNA (ITS2) sequence code can form a QR code after data processing, and therefore the QR code can be a perfect carrier of the authenticity and quality of P. ginseng information. This study provides a theoretical basis for the development of a quality traceability system of traditional Chinese medicine based on a two-dimensional code.

• The Korean Journal of Physiology
• /
• v.30 no.1
• /
• pp.33-41
• /
• 1996

The present study was aimed to investigate the role of endothelium-derived nitric oxide (NO) in the control of renin release and to examine if NO is implicated in the development of two-kidney, one clip (2K1C) hypertension. Male Sprague-Dawley rats $(150{\sim}200\; g)$ were constricted at the left renal artery. They were then supplemented with $N^{G}-nitro-L-arginine\;methyl\;ester\;(L-NAME,\; 5mg/100\;mL)$ or with L-arginine hydrochloride (400 mg/100 mL) in the drinking water. The control group was supplied with normal tap water. The sham-clipped rats were operated as in 2K1C rats except for that no clip was made. The kidneys were taken to examine in vitro release of renin at days 7 and 14 following clipping the renal artery. Northern blot analysis was also done to assess the expression of renin gene in the kidney. In sham-clipped rats, L-NAME caused a sustained increase of the blood pressure, whereas L-arginine was without effect. Neither L-NAME nor L-arginine-supplementation significantly affected the development of hypertension in 2K1C rats. Plasma renin concentration (PRC) measured on day 28 did not significantly differ among the L-NAME, L-arginine and control groups either in 2K1C or in sham-clipped rats. Renin contents (RRC) in the clipped kidney were increased, while those in the contralateral kidney were decreased. The release of renin in vitro from cortical slices was also enhanced in the clipped kidney, whereas it was attenuated in the contralateral. Comparing the RRC and in vitro release, the latter was more rapidly decreased than the former in the contralateral kidney. The renin mRNA levels in the contralateral kidney were almost at their nadir at days 7 and 14 in 2K1C rats. It is suggested that NO does not affect the development of 2K1C hypertension in which the renin-angiotensin system has been activated. The data also confirm that RRC and renin gene expression are increased in the clipped kidney and suppressed in the contralateral kidney in 2K1C rats.

• Korean Journal of Health Education and Promotion
• /
• v.19 no.3
• /
• pp.97-105
• /
• 2002

This study attempts to develop a program for obesity prevention and management for students in primary, middle, and high school and was carried based on the program development process as suggested by Ewles and Simnett. Data were collected from September 1st to September 30th, 2000. The study method is as follows: 1) Reviewing the present obesity control programs practiced in primary, middle, and high school (196 schools total) in metropolitan, medium-sized, and small cities, 2) Surveying obesity students'(682 students total) perception of the obesity management in their school. 3) Reviewing the annual plan for obesity in primary, middle, and high schools 4) Analyzing the educational data (CD, VIDEO) for obesity The results are as below: I. The media researched related to obesity were mainly CD and video, aimed primarily primary school students and are biased in nature. 2. The results of how to manage obesity in students: the difficulty of obesity education in the primary school, is the arousal of a sense of shame among obese students and the lack of various educational data are the most. In the middle and high schools, a lack of various educational data, and no time or lack of time were prevailing concerns. Paramount in managing obesity is weight control, as answered by majority of primary, middle, and high school students. The major problem of obesity management is the non-cooperation of children. 3. Asked whether the weight controlling aspect of health care class was helpful or not, 51.4% of primary school students, and 71.6% of middle and high school students answered not. The most popular educational method used in health care class is the computer, with a 56.4% approval rating. Most 43.5% of respondents answered that they wanted the content of obesity management program to focus on how to lose weight. Therefore, based on the results, the obesity management program is constructed to the steps of assessment, planning, implementation, and evaluation. Assessment includes administering surveys on health needs among students and their parents and physique tests. Planning includes the set-up of long term and short term educational goal and the establishment of an operation system. Implementation includes education, exercise, behavior modification, and health service programs. Evaluation includes step-by-step evaluations for obesity reduction. After this study is conducted, the following should be further researched: More practical and systematic obesity management programs should be developed for the evaluation results. In addition, it is important to develop an appropriate media for obesity management the primary, middle and high school students.

• Korea Journal of Hospital Management
• /
• v.7 no.4
• /
• pp.1-23
• /
• 2002

This study examined the influence of the separation of prescribing and dispensing roles(SPD) policy implemented in Korea in July 2000, especially on the change in the net profit of medical institutions. Using the data set from the Korea's National Health Insurance and the previous research, this study elicited the following main results. First, tertiary care institutions was estimated to lose about 631 billion won after the SPD policy. Second, general hospitals and hospitals gained about 557 billion and 564 billion won, respectively. Third, it is shown that clinics also gained 389-659 billion won. Finally, however, the change in net profit of medical institutions after the SPD policy largely depends on different estimation models. Moreover, it also varies from the assumptions on the price differential of a reimbursable drug which worked as cross-subsidy to insufficient physician's fee before the SPD policy. Despite such limitations as lack of data outside of the National Health Insurance's coverage, this study differs from others. This is the first research to explore the effect of the SPD policy on different types of medical institutions and to attempt to purely focus on the SPD policy. In this study, we can draw the policy implication that preparing for a policy change, the government should set up the policy evaluation system to collect the concerned data and develop the methodologies in advance to the policy implementation.

• Journal of Families and Better Life
• /
• v.28 no.6
• /
• pp.35-46
• /
• 2010

The purpose of the study was to identify the potential buyers' consciousness of single-family housing to provide useful data to help future single-family housing supplies in Ulsan. The study selected residents in Ulsan, who were over twenty and had an interest in living in a single-family housing. A survey was conducted from September 11, 2008 to September 25, 2008. The sample consisted of 364 persons who are currently live in Ulsan metropolitan area. The results are as following. About two thirds of the sample had the desire to live in a single-family housing. Moving into a single-family housing had financial preparation as the greatest issue. When moving into a single-family housing, the convenience of the residential district was the greatest consideration, whether or not it is a green environment, pollution level, etc. The potential buyers valued environment-friendly features and also had a very strong desire to own their own house. Many of them wanted to design and build their own single-family housing within a budget of 100-200 million KRW. In terms of the location, there was a higher preference for the riverside or lakeside rural areas outside the city. In terms of size, the preference was less than $330m^2$, which includes $99-132m^2$ for residential. When considering a single-family housing the direction was the most important feature, along with eco-friendly and safer materials and equipments. When building the single-family housing the potential buyers considered the community spaces first with a preference for having three bedrooms and two bathrooms. For the exterior, they wanted a unique shape of roof and there were high preferences for brown and beige colors. In terms of housing complexes, the potential buyers preferred individual unit types over complexes. If they preferred housing complexes, they wanted the cluster form complex with about 10-30 units. The complex also required a park-like setting with a guard system, which shows that convenience and safety were the most important features. In terms of complex management, they considered environmental management as the most important feature. The potential buyers were willing to pay belw 200,000 KRW, which showed their desire to minimize financial burdens.