• Restorative Dentistry and Endodontics
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• v.25 no.1
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• pp.46-55
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• 2000

During bonding procedure of composite resin, the prepared cavity can be contaminated by saliva. In this study, marginal microleakage and shear bond strength of a composite resin to primed enamel and dentin treated with artificial saliva(Taliva$^{(R)}$) were evaluated. For the marginal microleakage test, Class V cavities were prepared in the buccal surfaces of fifty molars. The samples were randomly assigned into 5 groups with 10 samples in each group. Control group was applied with a bonding system (Scotchbond$^{TM}$ Multi-Purpose plus) according to manufacture's directions without saliva contamination. Experimental groups were divided into 4 groups and contaminated with artificial saliva for 30 seconds after priming: Experimental 1 group ; artificial saliva was dried with compressed air only, Experimental 2 group ; artificial saliva was rinsed and dried. Experimental 3 group ; cavities were etched with 35% phosphoric acid for 15 seconds after rinsing and drying artificial saliva. Experimental 4 group ; cavities were etched with 35% phosphoric acid for 15 seconds and primer was reapplied after rinsing and drying artificial saliva. All the cavities were applied a bonding agent and filled with a composite resin (Z-100$^{TM}$). Specimens were immersed in 0.5% basic fuschin dye for 24 hours and embedded in transparent acrylic resin and sectioned buccolingually with diamond wheel saw. Four sections were obtained from one specimen. Degree of marginal leakage was scored under stereomicroscope and their scores were averaged from four sections. The data were analyzed by Kruscal-Wallis test and Fisher's LSD. For the shear bond strength test, the buccal or occlusal surfaces of one hundred molar teeth were ground to expose enamel(n=50) or dentin(n=50) using diamond wheel saw and its surface was smoothed with Lapping and Polishing Machine(South Bay Technology Co., U.S.A.). Samples were divided into 5 groups. Treatment of saliva-contaminated enamel and dentin surfaces was same as the marginal microleakage test and composite resin was bonded via a gelatin capsule. All specimens were stored in distilled water for 48 hours. The shear bond strengths were measured by universal testing machine (AGS-1000 4D, Shimaduzu Co., Japan) with a crosshead speed of 5 mm/minute. Failure mode of fracture sites was examined under stereomicroscope. The data were analyzed by ANOVA and Tukey's studentized range test. The results of this study were as follows : 1. Enamel marginal microleakage showed no significant difference among groups. 2. Dentinal marginal microleakages of control, experimental 2 and 4 groups were lower than those of experimental 1 and 3 groups (p<0.05). 3. The shear bond strength to enamel was the highest value in control group (20.03${\pm}$4.47MPa) and the lowest value in experimental 1 group (13.28${\pm}$6.52MPa). There were significant differences between experimental 1 group and other groups (p<0.05). 4. The shear bond strength to dentin was higher in control group (17.87${\pm}$4.02MPa) and experimental 4 group (16.38${\pm}$3.23MPa) than in other groups, its value was low in experimental 1 group (3.95${\pm}$2.51 MPa) and experimental 2 group (6.72${\pm}$2.26MPa)(p<0.05). 5. Failure mode of fractured site on the enamel showed mostly adhesive failures in experimental 1 and 3 groups. 6. Failure mode of fractured site on the dentin did not show adhesive failures in control group, but showed mostly adhesive failure in experimental groups. As a summary of above results, if the primed tooth surface was contaminated with artificial saliva, primer should be reapplied after re-etching it.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.220-227
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• 2009

This study was conducted to select superior families based on the open-pollinated (OP) progeny tests of P. densiflora. A total of 232 OP families were analyzed for relative height growth. The OP progeny test trials were established at 1 to 4 sites from 1975 to 1987. To minimize temporal and spatial variation, we applied the standardization method for family selection. In each progeny test, superior and inferior families were selected at ages of 10, 20 and 30. Relative height growth rate (RHGR), growth speed at a given time unit, was comparatively high at age of 10 with range from 0.1 to 0.6 and showed a large variation among families. However, after age 15, the RHGR was low (average 0.04) and also the variation was not significantly different among families. To reduce selection errors due to age differences (from age 23 to 35) of tests, we made the family selection after age 15 when the values of RHGR were stable. Height growth at each age was transformed to be height growth at age 35 based on the RHGR. As the results, family CB2, CB3, KW99 and KW2 were selected as superior families and KW158, KW22, KB40 and GG1 were considered as inferior ones, respectively. Rank correlations (r) between test ages and selection age 35 were high and statistically significant; r = 0.881 between age 30 and 35, 0.653 between age 20 and 35, and -0.222 between age 10 and 35.

• Journal of Legislation Research
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• no.44
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• pp.757-799
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• 2013

Ever since Korea and Vietnam reestablished diplomatic relations, the two countries'bond has become stronger than ever, augmenting the range of exchange between them in almost every possible field including politics, economy, society, and culture at such a high speed. Among many, an increase in number of Vietnamese immigrant women in international marriage is worthy of close attention. Since 2010, Vietnamese has topped the proportion of total foreign women married to Korean men, having surpassed Chinese. Nonetheless, the quick international marriage between Korean men and Vietnamese women, which usually happens without sufficient time to get to know about different cultures and languages, has not only raised problems for people concerned, but numerous social issues as well. Recognizing these problems, a number of government departments have provided various support on policies and legal issues toprotect multicultural families as a means of social integration and settlement support. Nevertheless, the support policies until now have been generalizing all of the immigrant women in international marriage as people subject to protection. Thus, considering every immigrant women as people in need, and trying to help them with various social issues have caused the government a high cost and low efficiency. This thesis emphasizes the point that through the cases of Vietnamese immigrant women in international marriage, there should be a specific support plan for specific people in need, reflecting various traits of different cultures and societies, in order to ease their settlement in Korea. Moreover, it suggests detailed plans for improvements on legal and institutional problems. Although the Vietnamese government forbids commercial agents for international marriage, many of agencies are still active and to help the immigrant women, who desire to return and resettle in Vietnam in case of divorce, this thesis suggests legal and institutional remedies for Korean and Vietnamese government. The composition of the thesis follows below: Part II on social and cultural traits of international marriage between Korean men and Vietnamese women. Part III on institutional problems and plans for improvements regarding settlement of immigrant women in international marriage. Part IV on legal and institutional problems and plans for improvements regarding divorced immigrant women and their return to Vietnam. Part V on conclusion. Divorce is not a flaw anymore nowadays, but in case of Vietnamese immigrant women ininternational marriage, an inadequate legal system hampers their resettlement process. Cases of not being ableto remove their own names from the family register due to poor financial and legal abilities are often identified and it is both the Vietnamese and Korean governments'duty to acquit their ethical responsibilities by seeking ways to institutionally and financially support them.

• The Korean Journal of Archival Studies
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• no.15
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• pp.67-93
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• 2007

This article deals with the short history from 1999 to the present time, how the Korean record and archives management world had grown up, and what the development of the branch of records and archives studies resulted in. First of all, it is looked out upon the transition and feature of each initiative bodies of records management, containing the records producing body, records and archives management body, records and archives professional body, and civil society. As a result, this article points out the disequilibrium state of the records producing body and civil society, for all the growth of records and archives management institutions and records and archives professionals. During the time of establishing the law, the Korean records and archives management had been made a rapid progress by some part of the leading group being to Korean Records and Archives Service and the society of professionals. But it is estimated only the malformed development depending on the model of elites, although we could achieve the establishment of Korean Records and Archives Act. The condition of records and archives management of the Participation Government was distinguish from the state of former times, being driven up the renovation of records and archives management. The main power of the renovation was sought our by overcome of the elite model with the development of archival institutions and professionals extending wide range. Particularly professionals to accept the education of graduate school grew up in quantity and quality and then they let the pattern of the collaboration with archival institutions rake root in Korea. As The Road Map on the Renovation of National Records and Archives Management was made, the government put into practice, so the management of records and archives in Korea could take a step of steady and continuous growth. But the development of the records producing bodies and civil society is staying at the low level as yet. Accordingly it is expected to have the most important means that the professional instruction become to normalize and archivists who posted in public agencies after graduating professional education program discharge their duties. And each public agencies have to speed up to set up the institutions for records management including some archivists so that overcome the condition of underdevelopment as fast as possible.

• (The) Research of the performance art and culture
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• no.37
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• pp.157-186
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• 2018

Ulsan Soeburi song was reenacted in the 1980s based on the testimony and songs of late Choi Jae man (1987 death), the last blacksmith of the iron production plant at Dalcheon dong, Ulsan in August 1981. The purpose of this study is to analyze Soeburi song from the musical perspective based on 13 kinds of data including video in 1981, and confirm the changing patterns in the tradition process. The derived results are summarized as follows. In the results of examining Soeburi Song data in 2017, the percussion instruments consist of kkwaenggwari 2 (leading small gong 1, follow small gong 1), jing 2 (large gong 2), buk 4 (drum 4), janggu 4 (double headed drum 4), taepyongso 1 (Korean shawm 1), and Jangdan (rhythm) consists of five such as Jilgut, Jajinmori, Dadeuraegi, Deotbaegi, Jajin Deotbaegi. The vocal songs are sung accompanied by the Deotbaegi Jajin Deotbaegi (beat) of quarter small triplet time, or without accompaniment. The scale is mostly Mi La do's third note or Mi La do re's fourth note, and the range does not exceed one octave. All the cadence tones are the same as La. From the results of observing Soeburi song performance until today after the excavation in 1981, it is found that there are four major changes. First, the composition of the music is differentiated into 'long Jajin (slow fast)', and , , and are added. Second, the singing method is based on 'single cantor + multi post singers' since 1980's reenactment, and a single post singer was also specified from time to time. In addition, , which was performed in 2013, became the foundation of . Third, a melodic change of was observed. All beat structures are quarter small triplet time, but the speed gets slow, Mi La do's three notes are skeletonized to be corrected with high re and low sol, and then the characteristics of Menari tori (the mode appeared in the eastern province of the Korean peninsula) are to be clear. Lastly, the four percussion instruments such as kkwaenggwari, jing, janggu, and buk are frequently used, and depending on the performance, sogo (hand drum), taepyongso, yoryeong (bell) are also added. Jangdan played Jajinmori, Dadeuraegi, Deotbaegi and Jajin Deotbaegi from the beginning, and thereafter, the Jilgut Jangdan was added. Through these results as above, it is confirmed that at the time of the first excavation, a simple form of such as has been changed into a male labor song, the purpose of which has changed, and that the playability has become stronger and changed into a performing arts.

• Journal of the Korean earth science society
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• v.45 no.2
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• pp.121-135
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• 2024

This study examined the influence of near-surface atmospheric warming in the Arctic-East Asia region during spring (March-May) from 1991 to 2020 on the synoptic-scale meteorology of dust storm-induced dust days in Seoul, Korea, in response to the Arctic Oscillation. Increased springtime warming in the Arctic-East Asia region correlated with a reduction of six days in the occurrence of dust storm-induced dust days in Seoul, Korea, along with a decline in the intensity of these days by -1.6 ㎍ m^-3yr^-1 in PM₁₀ mass concentration. The declining number of dust storm-induced dust days in Korea during the 2010s was the result of synoptic-scale meteorological analysis, which showed increased high-pressure activity as indicated by the negative potential vorticity unit. Moreover, a distinct pattern emerged in the distribution of dust storm-induced dust days in Korea based on the Arctic Oscillation Index (AOI), showing an increase in negative AOI and a decrease in positive AOI. Although the northward shift of the polar jet weakened the southerly low-pressure system activity over Mongolia and northern China, a reinforced high-pressure system formed over the Chinese continent during dust-storm-induced dust days with a negative AOI. This resulted in both a decrease in the frequency of dust-storm-induced dust days and reduction in wind speeds, facilitating their transport from source regions to Korea. Conversely, on days with positive AOIs, an extensive warm and stagnant high-pressure system dominated mainland China, accompanied by further cooling of the northern segment of the polar jet. A notable decline in wind speed in the lower troposphere across the Mongolia-northern China-Korea region diminished the occurrence of dust storm-induced dust days and also weakened their long-range transport.

• The Korean Journal of Air & Space Law and Policy
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• v.32 no.1
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• pp.225-285
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• 2017

In regard to the regulations related to the RPA(Remotely Piloted Aircraft), which is sometimes called in other countries as UA(Unmanned Aircraft), ICAO stipulates the regulations in the 'RPAS manual (2015)' in detail based on the 'Chicago Convention' in 1944, and enacts provisions for the Rules of UAS or RPAS. Other contries stipulates them such as the Federal Airline Rules (14 CFR), Public Law (112-95) in the United States, the Air Transport Act, Air Transport Order, Air Transport Authorization Order (through revision in "Regulations to operating Rules on unmanned aerial System") based on EASA Regulation (EC) No.216/2008 in the case of unmanned aircaft under 150kg in Germany, and Civil Aviation Act (CAA 1998), Civil Aviation Act 101 (CASR Part 101) in Australia. Commonly, these laws exclude the model aircraft for leisure purpose and require pilots on the ground, not onboard aricraft, capable of controlling RPA. The laws also require that all managements necessary to operate RPA and pilots safely and efficiently under the structure of the unmanned aircraft system within the scope of the regulations. Each country classifies the RPA as an aircraft less than 25kg. Australia and Germany further break down the RPA at a lower weight. ICAO stipulates all general aviation operations, including commercial operation, in accordance with Annex 6 of the Chicago Convention, and it also applies to RPAs operations. However, passenger transportation using RPAs is excluded. If the operational scope of the RPAs includes the airspace of another country, the special permission of the relevant country shall be required 7 days before the flight date with detail flight plan submitted. In accordance with Federal Aviation Regulation 107 in the United States, a small non-leisure RPA may be operated within line-of-sight of a responsible navigator or observer during the day in the speed range up to 161 km/hr (87 knots) and to the height up to 122 m (400 ft) from surface or water. RPA must yield flight path to other aircraft, and is prohibited to load dangerous materials or to operate more than two RPAs at the same time. In Germany, the regulations on UAS except for leisure and sports provide duty to avoidance of airborne collisions and other provisions related to ground safety and individual privacy. Although commercial UAS of 5 kg or less can be freely operated without approval by relaxing the existing regulatory requirements, all the UAS regardless of the weight must be operated below an altitude of 100 meters with continuous monitoring and pilot control. Australia was the first country to regulate unmanned aircraft in 2001, and its regulations have impacts on the unmanned aircraft laws of ICAO, FAA, and EASA. In order to improve the utiliity of unmanned aircraft which is considered to be low risk, the regulation conditions were relaxed through the revision in 2016 by adding the concept "Excluded RPA". In the case of excluded RPA, it can be operated without special permission even for commercial purpose. Furthermore, disscussions on a new standard manual is being conducted for further flexibility of the current regulations.

• Clinical and Experimental Reproductive Medicine
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• v.2 no.2
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• pp.27-36
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• 1975

The success of the family planning program in Korea is reflected in the decrease in the growth rate from 3.0% in 1962 to 2.0% in 1971, and in the decrease in the fertility rate from 43/1,000 in 1960 to 29/1,000 in 1970. However, it would be erroneous to attribute these reductions entirely to the family planning program. Other socio-economic factors, such as the increasing age at marriage and the increasing use of induced abortions, definitely had an impact on the lowered growth and fertility rate. Despite the relative success of the program to data in meeting its goals, there is no room for complacency. Meeting the goal of a further reduction in the population growth rate to 1.3% by 1981 is a much more difficult task than any one faced in the past. Not only must fertility be lowered further, but the size of the target population itself will expand tremendously in the late seventies; due to the post-war baby boom of the 1950's reaching reproductive ages. Furthermore, it is doubtful that the age at marriage will continue to rise as in the past or that the incidence of induced abortion will continue to increase. Consequently, future reductions in fertility will be more dependent on the performance of the national family planning program, with less assistance from these non-program factors. This paper will describe various approaches to help to the solution of these current problems. 1. PRACTICE RATE IN FAMILY PLANNING In 1973, the attitude (approval) and knowledge rates were quite high; 94% and 98% respectively. But a large gap exists between that and the actual practice rate, which is only 3695. Two factors must be considered in attempting to close the KAP-gap. The first is to change social norms, which still favor a larger family, increasing the practice rate cannot be done very quickly. The second point to consider is that the family planning program has not yet reached all the eligible women. A 1973 study determineded that a large portion, 3096 in fact, of all eligible women do not want more children, but are not practicing family planning. Thus, future efforts to help close the KAP-gap must focus attention and services on this important large group of potential acceptors. 2. CONTINUATION RATES Dissatisfaction with the loop and pill has resulted in high discontinuation rates. For example, a 1973 survey revealed that within the first six months initial loop acceptance. nearly 50% were dropouts, and that within the first four months of inital pill acceptance. nearly 50% were dropouts. These discontinuation rates have risen over the past few years. The high rate of discontinuance obviously decreases the contraceptive effectiveness. and has resulted in many unwanted births which is directly related to the increase of induced abortions. In the future, the family planning program must emphasize the improved quality of initial and follow-up services. rather than more quantity, in order to insure higher continuation rates and thus more effective contraceptive protection. 3. INDUCED ABORTION As noted earlier. the use of induced abortions has been increase yearly. For example, in 1960, the average number of abortions was 0.6 abortions per women in the 15-44 age range. By 1970. that had increased to 2 abortions per women. In 1966. 13% of all women between 15-44 had experienced at least one abortion. By 1971, that figure jumped to 28%. In 1973 alone, the total number of abortions was 400,000. Besides the ever incre.sing number of induced abortions, another change has that those who use abortions have shifted since 1965 to include- not. only the middle class, but also rural and low-income women. In the future. in response to the demand for abortion services among rural and low-income w~men, the government must provide and support abortion services for these women as a part of the national family planning program. 4. TARGET SYSTIi:M Since 1962, the nationwide target system has been used to set a target for each method, and the target number of acceptors is then apportioned out to various sub-areas according to the number of eligible couples in each area. Because these targets are set without consideration for demographic factors, particular tastes, prejudices, and previous patterns of acceptance in the area, a high discontinuation rate for all methods and a high wastage rate for the oral pill and condom results. In the future. to alleviate these problems of the methodbased target system. an alternative. such as the weighted-credit system, should be adopted on a nation wide basis. In this system. each contraceptive method is. assigned a specific number of points based upon the couple-years of protection (CYP) provided by the method. and no specific targets for each method are given. 5. INCREASE OF STERILIZA.TION TARGET Two special projects. the hospital-based family planning program and the armed forces program, has greatly contributed to the increasing acceptance in female and male sterilization respectively. From January-September 1974, 28,773 sterilizations were performed. During the same time in 1975, 46,894 were performed; a 63% increase. If this trend continues, by the end of 1975. approximately 70,000 sterilizations will have been performed. Sterilization is a much better method than both the loop and pill, in terms of more effective contraceptive protection and the almost zero dropout rate. In the future, the. family planning program should continue to stress the special programs which make more sterilizations possible. In particular, it should seek to add the laparoscope techniques to facilitate female sterilization acceptance rates. 6. INCREASE NUMBER OF PRIVATE ACCEPTORS Among the current family planning users, approximately 1/3 are in the private sector and thus do not- require government subsidy. The number of private acceptors increases with increasing urbanization and economic growth. To speed this process, the government initiated the special hospital based family planning program which is utilized mostly by the private sector. However, in the future, to further hasten the increase of private acceptors, the government should encourage doctors in private practice to provide family planning services, and provide the contraceptive supplies. This way, those do utilize the private medical system will also be able to receive family planning services and pay for it. Another means of increasing the number of private acceptors, IS to greatly expand the commercial outlets for pills and condoms beyond the existing service points of drugstores, hospitals, and health centers. 7. IE&C PROGRAM The current preferred family size is nearly twice as high as needed to achieve a stable poplation. Also, a strong boy preference hinders a small family size as nearly all couples fuel they must have at least one or more sons. The IE&C program must, in the future, strive to emphasize the values of the small family and equality of the sexes. A second problem for the IE&C program to work. with in the: future is the large group of people who approves family planning, want no more children, but do not practice. The IE&C program must work to motivate these people to accept family planning And finally, for those who already practice, an IE&C program in the future must stress continuation of use. The IE&C campaign, to insure highest effectiveness, should be based on a detailed factor analysis of contraceptive discontinuance. In conclusion, Korea faces a serious unfavorable sociodemographic situation- in the future unless the population growth rate can be curtailed. And in the future, the decrease in fertility will depend solely on the family planning program, as the effect of other socio-economic factors has already been maximumally felt. A second serious factor to consider is the increasing number of eligible women due to the 1950's baby boom. Thus, to meet these challenges, the program target must be increased and the program must improve the effectiveness of its current activities and develop new programs.