• 대한기계학회논문집A
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• 제35권5호
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• pp.575-582
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• 2011

클리닝 블레이드는 레이저 프린터 토너 카트리지에 장착된 감광드럼 표면의 잔류 토너를 제거하는 우레탄 재질의 고무부품이다. 기존에는 고무 블레이드의 클리닝 성능과 수명에 대한 다양한 연구들이 수행되었으나, 본 연구에서는 클리닝 성능과 부품간의 간섭에 대한 구속조건들을 모두 만족하면서 클리닝 블레이드에 발생하는 최대응력을 최소화 하는 클리닝 블레이드의 형상최적설계를 수행하였다. 상용 PIDO 툴인 PIAnO 를 이용하여 클리닝 블레이드의 구조해석절차를 통합하고 자동화하였으며, 최적설계를 위해 PIAnO 에서 제공하는 실험계획법과 근사화기법, 최적화 알고리즘을 사용하였다. 최적설계 결과, 초기 모델 대비 최대응력을 32.6% 감소 시킬 수 있는 최적의 설계안을 도출하였으며, 이를 통해 본 연구에서 수행한 최적설계 방법의 유효성을 확인할 수 있었다.

• 한국염색가공학회지
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• 제28권2호
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• pp.70-76
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• 2016

Silver nanoparticles(AgNPs) were attached to wool fibers using glycidyltrimethylammonium chloride(GTAC), which is a type of quaternary ammonium salt. GTAC, which contains an epoxy functional group that, under high temperatures, generates a ring-opening reaction with wool fibers, which contain the amine group. Then, the AgNPs are attached to the surface of the GTAC-treated wool fibers by treatment with a silver colloidal solution. The process involves the following procedures: (1) The wool fibers are immersed in the GTAC solution, followed by pre-drying at $80^{\circ}C$ and curing at $180^{\circ}C$ to induce an alteration in the chemical structure; and (2) The wool fibers treated with GTAC are immersed in the silver colloid at $40^{\circ}C$ for 120 min to chemically induce a strong attachment of the AgNPs to the wool fibers. Scanning electron microscopy was used to analyze the influence of the concentrations of GTAC and the silver colloid, as well as the influence of the applied temperature of the silver colloid on the wool fibers, and the influence of the morphological changes in the wool fiber surfaces. As a result, the enhanced concentrations of GTAC and the silver colloid together with an elevated applied temperature of silver colloid have a tendency to increase in Ag atomic%.

• 한국사회복지학
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• 제41권
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• pp.119-146
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• 2000

The goals and strategies of welfare-to-work (WTW) policies have been sources of contentious political debate. In the United States, despite 20 years of welfare reform, there remain important differences of opinion regarding how best to design and deliver WTW programs. The proliferation of state and local WTW experiments has led to the identification of two ideal-types of WTW programs: the Labor Force Attachment and Human Capital Development models. Most of the recent policy debate about WTW in America has focused on the relative merits and performance of LFA and HCD. While the Primary goal of the LFA model is for welfare recipients to achieve a rapid transition into work, the HCD model seeks to improve the long-term employability of welfare dependents through education and skill development. LFA policies tend to be strongly outcome-oriented and generally can yield quick results. Their "any job is a good job" philosophy has proved attractive to policy-makers who are anxious to see concrete results in a short-term period. In contrast, the HCD policies do not simply dump welfare dependents at the bottom of the labor market, but aim to secure relatively stable and well-paid jobs. However, these strengths are offset by several practical weaknesses including high unit costs and long-term investment in human capital. In recent years, LFA policies have been increasingly favored by both policy officials and politicians in the United States. The introduction of Temporaray Assistance to Needy Families of 1996 has been accelerating the trend. What is going to happen to welfare recipients? This simple shift to the LFA model, however, will only see an alarming increase of working poor in a near future.

• 한국환경과학회지
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• 제18권10호
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• pp.1171-1179
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• 2009

The solitary ascidian, Halocynthia aurantium, which is commonly called the sea peach because of its coloration and general shape, is a valuable organism of benthic marine population in the northern region of the East Sea, Korea. It is seldom found at a depth of less than 10 meters and the sea peach is frequently observed in large populations between 20 and 100 meters. It appears to prefer attachment to vertical rocks faces and artificial cement blocks exposed to the currents. Mass mortality and reduction of resources in sea peach, H. aurantium, were occurred in the benthic area of the northern region of the East Sea because of the rapid fluctuation of environmental factors such as temperature and salinity due to mass rainfall in summer and going up north of a strong warm current in winter. Therefore, we examined the effects of temperature and salinity on embryonic development of fertilized eggs, tadpole larva to metamorphosis, and attachment to siphon development. Laboratory-raised larvae were studied using a two-factorial experimental design with four levels of temperature(8, 12, 16 and $20^{\circ}C$) and four levels of salinity(20, 25, 30 and 34 psu). The ascidian larvae of H. aurantium survived environmental conditions between temperature of $8{\sim}20^{\circ}C$ and salinity of 25~34 psu and exhibited positive growth at $8{\sim}16^{\circ}C$ and 30~34 psu. Fertilized eggs have not developed at lower salinity of 20 psu irrespective of temperature range tested and have showed an abnormal development at the salinity of 25 psu between higher temperatures of 20 and $24^{\circ}C$. This result suggests that temperature increase and salinity reduction depending on environmental fluctuation may have significant impacts on population variation of H. aurantium in the northern region of the East Sea.

• Journal of Biosystems Engineering
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• 제13권2호
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• pp.38-45
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• 1988

This study was intended to develop the system automatically controlling travel direction of combine by means of sensing paddy rows. The control system was composed of three detecting levers having different length, micro-switch, microcomputer and electro-hydraulic control system. Sensor and control system developed was tested to estimate optimum design values and its actual performance as installed in combine. The computer simulation and performance test at simulated and actual field were conducted to test for possibility of practical use. The results of the study arc summarized. as follows: 1. The travel traces of combine hiving the conventional sensor with 2 levers and the new sensor detecting the slope of paddy rows were compared through computer simulation. Turning frequency of combine having new sensor was fewer than that of conventional sensor, but the rate of turning for the combine with new sensor was much greater than that of conventional sensor. 2. As sensor was established behind the tip of divider, the sensor itself well followed paddy rows but the tip of divider did not, resulting in divider being deviated from paddy rows. It was analyzed that the sensor should be attached closer to the tip of divider to have a better performance of the control system. 3. The greater the length of sensor lever for given location of sensor attachment and combine forward speed, the higher sensitivity of turning in control system. Moreover, increasing combine speed resulted in a worse performance of control system following paddy rows. Consequently, it was necessary that an optimum length of sensor attachment and for the range of combine operational speed. 4. Field test of combine installed with the sensor and electro-hydraulic system developed in this study showed that it may be operated smoothly and well behaved to paddy rows to 4th gear of combine speed which was 59cm/s. Consequently. it was concluded that the combine with the guidance control system developed in this study may be successfully used for paddy combining.

• 한국광학회지
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• 제16권3호
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• pp.254-260
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• 2005

높은 재현성과 함께 효율적인 수동 정렬을 위하여 제안된 대형코어 단일모드 폴리머 광도파로를 이용하여 제작 가능한 폴리머 광도파로 소자인 가변 광감쇠기를 제안하고 삼차원 빔전파 방법을 이용하여 소자의 동작 특성을 파악하고 최적 구조를 설계하였다. 소자의 표면에 집적된 박막 전극 히터에서 발생하는 열로 인해 폴리머 광도파로에서 발생하는 굴절률 분포 변화를 수치해석적으로 구하였으며 이 결과를 이용하여 삼차원 빔전파 해석을 수행하였다. 대형코어 광도파로가 가지는 작은 굴절률 대비로 인해 효과적인 광감쇠 현상을 작은 온도 변화로부터 얻을 수 있음을 확인하였다. 일반 광도파로 VOA에서 섭씨 150도 이상의 온도 변화가 필요한 반면 대형 코아 광도파로 VOA는 섭씨 70도 정도의 온도 변화 만으로도 20 dB 이상의 감쇠를 얻을 수 있었다. 대형코아 광도파로가 가지는 장점인 높은 정렬오차 허용범위와 더불어 낮은 구동전압으로 동작하는 장점을 함께 가지는 가변 광감쇠기 설계를 완성하였다.

• 한국통신학회논문지
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• 제30권4A호
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• pp.345-349
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• 2005

본 논문에서는 PC에서 사용하고 있는 주변기기를 연결하기 위한 범용 인터페이스의 성능과 구조를 개선하기 위하여 ATA(AT Attachment Interface with Extension)의 성능 및 SCSI(Small Computer System Interface)의 지능적인 동작의 장점들을 결합한 확장된 ATA 인터페이스를 구현하였다. SCSI버스는 지능적인 동작을 수행하는 주변기기를 위한 버스로써 잘 정리된 명령체계와 안정된 하드웨어 구조를 갖는 우수한 버스이다. 그러나 가격이 ATA주변기기에 비하여 2배 이상 차이나기 때문에 경제적으로 부담을 갖는다. 반면에 ATA주변기기는 초기에는 저성능이었으나, 개선 후 속도 측면에서 SCSI에 근접하고 경제적 측면에서도 우수하다. 본 논문에서는 이와 같은 장점을 이용하여 경제적 특성과 성능을 모두 만족시킬 수 있는 개선된 인터페이스 구조를 제안하고 하드웨어로 구현하였다.

• 대한치과보철학회지
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• 제37권2호
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• pp.185-199
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• 1999

This study was peformed to investigate the distribution and magnitude of stress at supporting tissue of abutment teeth and residual ridge tissue with remaining unilateral posterior teeth. Four types of removable partial dentures that included clasp retained removable partial denture, attachment retained removable partial denture, telescopic removable partial denture, and swing-lock partial denture were designed, and strain gauge was used for stress analysis. Each prosthesis was subjected to simulated vertical and oblique load. The following conclusions were drawn from this study. 1. The clasp retained removable partial denture generally distributed simulated vertical force more evenly to the supporting structure. 2. The stress at buccal side of 1st premolar was the lowest in swing-lock partial denture and that was highest in attchment retained removable partial denture. The stress at lingual side of 1st premolar was the lowest in telescopic partial denture. 3. In clasp retained removable partial denture, stress was lower at load site and ridge crest at mid-line, but it was higher at 1st premolar area on vertical load. 4. In attachment removable partial denture, stresses at buccal side of 1st premolar. lingual side of 1st premolar on vertical load, and ridge crest at midline on oblique load were higher. 5. In telescopic removable partial denture, stress at lingual side of 1st premolar was the least in all removable partial dentures, but the stress at load site was higher. 6. In swing-lock removable partial denture, stress at buccal side of 1st premolar was the lowest, and stresses at load site and distal end of residual ridge crest were higher.

• Journal of Electrical Engineering and Technology
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• 제13권5호
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• pp.2059-2066
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• 2018

This study explored the feasibility of utilizing an SWCNT-coated fabric sensor for the development of a wearable motion sensing device. The extent of variation in electric resistance of the sensor material was evaluated by varying the fiber composition of the SWCNT-coated base fabrics, attachment methods, number of layers, and sensor width and length. 32 sensors were fabricated by employing different combinations of these variables. Using a custom-built experimental jig, the amount of voltage change in a fabric sensor as a function of the length was measured as the fabric sensors underwent loading-unloading test with induced strains of 30 %, 40 %, and 50 % at a frequency of 0.5 Hz. First-step analysis revealed the following: characteristics of the strain-voltage curves of the fabric sensors confirmed that 14 out of 32 sensors were evaluated as more suitable for measuring human joint movement, as they yield stable resistance values under tension-release conditions; furthermore, significantly stable resistance values were observed at each level of strain. Secondly, we analyzed the averaged maximum, minimum, and standard deviations at various strain levels. From this analysis, it was determined that the two-layer sensor structure and welding attachment method contributed to the improvement of sensing accuracy.

• 대한간호학회지
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• 제49권2호
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• pp.137-148
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• 2019

Purpose: This study aimed to investigate the effects of a reinforcement program for behavioral skills in postpartum care for couples with their first baby. Methods: The study used a non-equivalent control group and pretest-posttest design. It was conducted from January 14 to April 10, 2016 at a postpartum care center in D city. It analyzed 43 couples (22 in the experimental group and 21 in the control group.) For data analysis, descriptive statistics, test of homogeneity in pretest, independent t-tests, and repeated measures ANOVA were used. Results: For maternal fulfillment of postpartum care and postpartum fatigue, there was no significant difference in the interaction between group and time. In terms of parent-newborns attachment, the interaction between group and time showed a significant difference for mothers (F=13.63, p=.001) and fathers (F=6.51, p=.001). In marital intimacy, the interaction between group and time showed a significant difference for mothers (F=14.40, p<.001) and fathers (F=9.46, p=.004). In parenting stress, the interaction between group and time showed a significant difference for mothers (F=31.8, p<.001) and fathers (F=11.69, p=.001). A significant difference was found for the mothers' postpartum sleeping hours (F=0.14 p=.004). Conclusion: This program for behavioral skills in postpartum care, which is based on the information-motivation-behavioral skills model, improves postpartum care, parent-newborn attachment, marital intimacy, parenting stress, and maternal postpartum sleeping, by reinforcing behavioral skills required for postpartum care.