• 보건교육건강증진학회지
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• 제25권2호
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• pp.19-30
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• 2008

This study has comparatively analyzed the primary success factors in smoking cessation among new enrollees and re-enrollees of a smoking cessation clinic in order to find out how to efficiently operate smoking cessation clinics at public health centers. The study was conducted with 262,837 smokers aged 19 or over who were provided with smoking cessation services for more than 6 months after being registered with the smoking cessation clinic at public health centers(250 clinics nationwide) from July 16, 2006 to July 15, 2007. After dividing smokers into re-enrollees and new enrollees of the smoking cessation clinic, the success rate of and success factors for smoking cessation over 6 months have been investigated. The success factors in smoking cessation have been compared between new enrollees and re-enrollees of smoking cessation clinics. The results can be summarized as follows: First, the success rate of smoking cessation for 6 months at smoking cessation clinics of public health centers was higher in new enrollees (46.3%) than in re-enrollees (41.1%). Second, the common factors that had an influence on the success of smoking cessation of both new enrollees and re-enrollees of the smoking cessation clinic included age, social security, service, frequency of counseling, number of cigarettes per day, and alcoholic problems. Third, compared to new enrollees, re-enrollees had a higher success rate of smoking cessation as they got older. In terms of the success rate of health insurance, on the contrary, new enrollees were better than re-enrollees. Fourth, the study showed a higher success rate in smoking cessation in both new and re-enrollees if they had no alcoholic problems. In particular, a higher success rate was observed in re-enrollees when there were no alcoholic problems. To efficiently operate smoking cessation clinics at public health centers, this study confirmed that counseling should be tailored depending on the types of enrollees in the program.

• 한국산학기술학회논문지
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• 제16권6호
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• pp.3845-3857
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• 2015

본 연구는 고령화연구 패널조사(KLoSA)자료를 활용하여 중 노년층의 근로자의 재취업 의지와 재취업에 영향을 미치는 요인을 분석한 것이다. 분석은 독립변수를 개인적, 경제적 요인, 일자리의 세부분으로 나누어 로지스틱회귀분석에 의하였다. 분석결과 재취업의지는 대졸자보다는 고졸자가 더 높은데 비해 재취업 가능성은 더 낮게 나타났다. 이는 다른 연구와는 상반된 결과인데 고학력의 베이비부머가 대거 은퇴한 영향으로 보인다. 연령에서도 50대가 60대보다 재취업의지가 낮았다. 배우자 취업, 주택보유는 취업의지를 약화시키고, 일자리의 경우 근무기간과 사업장의 규모는 긍정적 영향을 미치나 산업의 종류나, 근로유형, 직종 등은 별 영향을 미치지 않은 것으로 나타났다. 중 노년층의 재취업 유도를 위해서는 자영업진출 억제, 변화된 고령자 노동시장에 적합한 일자리 창출, 비정규직 제도 개선, 최저임금제 현실화, 맞춤형 고용서비스 등이 필요하다고 보았다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.6116-6132
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• 2017

The proxy re-encryption allows an intermediate proxy to convert a ciphertext for Alice into a ciphertext for Bob without seeing the original message and leaking out relevant information. Unlike many prior identity based proxy re-encryption schemes which are based on the number theoretic assumptions such as large integer factorization and discrete logarithm problem. In this paper, we first propose a novel identity based proxy re-encryption scheme which is based on the hardness of standard Learning With Error(LWE) problem and is CPA secure in the standard model. This scheme can be reduced to the worst-case lattice hard problem that is able to resist attacks from quantum algorithm. The key step in our construction is that the challenger how to answer the private query under a known trapdoor matrix. Our scheme enjoys properties of the non-interactivity, unidirectionality, anonymous and so on. In this paper, we utilize primitives include G-trapdoor for lattice and sample algorithms to realize simple and efficient re-encryption.

• Parasites, Hosts and Diseases
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• 제37권3호
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• pp.129-143
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• 1999

Plasmodium vivax malaria, which was highly prevalent in the Republic of Korea, disappeared rapidly since 1970s. However, malaria re-emerged with the first occurrence of a patient in 1993 near the demilitarizd zone (DMZ), the border between South Korea and North Korea. Thereafter, the number of cases increased exponentially year after year, totaling 6,142 cases (6,249 if United States Army personnels were included) by the end of 1998. Interestingly enough, the majority of cases (3,743; 61%) was soldiers aged 20-25, camping around the northern parts of Kyonggi-do or Gangwon-do (Province) just facing the DMZ. Among 2.399 civilian cases, 1,144(47.%) were those who Provinces. The re-emerging malaria characteristically revealed a combination type of short and long incubation periods with predominance of the long type. The course of illness was relatively mild, and the treatment was successful in most patients. Vector mosquitoes are Anopheles sinensis and possibly A. yatsushiroensis. Wide-scale preventive and control measures should be operated to eradicate this re-emerging disease. It has been suggested by many authors that the initial source of the re-emerging malaria was infected mosquitoes which had flown from the northern part of the DMZ.

• 대한건축학회연합논문집
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• 제21권3호
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• pp.87-92
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• 2019

To relieve noise between floors in Korea, recent domestic and overseas studies have been developing materials that have the properties of ceramic, which is an inorganic compound, and polymer, which is an organic compound, to introduce a new function to polymer. This study conducted a bending strength experiment between re-bar and new composite concrete mixing POSS (Polyhedral Oligomeric Silses-quioxanes) nano complex on the inside of concrete, and by assembling the inside of each concrete with 3 and 4 main re-bars as an experiment to supplement various problems that occur by the expression of this strength and the distribution of the reinforcement. The number of the main re-bars. and the direction of laying the concrete were applied as the principal variables of the experiment. Upon experiment, there were no differences in the bond strength based on the location of the main re-bar, and a 2 % increase in the bond strength was shown in the specimen laid in the same direction as the main re-bar in comparison to that of the specimen laid in a different direction from the main re-bar. The experiment results displayed that the composite concrete had uniform performance based on the rapid reaction speed of POSS nano complex.

• 대한기계학회논문집B
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• 제28권1호
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• pp.118-125
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• 2004

The experimental study on flow and heat transfer characteristics was conducted to investigate and to compare the performance of swirl jet by a twisted tape as a swirl generator with the performance of impinging single circular jet in fully developed flow tube. The effects of jet Reynolds number(Re=8700, 13800, 20000, 26500), dimensionless distance of nozzle-to-plate(H/d=2, 4, 6, 8) and swirl ratio(S=0.11, 0.23, 0.30) of the jet on the local and average Nusselt number have been examined. Measurements of local heat transfer rate and flow patterns on the jet impinging plate were used naphthalene sublimation technique and flow visualization technique respectively. Mean velocity and turbulence intensity of the jet along the centerline were measured. With a twisted tape in the nozzle exit, average Nusselt number at the around area of stagnation point were higher than those without the twisted tape at H/d=2, 4 and with the increase of Reynolds number. With a twisted tape in the nozzle, in the case of H/d=2, Re=26500 and S=0.11, maximum local Nusselt number at the region of y/d=0 and x/d=0.44 was obtained.

• 한국전산유체공학회지
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• 제17권3호
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• pp.39-44
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• 2012

In this study, a longitudinal pitch effect on in-line tube bank heat transfer has been analyzed numerically. To verify the accuracy of the solver model and boundary conditions, global Nusselt number(Nu) and pressure drop across the 2 row tube bank are compared with the existing experimental correlations under 500 ~ 2,000 Reynolds number(Re) range. By changing transverse pitch($S_T$) or longitudinal pitch($S_L$) separately in tube bank, we're trying to identify the each effect on heat transfer. We found that the effect of transverse pitch can be accounted for Reynolds number evaluated with maximum velocity($V_{max}$) at the smallest flow area similar to most existing correlations. Variation of the longitudinal pitch($S_L$) has a greater impact on the heat transfer compared to the transverse pitch($S_T$). Overall Nusselt number increases with larger longitudinal pitch($S_L$), however individual Nusselt number of the tube row has significant difference after the first row.

• 대한기계학회논문집
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• 제18권6호
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• pp.1572-1581
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• 1994

Heat transfer characteristics in a rotating heat pipe with evaporator of the rotating disc and the condenser of the screwed groove is investigated by numerical method for various dimensionless film thicknesses, Re, C_{p}{\Delta}T/h_{fg}$, rotational speed and working fluids. The temperature difference between evaporator wall and vapor increases a little, but the temperature difference between condenser wall and vapor decreases rapidly as Re increases. As the dimensionless film thickness decreases, the temperature difference of evaporator and condenser decreases. As the rotational speed increases, the temperature difference between evaporator wall and vapor increases but the temperature difference between condenser wall and vapor decreases. The Nusselt number can be shown as a function of dimensionless film thickness and Re, that is $Nu=0.963\cdot(\delta^{-1}(\omega/\vpsilon)^{-1/2}{\cdot}Re^{0.5025})$.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 추계학술대회
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• pp.956-961
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• 2003

Direct numerical simulations of flow over a circular cylinder are performed at two different Reynolds numbers (Re=220 and 300) that correspond to three-dimensional instabilities of mode A and mode B, respectively, to investigate the characteristics of drag and lift at these Reynolds numbers. The drag and lift coefficients are measured locally along the spanwise direction and their characteristics are studied in detail. The variation of total drag in time is large at Re=220, and the total drag becomes minimum when vortex dislocation occurs in the wake. The drag and lift variations in space are also closely associated with the evolution of vortex dislocation at this Reynolds number. At Re=300, vortex dislocation is not found in the wake and temporal variations of drag and lift are much smaller than those at Re=220, but their spatial variations are quite large due to the near-wake secondary vortices existing in the mode B instability.

• 터널과지하공간
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• 제12권4호
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• pp.277-283
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• 2002

본 연구는 안쪽축이 회전하고 바깥쪽 실린더는 정지해있는 반경비가0.52이고 30$^{\circ}$ 경사진 동심 환형관내의 헬리컬 유동 특성에 관한 것이다. 비뉴튼 유체인 UC 수용액과 벤토나이트 수용액을 사용하여 안쪽축이 0~400pm으로 회전할 때 축방향 유동을 완전히 발달시킨 후 축방향 압력손실값을 측정하였다. 또한, 헬리컬 유동의 가시화는 불안정한 파를 관찰하기 위해 수행되었다. 현재 연구 결과는 표면마찰계수에 대해 로스비순(Ro)와 레이놀즈수(Re)의 관계를 나타내었다. 또한, 그 결과들은 유동 불안정성 메카니즘의 존재를 보인다. 축회전수가 증가함에 따라 압력손실이 증가하지만, 그 증가폭은 천이 및 난류영역에서는 레이놀즈수가 증가할수록 감소하며, 회전의 영향으로 유동교란이 증진되어 천이가 촉진된다. 또, 이런 유동교란의 증진은 표면마찰계수값의 증가와 함께 임계 레이놀즈수(Re$_{c}$)를 작게 만든다.