• Archives of Plastic Surgery
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• 제38권4호
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• pp.401-407
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• 2011

Purpose: A number of flap for nipple reconstruction have been well described in the literature. However, most of these techniques do not permit the reconstruction of a projecting nipple and all are hampered to some extent by long-term loss of nipple projection. The objective of this study is to evaluate the long-term result and clinical efficacy of nipple reconstruction using skate flap technique after breast reconstruction. Methods: A retrospective chart review was carried out on 23 patients who underwent 25 nipple reconstructions. In those patients with greater than 10 mm nipple projection, reconstruction with skate flap and full-thickness skin graft and/or tattooing was performed. Maintenance of nipple projection was then carefully assessed over one-year follow-up. The following factors were analyzed: type of breast reconstruction, type of areola reconstruction, followup period, decrease in nipple projection, complication, and whether secondary nipple reconstruction was necessary and/or performed. Results: Breast reconstructions were performed in 17 patients with free transverse rectus abdominis musculocutaneous flap, 3 patients with extended latissimus dorsi musculocutaneous flap, and 3 patients with expander and implant. The mean follow-up after nipple reconstruction was 17 months. Mean loss of projection were $17.0{\pm}13.99%$, $25.0{\pm}12.70%$, $30.0{\pm}12.57%$ and $30.8{\pm}12.49%$ at 3, 6, 9 months and over one year, respectively. The greatest decrease in projection was noted in the first 3 months following surgery. Conclusion: These results indicated that nipple reconstruction with skate flap showed about 70 percent of the projection achieved over one year postoperation. Therefore, the skate flap may be a reliable method of nipple reconstruction in those patients with greater than 10 mm nipple projection.

• Archives of Plastic Surgery
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• 제43권5호
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• pp.470-473
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• 2016

Nipple-areolar complex (NAC) reconstruction is the final step in the long journey of breast reconstruction for mastectomy patients. Successful NAC reconstruction depends on the use of appropriate surgical techniques that are simple and reliable. To date, numerous techniques have been used for nipple reconstruction, including contralateral nipple sharing and various local flaps. Recently, it has been common to utilize local flaps. However, the most common nipple reconstruction problem encountered with local flaps is the loss of nipple projection; there can be approximately 50% projection loss in reconstructed nipples over long-term follow-up. Several factors might contribute to nipple projection loss, and we tried to overcome these factors by performing nipple reconstructions using a boomerang flap technique, which is a modified C-V flap that utilizes the previous mastectomy scar to maintain long-term nipple projection.

• Communications for Statistical Applications and Methods
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• 제28권4호
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• pp.393-410
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• 2021

The Korean Long-Term Care Insurance (K-LTCI) provides financial support for long-term care service to people who need various types of assistance with daily activities. As the number of elderly people in Korea is expected to increase in the future, the demand for long-term care insurance would also increase over time. Projection of future expenditure on K-LTCI depends on the number of beneficiaries within the grading system of K-LTCI based on the test scores of applicants. This study investigated the suitability of mixture distributions to the model K-LTCI score distribution using recent empirical data on K-LTCI, provided by the National Health Insurance Service (NHIS). Based on the developed mixture models, the number of beneficiaries in each grade and its variability under the current grading system were estimated by simulation. It was observed that a mixture model is suitable for K-LTCI score distribution and may prove useful in devising a funding plan for K-LTCI benefit payment and investigating the effects of any possible revision in the K-LTCI grading system.

• 한국노년학
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• 제31권4호
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• pp.1047-1065
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• 2011

본 연구는 노인장기요양보험 대상자 및 등급 확대에 따른 대상자 규모와 소요 재정을 추계함으로써 제도의 안정적 발전 및 지속가능성을 제고하고, 향후 정책개발에 기초자료 제공을 목적으로 한다. 연구방법은 문헌조사와 독일, 일본 등 선험국의 대상자 확대 정책을 고찰하여 대상자 확대 전략을 수립하고, 국민건강보험공단의 노인장기요양보험 대상자 증가추이, 노인성 질환대상자 증가 추이 분석, 현행 등급별 대상자의 급여 현황을 파악하여 등급 확대에 따른 재정소요를 예측하였다. 구체적인 방법으로 대상자 및 4등급 확대를 위한 범위 또는 범주를 시나리오별로 구체화하고 세분화된 급여 수준을 분석하여 재정을 추계하였다. 분석결과 대상자는 2010년 31만명에서 2015년 최소 42만명, 최대 57만명이었고, 이에 따른 관리운영비를 제외한 재정은 2010년 2.5조에서 2015년 최소 3.6조, 최대 4.0조인 것으로 추계되었다. 결과적으로 4등급 확대 시기는 제도안정화와 선험국의 선례와 경험을 함께 고려할 때 도입 4년차인 2012년 또는 5년 차인 2013년이 적정할 것으로 보인다. 이로인한 재정은 확대 초기 약 3천억원에서 1조 4천억원이 급여수준에 따라 예측되고, 확대이후 4등급 인정자 및 필요 재정지출은 점차 줄어들 것으로 예측된다. 선험국의 예를 볼때 급격한 4등급 확대보다는 시설 및 인프라가 감당할 수 있고, 재정 부담이 가능한 범위 내에서 확대 규모를 도출하는 것이 바람직할 것으로 판단된다. 본 연구는 시의성 있는 연구를 제시하여 향후 정확한 대상자 확대 및 재정안정화를 추구하도록 방향성을 제시하였다.

• 한국수자원학회논문집
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• 제46권8호
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• pp.833-842
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• 2013

분위사상법(QM, Quantile Mapping)은GCM(Global Climate Model) 자료의 계통적 오차를 보정하여 보다 신뢰성 높은 자료로 재생성하기 위해 활용되고 있다. 이 기법은 사상(mapping)시키려는 대상(object) 자료의 통계분포모수가 정상적(stationarity)이라는 가정 하에 대상 자료의 누적확률분포(CDF, Cumulative Distribution Function)를 목표(target) CDF에 통계적으로 투영시키는 것이 일반적이다. 따라서 GCM에서 제공되는 미래 기후시나리오의 강우시계열과 같이 비정상성(non-stationarity)을 갖는 장기 시계열자료에 대한 적용에는 문제점을 보이고 있다. 본 연구에서는 비정상성을 갖는 장기시계열자료의 오차보정을 위해 통계분포모수에 경향성을 부여하는 비정상성 분위사상법(NSQM, Nonstationary Quantile Mapping)을 적용하였다. NSQM 적용을 위한 확률분포로 수문분야에서 광범위하게 쓰이고 있는Gamma 분포를 선정하였으며, 대상 시나리오는 CCCma (Canadian Centre for Climate modeling and analysis)에서 제공하고 있는 CGCM3.1/T63모형의 20C3M(reference scenario)과 SRES A2 시나리오(projection scenario)를 활용하였다. 한강유역 내 관측기간이 충분한 10개의 지상관측소로부터 강우량을 수집하였다. 또한 6월과 10월사이에 연 강수량의 65% 이상이 집중되는 한반도의 계절성을 반영하기 위해 홍수기(6~10월)와 비홍수기(11~5월)를 구분하였고, 기준기간(Baseline)은 1973~2000년, 전망기간(Projection)은 2011~2100년으로 구분하였다. 다양한 목표분포의 설정을 통하여 NSQM의 적용성을 평가하고자 하였으며, 전망기간은 FF시나리오(Foreseeable Future Scenario, 2011~2040년), MF시나리오(Mid-term Future Scenario, 2041~2070년), LF시나리오(Long-term Future Scenario, 2071~2100년)의 3개의 구간으로 설정하여 기준기간과 전망기간의 연평균 강우량에 대한 경향성분석을 실시하였다. 그 결과NSQM이 FF시나리오에서 330.1mm(25.2%), MF시나리오에서 564.5mm(43.1%), LF시나리오에서 634.3mm(48.5%)로 증가하는 전망결과를 나타내고 있었다. 정상성기법을 적용한 결과, 전망기간 중 전체적으로는 동일한 평균값을 갖는 목표통계모수를 사용한다고 하여도, 전망전반부에서 과다하고, 후반부에서 오히려 과소한 전망을 보여주고 있었다. 이러한 결과는 비정상성기법을 사용함으로써 상당부분 개선될 수 있음을 확인하였다.

• 한국경영과학회지
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• 제42권1호
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• pp.29-41
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• 2017

Korea is expected to become a super-aged society by 2050. Given an aging population and the increasing pressure for the early retirement, a sufficient social safety net for elderly population becomes important. The Korean government introduced public reverse mortgage program in 2007, which is a product for aging seniors and the elderly, The number of reverse mortgage subscribers has also steadily grown. The demand continues to grow, but the reverse mortgage over a long period of time is a highly uncertain and risky product in the position of guarantee or lending institution. Thus, suitable demand prediction of the reverse mortgage subscribers is necessary for stable and sustainable operation. This study uses a Bass diffusion model to forecast the long-term demand for reverse mortgage and provides insight into reverse mortgage by forecasting demand for stability and substantiality of the loan product. We represent the projections of new subscribers on the basis of the data obtained from Korea Housing Finance Corporation. Results show that potential market size of Korean reverse mortgage reaches approximately 760,000-1,160,000 households by 2020. We validate the results by comparing the estimate of the cumulative number of subscribers with that found in literature.

• Archives of Plastic Surgery
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• 제41권2호
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• pp.158-162
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• 2014

Background Loss of nipple projection is a common problem following nipple reconstruction. The aim of this study was to demonstrate that the use of a tightly rolled dermal graft is effective in the long-term maintenance of nipple projection. Methods Nipple reconstruction was performed using the C-V flap technique. A dermal graft was harvested from the dog-ear portion of previous scars. The graft was rolled tightly into a compact cylinder and used to augment the nipple reconstruction. Postoperatively, stacked Allevyn dressing was used for protecting the nipple from compression for a minimum of two months. Nipple projection was measured at the time of surgery and at 12 months postoperatively. Results Forty nipple reconstructions were performed using this technique. There were 19 transverse rectus abdominis musculocutaneous (TRAM) flaps, 10 latissimus dorsi (LD) flaps, and 11 tissue-expanded breast mounds. At one year, the mean projection was 0.80 cm (range, 0.62-1.22 cm). The twelve-month average maintenance of nipple projection was 70.2% for the TRAM flap group, 76.3% for the LD flap group, and 61.8% for the tissue-expanded group. In two patients with previous irradiation of the reconstructed breasts, relatively poor maintenance of nipple projection was noted (45.7%). No complications were noted, and all of the donor sites healed well primarily. Conclusions Our results demonstrated that the use of a C-V flap with a tightly rolled dermal graft for nipple reconstruction improves the long-term maintenance of nipple projection. Its advantages include reproducibility, technical simplicity, cost-effectiveness, and minimal donor site morbidity.

• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1630-1643
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• 2023

The correct situation awareness (SA) of operators is important for managing nuclear power plants (NPPs), particularly in accident-related situations. Among the three levels of SA suggested by Ensley, Level 3 SA (i.e., projection of the future status of the situation) is challenging because of the complexity of NPPs as well as the uncertainty of accidents. Hence, several prediction methods using artificial intelligence techniques have been proposed to assist operators in accident prediction. However, these methods only predict short-term plant status (e.g., the status after a few minutes) and do not provide information regarding the uncertainty associated with the prediction. This paper proposes an algorithm that can predict the multivariate and long-term behavior of plant parameters for 2 h with 120 steps and provide the uncertainty of the prediction. The algorithm applies bidirectional long short-term memory and an attention mechanism, which enable the algorithm to predict the precise long-term trends of the parameters with high prediction accuracy. A conditional variational autoencoder was used to provide uncertainty information about the network prediction. The algorithm was trained, optimized, and validated using a compact nuclear simulator for a Westinghouse 900 MWe NPP.

• Animal cells and systems
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• 제2권1호
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• pp.65-69
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• 1998

The hippocampus and prefrontal cortex are regarded as the highest-order association cortices. The hippocampus has been proposed to store "cognitive maps" of external environments, and the prefrontal cortex is known to be involved in the planning of behavior, among other functions. Considering the prominent functional roles played by these structures, it is not surprising to find direct monosynaptic projections from the hippocampus to the prefrontal cortex. Rhythmic stimulation of this projection patterned after the hippocampal EEG theta rhythm induced stable long-term potentiation of field potentials in the prefrontal cortex. Comparison of behavioral correlates of hippocampal and prefrontal cortical neurons during an a-arm radial maze, working memory task shows a striking contrast. Hippocampal neurons exhibit clear place-specific firing patterns, whereas prefrontal cortical neurons do not show spatial selectivity, but are correlated to different stages of the behavioral task. These data lead to the hypothesis that the role of hippocampal projection to the prefrontal cortex is not to impose spatial representations upon prefrontal activity, but to provide a mechanism for learning the spatial context in which particular behaviors are appropriate.propriate.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2007년도 학술논문요약집
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• pp.63-64
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• 2007