Earticle

이 연구는 비편평화여과기(flattening filter-free, FFF) 빔을 이용한 폐 정위절제방사선치료(stereotactic ablative radiotherapy, SABR)에 대하여 서로 다른 선량계산 알고리즘의 선량적 효과를 조사하였다. SABR를 받은 10명의 폐암 환자를 대상으로하여 평가하였다. 모든 치료계획은 Eclipse 치료계획시스템의 Acuros XB (AXB) 알고리즘을 이용하여 수립되었다. 다른 선량계산 알고리즘과 비교를 위하여, 추가적으로 anisotropic analytic algorithm (AAA) 알고리즘을 적용한 치료계획을 재 수립하였다. 두 알고리즘 평가를 위해서, 치료표적과 손상위험장기의 선량체적히스토그램(dose-volume histogrim, DVH)를 분석하였다. 그리고 기술적 인자로써 계산시간과 총 MU 값을 평가하였다. DVH 비교분석을 통해, PTV의 최대선량은 AXB이 AAA 보다 5.2% 높았으며 최소선량은 4.4% 낮게 나타났다. PTV의 $V_{105%}$에서 7.06%까지 큰 차이를 나타났다. 폐의 최대선량은 AXB 치료계획에서 약간 크게 나타났다. 동측성 폐에 5, 10과 20 Gy 선량이 조사되는 체적은 AAA 보다 AXB에서 더 크게 나타났으나 대측성 폐에 대해서는 거의 비슷하게 나타났다. 척수와 심장에서 최대선량의 차이도 크지 않았다. 계산시간의 경우, AXB가 AAA보다 13.7% 정도 소요시간이 적었고 MU 값은 AXB에서 3.47% 더 많았다. 이 연구의 결과들은 회전조절치료 기법을 포함하여 FFF 빔이 적용된 폐 SABR 치료계획에서 AXB 알고리즘은 선량계산의 정확성과 계산시간의 감소의 장점을 제공할 수 있을 것이다.

This study investigated the dosimetric effects of different dose calculation algorithm for lung stereotactic ablative radiotherapy (SABR) using flattening filter-free (FFF) beams. A total of 10 patients with lung cancer who were treated with SABR were evaluated. All treatment plans were created using an Acuros XB (AXB) of an Eclipse treatment planning system. An additional plans for comparison of different alagorithm recalcuated with anisotropic analytic algorithm (AAA) algorithm. To address both algorithms, the cumulative dose-volume histogram (DVH) was analyzed for the planning target volume (PTV) and organs at risk (OARs). Technical parameters, such as the computation times and total monitor units (MUs), were also evaluated. A comparison analysis of DVHs from these plans revealed the PTV for AXB estimated a higher maximum dose (5.2%) and lower minimum dose (4.2%) than that of the AAA. The highest dose difference observed 7.06% for the PTV $V_{105%}$. The maximum dose to the lung was also slightly larger in the AXB plans. The percentate volumes of the ipsilateral lung ($V_5$, $V_{10}$, $V_{20}$) receiving 5, 10, and 20 Gy were also larger in AXB plans than for AAA plans. However, these parameters were comparable between both AAA and AXB plans for the contralateral lung. The differences of the maximum dose for the spinal cord and heart were also small. The computation time of AXB plans was 13.7% shorter than that of AAA plans. The average MUs were 3.47% larger for AXB plans than for AAA plans. The results of this study suggest that AXB algorithm can provide advantages such as accurate dose calculations and reduced computation time in lung SABR plan using FFF beams, especially for volumetric modulated arc therapy technique.

The process of producing high precision and light weight product is always exposed to impact load or shock. Because of this, isolator device is required. To measure the response of the isolator, accelerometer is practically used. However, the measured response of the accelerometer is different to the response of the isolator. To predict the response of the accelerometer and the isolator, 2-DOF damped system with an input shock is modeled using numerical analysis. 1-DOF damped system with a base excitation is also used to predict the response of the isolator. The mass ratio, damping ratio, and natural frequency ratio are then varied. The predicted responses from the two modeling approaches are compared and large errors are found.

4개월령의 수컷 잡종견이 교통사고에 의한 외상, 기립불능, 혼수, 복부통증으로 내원하였다. 방사선 검사에서 복수, 장 확장, 우측 장골 골절, 소심증이 확인되었다. 복부 초음파 검사에서 내강에 무 에코의 액체와 장벽 점막 내 가스를 함유하고 있는 심하게 확장된 소장 분절이 관찰되었다. 이러한 초음파적 특징은 장 기종 (pneumatosis intestinalis)에서 관찰되며, 이것은 외상에 따른 장 분절의 혈관 혈류 이상에 의한 것으로 의심된다. 환축이 폐사 한 후 부검한 결과, 일부 장 분절이 요추하 근육에 의해 교액되어 변색 및 괴사한 상태임을 확인하였다. 초음파는 장벽 내 에코가 있는 가스를 확인하여 장 기종을 진단할 수 있는 유용한 수단이다.

A 4-month-old, intact male mongrel dog was presented with trauma (hit by car), astasia, stupor and abdominal pain. Radiographic findings were peritoneal effusion, intestinal dilation, right iliac fracture, and microcardia. Abdominal ultrasonography revealed severely, dilated small intestine containing anechoic fluid in lumen and intramural gas within the wall. The sonographic finding suggested pnematosis intestinalis (PI), and vascular compromise of bowel loop by trauma was strongly suspected. After the dog was dead, postmortem examination revealed discolored and necrotized small intestine strangulated by sublumbar muscle. The detection of echogenic gas bubbles in the wall of bowel using ultrasound may be helpful in detecting PI.

This study used Chinese female college students as subjects to classify the components of the Korean national image as well as understand the recognition difference of country image factors and Korean fashion images; in addition, it examined the differences of the effect of Korean national image factors on the Korean fashion attitudes of Chinese female college students. A SPSS 18.0 statistic program with factor analysis, Cronbach's ${\alpha}$, paired t-test, multiple regression analysis, frequency analysis and ${\chi}^2$-test was used. The results are: First, it was shown that there are six factors: culture-society, economy, products, sports, politics, and technology. Second, the recognition difference on the six factors were significantly higher for products, politics, technology, economy, culture-society, and sports, respectively. Third, the difference of Korean fashion images showed that they recognize design uniqueness and diversity to choose styles preferentially. Fourth, the purchase intention was significant in the order of culture-society, products, politics, and sports, and recognition affects culture-society, sports, and products, respectively. Fifth, they prefer THE E-LAND GROUP, Beaucre Merchandising, and The Basic House the most and show a strong purchase intention. The analysis also showed that other various brands that are also recognized. These study results can provide Korean fashion companies with useful implications for marketing.

바이오매스 및 저등급 석탄인 갈탄은 잠재력이 큰 에너지원으로 이들을 가스화하여 합성가스를 얻으면 발전을 하거나 수송용 연료를 생산할 수 있다. 본 연구에서는 상압의 열천칭 반응기(thermobalance)에서 woodchip, 톱밥, 갈탄의 수증기 가스화반응의 kinetics를 조사하였다. 가스화 온도 $600{\sim}900^{\circ}C$, 수증기 분압 20~90 kPa 범위에서 수증기 가스화 반응을 수행하였다. 세 가지의 기체-고체 화학반응모델들이 가스화반응의 거동을 묘사하는 능력을 비교하였다. 이들 중에서 탄소전환율의 변화를 가장 잘 나타내는 modified volumetric model을 사용하여 가스화반응의 kinetic 정보를 도출하였다. Arrehenius plot으로부터 얻어진 시료들의 활성화에너지는 문헌상의 범위 내에서 얻어졌으며 톱밥 > woodchip > 갈탄의 순으로 나타났다. 각 시료에 대하여 수증기 분압에 대한 반응차수를 결정하였으며, 가스화공정 설계의 기초 데이터로서 겉보기 반응속도식을 제시하였다.

Biomass and low-grade coals are known to be better potential sources of energy compared to crude oil and natural gas since these materials are readily available and found to have large reserves, respectively. Gasification of these carbonaceous materials produced syngas for chemical synthesis and power generation. Woodchip, sawdust and lignite were gasified with steam in a thermobalance reactor under atmospheric pressure in order to evaluate their kinetic rate information. The effects of gasification temperature ($600{\sim}900^{\circ}C$) and partial pressure of steam (20~90 kPa) on the gasification rate were investigated. The three different types of gas-solid reaction models were applied to the experimental data to predict the behavior of the gasification reactions. The modified volumetric model predicted the conversion data well, thus the model was used to evaluate kinetic parameters in this study. The observed activation energy of biomass, sawdust and lignite gasification reactions were found to be in reasonable range and their rank was found to be sawdust > woodchip > lignite. The expression of apparent reaction rates for steam gasification of the three solids was proposed to provide basic information on the design of coal gasification processes.

본 연구에서는 죽산천 유역에 대해 지표수와 지하수의 통합거동을 유역 스케일로 장기간 모의할 수 있고 양수정의 공간분포 및 저수지 운영을 복합적으로 고려할 수 있는 유역단위 통합수문해석모형 SWAT-MODFLOW를 적용하여 지하수 양수 및 농업용 저수지가 하천유량에 미치는 영향을 평가하였다. 지하수 양수 및 농업용저수지 고려 유무에 따라 4가지 시나리오(1) 현 지하수 이용량 고려, 저수지 고려, (2) 현 지하수 이용량 고려, 저수지 미고려, (3) 지하수 이용량 미고려, 저수지 고려), (4) 지하수 이용량 미고려, 저수지 미고려(자연상태)를 구성하고 각 시나리오별로 하천유량의 변화를 모의한 결과, 죽산천 유역 출구부를 기준으로 지하수 양수로 인한 영향이 농업용 저수지에 의한 영향보다 상대적으로 크게 발생하였으며, 갈수량은 용수이용이 없는 자연 상태(natural flow)에 비해서 지하수 양수만의 영향으로 약 17%, 저수지만의 영향으로 약 11%, 양수 및 저수지의 복합영향으로 인해 약 23% 만큼 감소하는 것으로 분석되었다. 농업용 저수지로부터 떨어진 거리에 따른 하천유량의 변화를 평가하기 위해서 죽산천 본류를 따라 비갈수량을 산정한 결과, 저수지 관개용수의 회귀수 영향으로 하류로 내려갈수록 비갈수량이 증가하였으며, 죽산천 상류에 위치한 덕산 저수지로부터 약 6.5 km까지는 저수지의 영향이 상당히 미치는 것으로 분석되었다.

In this study, a watershed-based surface-water and groundwater integrated model, SWAT-MODFLOW was used to evaluate streamflow depletion induced by groundwater withdrawals and irrigation reservoirs for the Juksan-cheon watershed in South Korea. The streamflow responses to groundwater pumping and irrigation reservoirs were simulated under several different scenarios. The scenarios were (1) current pumping well withdrawals with reservoirs; (2) current pumping well withdrawals without reservoirs; (3) no pumping well withdrawals with reservoirs; (4) no pumping well withdrawals without reservoirs (natural condition). The simulated results indicated that the effects of groundwater pumping on streamflow depletion are a little more significant than those of irrigation reservoirs. Particularly, the groundwater withdrawals with irrigation reservoirs at current status (scenario 1) has induced the decrease of more than 20% in drought flow against the natural condition (scenario 4) at the outlet of the watershed. The specific drought flows through the main stream of Juksan-cheon watershed were simulated in order to assess the irrigation effects on downstream flows. It was found out that the specific drought flows are increasing as the distance from the reservoir increases due to the accumulation of the return flows to stream.

IT consulting is becoming a norm rather than exception in this age of smart work and information revolution. As IT consulting is one of the knowledge intensive services requiring high credence on both sides, maintaining a good trustful relationship is critical in sustenance of strategic partnership between business firms and IT service firms. Trust is known to be one of the salient constructs in service relationships. In this study, building from the social psychology literature, trust is conceptualized as two dimensions : cognitive and affective trust. Using two dimensions of trust as mediators, a research model is constructed for IT consulting specific context : relationship continuance intention as the dependent construct while expertise, service performance, reputation, relationship satisfaction and value similarity as antecedents of cognitive and affective trust. 145 data points were collected through a survey of IT service client project managers retrospectively asking their experience with IT consultants. Findings suggest that cognitive trust is associated with perceived level of expertise and service performance while affective trust with relationship satisfaction and value similarity, respectively. Interestingly, the paths from reputation are found to be statistically insignificant towards both dimensions of trust, indicating IT service context would be more practically outcome oriented than any other professional service context. Also, cognitive trust seems to maintain stronger influence on relationship continuance intention as anticipated. Implications and limitations are discussed at the end.

모바일 시스템에서는 비용 및 전력 효율이 중요하기 때문에 부동소수점 연산기 개발 시 32-비트 데이터 형식대신 24-비트 데이터 형식을 사용하는 것이 좋다. 하지만 24-비트 데이터 형식을 사용할 경우 32-비트 데이터 형식에 비해 연산기의 정확도가 낮아질 수 있다. 3D 그래픽과 같이 연속적인 부동소수점 연산 처리가 많이 요구될 경우 연산기의 정확도에 대한 논의와 검증이 중요하다. 나눗셈은 3D 그래픽에 사용되는 연산 중 OpenGL에서 규정한 정확도를 만족하기 가장 어려운 연산 중 하나이다. 현재까지 OpenGL에서 규정한 정확도를 만족하는 것이 대수적으로 검증된 24-비트 부동소수점 제산기는 알려진 바가 없다. 본 논문에서는 24-비트 부동소수점 제산기를 분석하고, OpenGL ES 3.0에서 규정한 $10^{-5}$의 정확도를 만족함을 대수적으로 검증한다.

Low-cost and low-power are important requirements in mobile systems. Thus, when a floating-point arithmetic unit is needed, 24-bit floating-point format can be more useful than 32-bit floating-point format. However, a 24-bit floating-point arithmetic unit can be risky because it usually has lower accuracy than a 32-bit floating-point arithmetic unit. Consecutive floating-point operations are performed in 3D graphic processors. In this case, the verification of the floating-point operation accuracy is important. Among 3D graphic arithmetic operations, the floating-point division is one of the most difficult operations to satisfy the accuracy of $10^{-5}$ which is the required accuracy in OpenGL ES 3.0. No 24-bit floating-point divider, whose accuracy is algebraically verified, has been reported. In this paper, a 24-bit floating-point divider is analyzed and it is algebraically verified that its accuracy satisfies the OpenGL requirement.

This case study presents a practical method to reduce resonant vibration of large vertical pumps. The pumps are driven at 400 rpm rated speed by induction motor. The vibration was not significantly large when operated at this rated speed. Large vibration was occurred when the pump was operated below the rated speed for flow control. Due to the large vibration resonance, variable speed operation of the pump was not possible for several months at worst cases. To find an efficient vibration control method, the flexural responses of pumps for both normal and transient operations were measured. The measured modal characteristics were compared with those of finite element analysis. When the pump was operated at a specific rpm, the natural mode whose resonance frequency is twice the rotating angular speed induced the large vibration. The retrofit utilizing stiffeners to reduce this resonant vibration were performed. Effects of designed stiffeners on reducing vibration were validated through tests after actual installation.

스마트폰의 급속한 보급과 함께 카카오톡, 페이스북, 문자메시지와 같은 문자기반 매체의 활용도가 증가하여 대인간의 주요 의사소통 매체로서 자리 잡고 있다. 본 연구에서는 문자기반 매체들에서 사회적 현존감이 서로 다르게 인지되고 있다는 점에 착안하여 각 매체별로 인지되는 사회적 현존감을 비교 분석하기 위해 설문을 구성하여 데이터를 수집하였다. 분석 결과 사용자는 자신이 가장 많이 사용하는 매체가 사회적 현존감이 높다고 인식하고 있었으며, 매체별로는 카카오톡, 페이스북, 문자메시지 순으로 사회적 현존감이 높게 인식되고 있었고, 각 매체별 사회적 현존감에는 차이가 있는 것으로 나타났다. 사용자가 사회성이 높고, 20대 이하이며, 학생일수록 다른 그룹들보다 사회적 현존감을 상대적으로 높게 인식하는 것으로 나타났다. 사회적 현존감이 실제 사용에 있어 영향을 미치고 있음을 찾아낸 본 연구에 후속으로는 어떠한 매체적 특성이 사회적 현존감의 차이를 불러일으키는지 연구가 필요할 것으로 보인다.

Since the advent of smart phone, a variety of text-based media are developed and used as popular communication tools even in mobile phone environment. This study explores differences in terms of users' perceived social presence level across different text-based media, specifically KakaoTalk, Facebook, SMS. A survey was conducted using items adopted from previous studies on social presence. 203 data points were collected and used for analysis. Across the whole sample, KakaoTalk is perceived as the highest in terms of perceived social presence level, followed by Facebook and SMS. Also, the users with higher level of sociality tends to reveal higher level of perceived social presence across all the media while younger and/or student users tend to maintain higher level of social presence perception across all the media. Further studies seem necessary investigating features of specific medium that may increase or decrease the perceived level of social presence.

본 연구의 목적은 in vitro 실험에서 human dermal fibroblast cell을 이용한 섬유아세포 증식과 콜라겐 생성을 통한 전층피부창상치유에 대한 효과를 알아보는 것이다. In vitro 실험에서, 베타글루칸 및 양성대조물질 oncostatin M을 사용하여 처치 후 24 또는 48시간 이후 MTT assay와 세포수 관찰을 통해 섬유모세포 증식효과에 대해 평가하였다. Procollagen 생산에 대한 효과를 평가하기 위해 베타글루칸 및 양성대조물질 oncostatin M 처치 48시간 후 hydroxyproline을 HPLC를 이용하여 정량하여 평가하였다. 창상재구축에 대한 효과를 평가하기 위해 베타글루칸 및 양성대조물질 fucoidan fraction 7을 FPCL 모델을 이용하여 평가하였다. 베타글루칸 처치군은 음성대조군 대비 0.1 mg/ml 이상의 농도에서 용량의존적이고 유의적인 OD 또는 섬유아세포수의 증가가 관찰되었다. 게다가 베타글루칸 처치군은 창상면으로 유주된 세포수가 음성대조군 대비 1 mg/ml 이상의 농도에서 용량의존적이고 유의적인 증가가 관찰되었다. 그러나 베타글루칸 처치군은 음성대조군 대비 모든 용량에서 procollagen 생산에 대한 유의적인 변화가 관찰되지 않았다.

The objective of the present study is to detect the effect of ${\beta}$-glucan originated from Aureobasidium on the proliferation and collagen production in human dermal fibroblast cells with wound repopulation in vitro. The proliferative effects were assessed using a MTT assay as well as cell counts at 24 and 48 hr after treatment. Hydroxyproline was measured as an index of procollagen production with reverse-phase high pressure liquid chromatography. Oncostatin M was used as a reference agent. In glucagon treated group, dose-dependent and significant increase of optical density or fibroblast cell numbers was demonstrated, when compared with those of control from 0.1 mg/ml concentration. In addition, the numbers of cells which had migrated into the wound defects were more significantly and dose-dependently increased than those of non-treated control. However, no meaningful effects on the procollagen production were observed.

Innovation becomes norm rather than exception in today's business, and accordingly firms are working on how to make their employees to work smarter using information systems and technologies. Smart work demands virtual collaboration and cooperation among team members in different places and different time. Sharing of knowledge among team members in these innovative activities are critical in every sense for the successful performance. This study explores the antecedents of knowledge sharing among team members in team-based innovation activities. Five factors (pleasure of knowledge sharing, self-efficacy, management support, rewards, and system usage) are identified through extant review of literature and an instrument is adopted and validated from previous studies. The instrument is adminitered against 138 individuals in and across 54 teams in a telecommunication firm. Except self efficacy, all the paths in the proposed research model is confirmed with different levels of relational coefficients towards the levels of knowledge sharing and innovation activities in teams. Surprisingly, findings indicate that intrinsic pleasure of sharing is most critical than management support, organizational rewards or system usage. This study fills the research gap in team management. Findings provide important implications for managing teams in coming virtual and smart environment.

본 연구는 양식장 퇴적토의 효과적 제거를 위해 초음파와 마이크로 공기를 이용한 퇴적토 부상제거를 위한 연구이다. 통영지역 양식장 퇴적토는 중금속 오염은 없으나 많은 양의 유기물을 함유한 것으로 파악되었고 수질보전을 위해 이들 퇴적토의 효과적 제거가 필요한 실정이다. 실험실 규모의 실험에서 초음파를 사용하지 않은 경우는 마이크로 공기를 주입하더라도 제거율은 초음파를 사용한 경우보다 현격히 낮아 초음파 사용이 필요함을 알 수 있었다. 또한, 마이크로 공기 주입시 응집제의 사용은 퇴적토 입자의 크기를 증가시켜 마이크로 공기에 의한 부상을 용이하게 하여 제거율이 크게 향상되었다. 퇴적토 양에 따른 부상제거 실험에서는 퇴적토 양이 증가함에 따라 제거율이 95.8% (1 g/L)에서 83.9% (8 g/L)로 감소하였으나, 대부분의 미세입자는 마이크로 공기에 의해 부상처리되어 제거되었음을 알 수 있었다.

The purpose of this study was to remove sediments obtained from breeding ground using supersonics and micro-air flotation method. Sediments from Tongyong breeding grounds showed no contaminations of heavy metals but had great amount of organics. Thus, efficient removal of sediments was required to preserve water quality near breeding ground. Supersonics treatment for sediments was determined to be essential because higher removal efficiency of sediments was obtained when supersonics treatment was used. In addition, application of coagulants increased removal efficiency because its usage increased particle size of sediments, which enabled easy trapping of sediments particle into micro-air bubbles. Removal efficiency of sediments slightly decreased from 95.8% (1 g/L) to 83.9% (8 g/L) at the tests for different amount of sediments, but most of tiny particles were removed from water where sand size particles were left in the bottom of reactors.

This study considers the effect of smartphone involvement for purchase intentions in fashion shopping malls based on mobile web apps and on PC web apps; in addition, it investigates the correlation between purchase intention in fashion shopping malls (based on activated PC web apps) and those of fashion shopping malls (based on newly created mobile web apps). The results of this study are: First, the analysis of smartphones factors showed that smartphones consist of 6 kinds of dimensions of 'appearance involvement', 'time and information search involvement', 'application involvement', 'entertainment involvement', 'communication involvement', and 'transaction involvement'. Second, the higher the entertainment and transaction involvement among descriptive variables for smartphone involvement were due to the positive responses displayed towards fashion shopping mall purchases based on mobile web apps. Third, a higher application and entertainment involvement in the descriptive variables for smartphones resulted in a positive response displayed for purchases in fashion shopping malls based on PC web apps shown in a regression analysis that verified the smartphone and purchase intention relationship in fashion shopping malls based on PC web apps. Fourth, consumers with high purchase intention in the existing PC web app based fashion shopping malls were shown to have a high purchase intention in mobile web app based fashion shopping malls due to the results of a correlation analysis that analyzed the relationship between purchase intention in PC web app based fashion shopping malls and mobile web app based fashion shopping malls.

본 연구에서는 청소년의 음식선택동기와 전통발효음식에 대한 태도 및 섭취행동과의 관련성을 분석하여 섭취행동에 영향을 미치는 요인들을 알아보았다. 서울시에 거주하는 고등학생 319명을 대상으로 음식선택동기, 전통발효음식에 대한 태도, 섭취행동에 관한 설문을 실시하여 분석하였으며 그 결과는 다음과 같다. 첫째, 음식선택동기는 건전성, 힐링, 편의성, 체중조절, 친숙성, 가격, 건강의 7개 요인으로 추출되었으며, 전통발효음식에 대한 태도와 섭취행동은 각각 하나의 요인으로 추출되었다. 둘째, 전통발효음식 만들기 체험을 하였던 집단의 건전성, 체중조절, 건강, 태도, 섭취행동 평균이 유의하게 높았다. 셋째, 음식선택동기는 전통발효음식에 대한 태도에 유의한 영향을 미쳤다. 전통발효음식에 대한 태도에 영향을 미치는 변수들의 상대적인 영향력은 가격(${\beta}$=.235)이 가장 컸으며, 그 다음은 힐링(${\beta}$=.190), 건강(${\beta}$=.175), 편의성(${\beta}$=.126)의 순이었다. 넷째, 전통발효음식에 대한 태도는 전통발효음식의 섭취행동에 유의한 영향을 미쳤다(${\beta}$=.549). 다섯째, 체중조절은 섭취행동에 직접적으로 영향을 미쳤다. 가격, 힐링, 건강, 편의성은 섭취행동에 직접적으로 영향을 미치지는 않았지만 태도를 통해 간접적으로 영향을 미쳤다. 결론적으로, 전통발효음식의 섭취행동을 높이기 위해서는 전통발효음식에 대한 긍정적인 태도의 형성이 중요하며 태도 형성에 영향을 미치는 음식선택동기에 대한 관심과 분석이 요구된다.

The aim of this study was to investigate the associations among the food choice motives, attitude to the traditional fermented food, and traditional fermented food consumption behavior in adolescents. Using a web-based self-completion questionnaire, food choice motives, attitude to the traditional fermented food, and frequency of traditional fermented food consumption were examined in 319 high school students in Seoul. As follows are the results of this study; first, food choice motives were emerged by seven factors, and labeled as good food, healing, convenience, weight control, familiarity, price, and health. Attitude to the traditional fermented food and consumption behavior of traditional fermented food were emerged as independent factor, respectively. Second, food choice motives had the significant effect on the attitude to the traditional fermented food(p<.05). Among them, price had the strongest effect(${\beta}$=.235), followed by healing(${\beta}$=.190), health(${\beta}$=.175), and convenience(${\beta}$=.126). Third, the consumption behavior of traditional fermented food was strongly influenced by the attitude to the traditional fermented food(${\beta}$=.549). Finally, weight control was the only direct driver for traditional fermented food consumption. Price, healing, health, and convenience acted as indirect drivers for traditional fermented food through the positive attitude to the traditional fermented food. In conclusion, since the formation of the positive attitude to the traditional fermented food is important for the increase of traditional fermented food consumption, the analysis of underlying food choice motives and attitude to the traditional fermented would be essential.

본 연구는 디지털 방송 환경 하에서 독립제작사 제작 방송 다큐멘터리의 소재 유형을 다양화하고 전문화 함으로써 시청자의 시청 권리를 확대하는데 연구목적을 두고 있다. 이를 위해 독립제작사 제작 방송 다큐멘터리인 <수요기획>(KBS 1TV)의 지난 10년 간 방송분을 분석대상으로 방송 소재를 유형화했다. 연구결과에 의하면, 완전 공모제 방식의 외주제작 방송 다큐멘터리인 <수요기획>의 제작에 국내 대부분의 독립제작사들이 참여했고, 제작규모 면에서 영세한 독립제작사들이 완전 공모제 방식을 적극 활용해 제작해 온 것으로 나타났다. 방송 소재 유형을 9가지로 분류해 분석한 결과, 시사 소재 유형이 33.4%, 휴먼 소재 유형이 18.5%를 차지하고 있었으며 독립제작사의 수익 극대화를 위해 연작 형식이 채택되기도 한 것으로 분석되었다. 방송 다큐멘터리의 소재 유형화 과정을 분석한 본 연구는 독립제작사의 방송 다큐멘터리 소재 선정의 유형을 체계적으로 분석했다는데 연구의의를 찾을 수 있다.

The purpose of this study is to expand the access rights of audience by diversifying and specializing types of material of TV documentary produced by independent production. To achieve this, we classified according to materials of <Wednesday Special>. This research suggested that almost the whole independent production produced this documentary in the way of complete posting system, especially small production. Also as the result, to analysis nine types of materials, types of current affairs and human sources have the most to produce occupied 51.9% and independent production have maximized profits through a series of works. The research value of this study is that this study analyzed the types of material selection of TV documentary produced by independent production systematically.

본 연구는 선형가속기의 회전불균형의 영향으로 발생 되는 CBCT 영상의 setup 오차 변화를 분석하여, 회전불균형에 대한 정도관리의 필요성을 연구 하였다. CBCT 시스템의 3차원 체적영상모드를 이용하여 $360^{\circ}$ 회전과 $180^{\circ}$ 회전으로 Catphan503 팬텀과 균질 팬텀의 3차원 영상을 획득하였고, setup 오차를 측정하기 위해 나선형 CT의 기준영상과 함께 비교 분석 하였다. 표준 정도관리의 절차를 시행하여 정상적인 상태를 확인하고, 임의적으로 갠트리의 회전균형을 조절한 후, 균형상태와 불균형상태의 각각 CBCT 영상에 대하여 X, Y, Z, Roll, Pitch, and Yaw의 6차원적 관점에서 setup 오차를 측정하고 분석하였다. Setup 오차의 변화율은 갠트리 회전균형의 조정 전 후를 확인한 결과, 직교 좌표계는 $360^{\circ}$의 회전에서 X축 방향으로 0.6 mm, Y축 방향으로 0.5 mm, Z축 방향으로 0.5 mm의 최대 변화율을 보였다. $180^{\circ}$의 회전은 X축 방향으로 0.9 mm, Y축 방향은 0.2 mm, Z축 방향은 0.3 mm의 최대 변화율을 보였다. 또한 회전 변환계는 회전 불균형이 커질수록 평균적인 값의 차이가 점점 증가하였고, 최대값은 $1.1^{\circ}$를 나타내었다. 영상의 분해능은 균형 조정 전 후 영상분석 툴에서 2 lp/cm 차이를 나타내었다. CBCT 시스템의 정도관리는 기준 권고안을 만족하였다. 갠트리의 회전 불균형이 클 때, setup 오차의 직교 좌표계의 변화는 크지 않았으나, 회전 변환계의 변화율은 기준 권고 값인 $1^{\circ}$에 해당하는 값과 초과하는 $1.1^{\circ}$를 나타내었다. 이는 갠트리의 불균형이 setup 오차에 영향을 미치는 것을 알 수 있었으며, 또한 회전 변환계의 setup 오차에 대한 6차원적인 보정이 더욱 요구됨을 알 수 있다. 그러므로 정확하고 정교한 영상유도 방사선치료를 수행하기 위해서는 갠트리의 균형도를 확인해야 하며, 정도관리 항목으로 추가되어야 한다고 사료되어진다.

This study investigated the rate of setup variance by the rotating unbalance of gantry in image-guided radiation therapy. The equipments used linear accelerator(Elekta Synergy TM, UK) and a three-dimensional volume imaging mode(3D Volume View) in cone beam computed tomography(CBCT) system. 2D images obtained by rotating $360^{\circ}$and $180^{\circ}$ were reconstructed to 3D image. Catpan503 phantom and homogeneous phantom were used to measure the setup errors. Ball-bearing phantom was used to check the rotation axis of the CBCT. The volume image from CBCT using Catphan503 phantom and homogeneous phantom were analyzed and compared to images from conventional CT in the six dimensional view(X, Y, Z, Roll, Pitch, and Yaw). The variance ratio of setup error were difference in X 0.6 mm, Y 0.5 mm Z 0.5 mm when the gantry rotated $360^{\circ}$ in orthogonal coordinate. whereas rotated $180^{\circ}$, the error measured 0.9 mm, 0.2 mm, 0.3 mm in X, Y, Z respectively. In the rotating coordinates, the more increased the rotating unbalance, the more raised average ratio of setup errors. The resolution of CBCT images showed 2 level of difference in the table recommended. CBCT had a good agreement compared to each recommended values which is the mechanical safety, geometry accuracy and image quality. The rotating unbalance of gentry vary hardly in orthogonal coordinate. However, in rotating coordinate of gantry exceeded the ${\pm}1^{\circ}$ of recommended value. Therefore, when we do sophisticated radiation therapy six dimensional correction is needed.

안전채수량 개념은 지하수 양수와 함양과의 균형에 초점을 맞춘 방법으로 자연적으로 배출되는 지하수 유출량에 대해서는 고려하지 못한다. 또한 하천과 연결된 충적대수층은 물공급과 수질면에서 상호 연결되어 있기에 별도로 이해하거나 관리할 수 없다. 따라서 미국 캔자스의 일부 지역에서는 기존의 안전채수량을 재평가하여 자연 지하수 배출량과 하천-대수층 상호작용을 고려한 수정된 안전채수량 개념을 제시하였고, 기저유량의 일정부분을 포함시키기 위해 최소하천유출량(MDS) 개념을 도입하였다. 본 연구에서는 수정된 안전채수량 개념을 우리나라에 맞게 적용하기 위해 하천유출과 연계한 개발가능량 산정방법을 제시하였다. 이를 위해 유출수문곡선으로부터 기저유출량을 분리하여 유황곡선으로 표시한 후, 결정된 최소하천유출량에 해당하는 양을 누적기저유출량에서 배제함으로써 개발가능량을 결정한다. 이 방법을 SWAT-K모형을 이용하여 통합모델링이 수행된 바 있는 무심천 유역에 대해 적용한 바, 연평균 개발가능량은 약 86 mm로 산정되었고, 각 소유역별로도 하천과 연계한 지하수 개발가능량을 구할 수 있었다.

The concept of safe yield places an emphasis on balancing groundwater withdrawal with groundwater recharge but ignores naturally occurring groundwater discharge. Because streams and their alluvial aquifers are closely linked in terms of water supply and water quality, to be properly understood and managed they must be considered together. Therefore, some districts in Kansas have reevaluated their safe-yield policies to account for natural groundwater discharge and stream-aquifer interactions by amending their safe-yield regulations to include a portion of baseflow as the minimum desirable streamflow (MDS). This study proposes a modified safe-yield policy in which the drought flow is chosen as the MDS. Baseflow separation was conducted from streamflow hydrograph and the results are presented as a flow-duration curve. The exploitable groundwater can be determined by subtracting MDS from the cumulative baseflow. This method was tested in the Musimcheon watershed, which was validated for streamflow using the SWAT-K model. The annually averaged exploitable groundwater in the whole watershed was estimated to be 86 mm. The exploitable groundwater amounts were also estimated for each subwatershed in the Musimcheon watershed.

본 연구에서는 복하천 중상류 유역에 대해 준분포형 유역수문모형 SWAT-K를 적용하여 자연유량을 산정하고, 하천유량 변화를 야기하는 지하수 양수량, 하천수 취수량, 하수처리수 방류량 등의 인위적인 요인으로 인한 영향을 평가하였다. 2006년부터 2013년까지의 자연상태의 하천유량을 모의한 결과 최저유량은 $1.7m^3/s$, 평균유량은 $26.2m^3/s$, 갈수량은 약 $2.0m^3/s$로 산정되었다. 지하수 이용, 하천수 취수, 하수처리수 방류 등 각각의 인위적 요인에 의한 하천유황의 상대적 변화를 분석한 결과, 갈수량은 지하수 양수로 인해 자연상태에 비해 약 34% 감소, 하수처리수 방류와 하천수 취수의 복합 영향으로 인해 약 15% 증가, 지하수 양수, 하수처리수 방류와 하천수 취수의 복합 영향으로 약 19% 만큼 감소하는 것으로 분석되었다. 복하천 본류를 따라 모의된 자연유량 자료를 이용하여 비유량의 거동 특성을 분석한 결과, 중상류 유역에서는 지배면적이 증가할수록 비풍수량, 비평수량, 비저수량, 비갈수량 등의 값이 증가하는 경향을 나타내었으며, 하류부로 내려오면서 지배면적이 약 180 $km^2$ 이상에서부터는 면적과 상관없이 거의 일정한 비유량 값을 나타내는 것으로 분석되었다.

The objectives of this study are to construct the natural streamflow in the Bokhacheon middle-upper watershed using the SWAT-K model and to assess the impacts of groundwater withdrawals, water intake, treated sewage water release on streamflow. The simulated natural streamflow from 2006 to 2013 showed the minimum discharge of $1.7m^3/s$, the annual average discharge of $26.2m^3/s$, the drought flow of $2.0m^3/s$ at the outlet of the study area. The simulated results indicated that the groundwater pumping has induced the decrease of 34% in drought flow against the natural condition and the net water release has caused the increase of 15%, while the combined effects of the groundwater pumping and the net water release have induced the decrease of 19%. It was found out from the simulated natural streamflow data that the specific discharges of the abundant flow, normal flow, low flow, drought flow in the upper-middle channels of the Bokha-cheon watershed have a tendency to increase as the drainage area increases, but the specific discharges showed almost constant values at any downstream point with drainage area more than about 180 $km^2$.

The purpose of this study is to analyze the early experience of the laparoscopic adhesiolysis for the intestinal obstruction due to postoperative adhesion. Seven patients were included in this study. The median age of those patients was 13, and there were 3 males and 4 females. Previous diagnosis and surgical procedure were various in seven cases, including small bowel resection with tapering enteroplasty, Boix-Ochoa fundoplication, Ladd's procedure with appendectomy, mesenteric tumor resection with small bowel anastomosis, ileocecal resection and anastomosis, primary gastric repair, and both high ligation. A successful laparoscopic adhesiolysis was performed in one who had high ligation for inguinal hernia and had a single band adhesion. Six out of 7 (86%) cases needed to convert open surgery due to multiple and dense type of adhesion. In conclusion, laparoscopic approach with postoperative small bowel adhesion seems safe. However, it might be prudently considered because of high rates of conversion in children.