Sandwich structures are general-purpose structures that can reduce the structural weight of composite ships. Core materials are essential for these structures, with polyvinyl chloride (PVC) foams being the most popular. These foam core materials are subjected to various tests in the development process, and must satisfy the performance requirements of several ISO and ASTM standards. Therefore, a procedure for evaluating the performance of foam core materials was proposed in this paper. In addition, prototypes were fabricated using a commercial PVC foam core product in accordance with the structural design of an 11 m fiber-reinforced plastic yacht. Then, a case study was conducted on the proposed evaluation procedure. The proposed procedure facilitates the understanding of the performance requirements and evaluation of core materials used in composite ships and is expected to be utilized in developing core materials for marine structures.

Sea trial tests are necessary to verify speed-power performance, and are an import contract between ship owners and shipyards. The International Organization for Standardization (ISO) published ISO 15016:2015, which specifies the correlation method between model and full-scale ships. The results of sea trials have been questioned because of the uncertainty of speed and power measurements, especially when sea conditions differ from ideal calm water conditions. In this paper, such uncertainties were investigated by utilizing the standard speed-power trial analysis procedure defined in ISO 15016:2015 through Monte Carlo simulations. It was found that the expanded uncertainty of the delivered power (PDid) at 95 % confidence interval (k = 2) was ±1.5 % under 75 % MCR conditions.

Osteoarthritis occurs when the cartilage that gradually deteriorates as common aging-associated disease in humans and animals. There is no cure, but the treatments are available to manage to relieve pain through medication such as steroids. Growing interest has been focused on the role of cell-based therapies using mesenchymal stem cells (MSCs). In addition, mesenchymal stem cells can be isolated from almost adult tissues and known for their potential of becoming cartilage. Clinical and experimental studies indicate that the development of treatment using stem cells is double-edged sword involving a possibility such as tumorigenesis. This study focused on the electrical features during articular cartilage development and hypothesized that external electric fields promote pre-chondrogenic condensation without concern relating to genetic modification or exogenous factors. Here, it has been reported that exogenous direct electric fields drive pre-chondrogenic condensation which is the stage where cartilage formation begins by condensation of stem cells and cartilage cells in the microenvironment of the joint. Time-dependent observations also support the contribution of electrical stimulation (ES) to induce gradual aggregation of MSCs into highly compact structures within 3 days. Collectively, our findings provide the potential of electrical stimulation-driven chondrogenesis of mesenchymal stem cells in the absence of exogenous factors for repair of cartilage defects.

본 연구는 실제 대인관계에서 형성된 관계의 친밀감이 게임 플레이 시 플레이어의 게임 및 사용자 경험에 영향을 줄 것이라 보았다. 그러나 사회적 관계 정도에 따른 게임 사용자 경험에 차이가 있음에도 불구하고 지금까지의 선행 연구에서는 게임 플레이어의 사회적 네트워크나 팀워크에 대해 분석한 연구는 매우 드물다. 따라서 본 연구는 모바일 전략 게임 내에서 플레이어 간의 사회적 관계 정도가 게임에 대한 협동심, 만족, 이용의도에 미치는 효과를 검증하기 위해 모바일 게임 앱 플레이테스트 실험처치 방법론을 통해 분석하였다. 또한 사회적 관계에 따른 효과의 차이를 순수하게 알아보기 위해 참여자의 게임 몰입(Flow)을 공변량(Covariance)으로 하여 공분산분석(ANCOVA)을 실시하였다. 본 연구는 실시간 전략 게임인 ‘클랜시 오브 로얄' 게임 앱을 이용하여 진행되었다. 연구결과, 사회적 관계가 높을수록 게임에 대한 협동심과 만족은 높아지는 것으로 나타났다. 이러한 본연구의 결과는 모바일 게임 기획 시 플레이어의 인적 네트워크와 게임 진행 방식에 대한 이론적, 실무적 함의를 갖는다.

Insect cuticle tanning (pigmentation and sclerotization) is a complex and vital process, which includes hydroxylation of initial amino acid, tyrosine, to DOPA and decarboxylation of DOPA to dopamine. In the pigmentation process, dopamine further undergoes two N-acylation reactions to yield N-acetyldopamine (NADA) and N-β-alanyldopamine (NBAD). In the former reaction, arylalkylamine N-acetyltransferase (AANAT1) converts dopamine to NADA, and in the later reaction, aspartate 1-decarboxylase (ADC) provides β-alanine, which is conjugated with dopamine catalyzed by NBAD synthase (Ebony) for production of NBAD. In this study, we performed functional genomics of TmAANAT1, TmADC and Tmebony to determine whether they are required for cuticle pigmentation in Tenebrio molitor adults. Loss of function of these genes by RNAi caused the significantly darker body color than that of control animals. Note that, although all phenotypes exhibited dark cuticle pigmentation, RNAi of either TmADC or Tmebony only altered brownish outer region of the cuticle to dark/black. In contrast, RNAi of TmAANAT1 had no effect on the brown hue of the outer cuticle layer, but less or no pigmented inner region of the cuticle became significantly darker than those of control adults. These results suggest that, like that seen in TcAANAT1- or TcADC-deficient Tribolium castaneum adults, NADA produced by a reaction by TmAANAT1 contributes the lighter inner cuticle layer(s), whereas NBAD appears to do the highly pigmented outer cuticle layer(s) of the cuticle of T. molitor adults. This work was supported by NRFs (NRF-2015R1A6A3A04060323 and NRF-2018R1A2B6005106).

The global apparel manufacturers have produced apparel and textiles to meet consumers’ needs. Recently, they have applied the sophisticated technologies and more effective organizational systems to improve the efficiencies in apparel product development and their applications have led to enhancement of consumers’ satisfaction (Kunz, Karpova, & Garner, 2016). In this study, we identified novel approaches of product innovation strategies including technological innovation and organizational effort which a representative mass-scale Bangladeshi apparel manufacturer, Ananta Group has practiced. For data collection, in-depth interviews were conducted with four managerial staffs who were managers and assistant managers working at the research and development (R&D), production, marketing and quality control departments in Ananta Group. The interviewees were male employees having degrees higher than bachelor’s degree in textile engineering. Their work experience years ranged from 5 to 15 years within their respective fields and their ages ranged from 28 to 55 years (m=40). Qualitative approach was used to analyze the data. It was found that Ananta Group has used innovative technologies such as advanced softwares, process systems and machineries in new product development and its organizational effort of running specialized teams of design, new product development, and marketing activities has enhanced technological innovation. These findings provide global apparel manufacturers with valuable information on how product innovation strategies for new apparel development are important and what technological approaches can be used to accomplish it.

Nodal transport methods are proposed for solving the simplified even-parity neutron transport (SEP) equation. These new methods are attributed to the success of existing nodal diffusion methods such as the Polynomial Expansion Nodal and the Analytic Function Expansion Nodal Methods, which are known to be very effective for solving the neutron diffusion equation. Numerical results show that the simplified even-parity transport equation is a valid approximation to the transport equation and that the two nodal methods developed in this study also work for the SEP transport equation, without conflict. Since accuracy of methods is easily increased by adding node unknowns, the proposed methods will be effective for coarse mesh calculation and this will also lead to computation efficiency.

To correctly predict the neutron behavior based on diffusion calculations, it is necessary to adopt well-specified boundary conditions using suitable diffusion approximations to transport boundary conditions. Boundary conditions such as the zero net-current, the Marshak, the Mark, the zero scalar flux, and the Albedo condition have been used extensively in diffusion theory to approximate the reflective and vacuum conditions in transport theory. In this paper, we derive and analyze these conditions to prove their mathematical validity and to understand their physical implications, as well as their relationships with one another. To show the validity of these diffusion boundary conditions, we solve a sample problem. The results show that solutions of the diffusion equation with these well-formulated boundary conditions are very close to the solution of the transport equation with transport boundary conditions.

미디어의 구성 요소 중 하나인 사운드는 인간의 청각은 물론 인지와 지각을 자극하여 사용자가 상황이나 공간에 대해 보다 쉽게 이해할 수 있도록 하고 미디어가 전하고자 하는 정보를 효과적으로 전달하는 역할을 한다. 그러한 측면에서, 게임에서의 효과음은 콘텐츠를 전달하는데 중요한 역할을 한다. 게임이 플레이되는 동안 연출되는 다양한 효과음은 사용자에게 밝은 분위기를 조성하고 게임 진행의 긴장감을 놓치지 않게 하며 사용자가 자연스럽게 게임에 집중하게 만든다. 특히 게임에서의 자연스러운 효과음은 게임의 배경음악과 더불어 사용자의 몰입과 사실성을 증대시킨다. 본 연구는 게임 효과음의 사실성 정도에 따른 공간적 실재감, 몰입, 정서적 자기조절, 공격적 태도 및 공격 행동을 측정하기 위해 플레이테스트 실험 방법론을 수행하였다. 실험에 사용된 FPS 게임은 'Left 4 Dead 2'이며, 무기 효과음을 다르게 처치하여 남녀 각각 40명씩 총 80명을 대상으 로 실험을 수행하였다. 연구결과, 공간적실재감, 몰입, 그리고 정서적 자기조절은 실재음을 사용한 게임에서 더 높은 수준을 보였다. 또한 공격적 태도 역시 사실적인 무기 효과음을 사용한 게임에서 더 높은 수준을 나타냈다. 본 연구는 게임 효과음의 사실성이 사용자의 게임 경험과 감정, 그리고 공격성에 영향을 미칠 수 있다는 점에서 향후 게임 효과음 디자인에 대한 이론적 함의를 제공한다.

The purpose of the study was to find grey matter (GM) and white matter (WM) volume reduction in the brain reward system among patients with alcohol dependency. This study investigated regional GM and WM in chronic alcoholic patients, focusing primarily on the reward system, including principal components of the mesocorticolimbic reward circuit as well as cortical areas with modulating and oversight functions. Sixteen abstinent long-term chronic alcoholic men and demographically matched 16 healthy control men participated in the study. Morphometric analysis was performed on magnetic resonance brain scans using voxel-based morphometry (VBM)-diffeomorphic Anatomical Registration through Exponentiated Liealgebra (DARTEL). We derived GM and WM volumes from total brain and cortical and subcortical reward-related structures. Morphometric analyses that revealed the total volume of GM and WM was reduced and cerebrospinal fluid (CSF) was increased in the alcohol group compared to control group. The pronounced volume reduction in the reward system was observed in the GM and WM of the nucleus accumbens (NAc), GM of the amygdala, GM and WM of the hippocampus, WM of the thalamus, GM and WM of the insula, GM of the dorsolateral prefrontal cortex (DLPFC), GM of the orbitofrontal cortex (OFC), GM of the cingulate cortex (CC), GM and WM of the parahippocampal gyrus in the alcohol group. We identified volume reductions in WM as well as GM of reward system in the patients with alcohol dependency. These structural deficits in the reward system elucidate underlying impairment in the emotional and cognitive processing in alcoholism.

Previous research developed lists of the most frequently used phrasal verbs in native English corpora. This study aims to discover how these high frequency phrasal verbs were presented in high school English textbooks in Korea. A high school English textbook corpus comprising 189,203 words taken from the listening scripts and reading passages of eight different textbook series was developed for the study. A corpus-based analysis of phrasal verbs revealed that each textbook series covered only 30% of most commonly used phrasal verbs in native corpora. In addition, the phrasal verbs used in the different textbook series rarely overlapped, suggesting a lack of systematic selection process. Among the recursive phrasal verbs appearing in the textbook series, high frequency phrasal verbs were more likely to be recursive and evenly distributed. A comparative analysis conducted with a referential corpus revealed that the textbooks employed fewer phrasal verbs than their comparative counterparts. In terms of meaning, 91% of high frequency phrasal verbs in the textbooks delivered their most frequent meanings while the rest 9% did not. The results of this study support the necessity of pedagogical guidelines for phrasal verbs.

The concept of retail therapy which refers to “the phenomenon in which consumers buy things to make themselves feel better” (Kacen, 1998) has been used by the U.S. retail firms in marketing (Kang & Johnson, 2010). Previous studies found that retail therapy concept was associated to consumption behaviors including compulsive buying (Faber & O’Guinn, 1992; O’Guinn & Faber, 1989). Frost et al. (1998) found that compulsive hoarders show compulsive buying tendencies. O’Guinn and Faber (1989) found that compulsive buyers are more likely to confirm compulsivity as a personality trait with a low self-esteem. Lack of research into association of retail therapy to compulsive consumer behaviors motivated us to pursue this study which investigate relationships among retail therapy, compulsive buying and compulsive hoarding, and to examine the moderating effect of consumers’ personality traits on the relationship between retail therapy and compulsive hoarding. Our research questions are: (1) How retail therapy is related to compulsive buying and compulsive hoarding? and (2) Which personality traits moderate the relationship between retail therapy and compulsive hoarding? Based on the literature review, the following hypotheses were proposed. H1: Retail therapy is positively related to compulsive buying; H2: Compulsive buying is positively related to compulsive hoarding; H3: Retail therapy is positively related to compulsive hoarding & H4: Personality trait moderates the relationship between retail therapy and compulsive hoarding. The researchers used 12 items to measure retail therapy (Kang, 2009), 6 items to measure compulsive buying (Faber & O’Guinn, 1992), 9 items to measure compulsive hoarding (Frost, Sketekee, & Grisham, 2004) 8 items of Big Five Inventory (Rammstedt & John, 2007) and 15 item Narcissistic Personality Inventory (NPI) (Ames, Rose & Anderson, 2006) to measure personality trait based on 7‑point Likert scales (1 = strongly disagree, 7 = strongly agree). The online survey was conducted with college students enrolled at a major Midwestern University. A total of 354 undergraduate and graduate students’ responses were used to analyze data. A principal component factor analysis with varimax rotation was conducted to evaluate the measurement of each construct. The factor loadings were above of 0.60, indicating acceptable convergent validity. Reliabilities with Cronbach’s alphas for retail therapy,compulsive buying, compulsive hoarding and personality trait construct were 0.96, 0.81, 0.90 and 0.81 respectively, exceeding the suggested level of 0.70. Simple linear regression was performed to test hypotheses. The results revealed that F statistic (F(1, 352)=126.53, p =.000) was significant and regression coefficient was statistically significant. Therefore, H1 was supported and consistent with previous findings (Faber & O’Guinn, 1992). The regression coefficient for the path from compulsive buying to compulsive hoarding was statistically significant (F(1, 352)=77.15, p=.000). Therefore, H2 was supported and consistent with Frost et al. (1998)’s study. The retail therapy contributed significantly to the prediction of compulsive hoarding with the statistically significant regression results (F(1, 352)=20.28, p=.000), supporting H3. From the principle component analysis with varimax rotation, four factors were extracted from 23 personality trait measurement items which are labeled as “authority-leadership narcissism”, “self-esteem narcissism”, “positive disposition”, and “negative disposition”. All factor loadings were above 0.60 for their respective factors. Then, the researchers divided one single group into four personality trait groups, using these four factors. 4%, 27.1%, 53.7% & 15.3% participants represented “authority-leadership narcissism”, “self-esteem narcissism”, “positive disposition” & “negative disposition” group respectively. Simple regression analysis was performed to test H4. The regression coefficients for positive disposition group (F(1, 188)=13.19, p=.000) and negative disposition group (F(1, 52)=5.01, p≤.05) were statistically significant. H4 was partially supported. The results indicated that people from two groups characterized by positive/negative personality tend to engage in compulsive hoarding to alleviate their negative feelings or mood. Anyone with narcissistic personality with a high self-efficacy may not be engaged in compulsive hoarding even when a therapeutic treatment is made through shopping. They tend to purchase products for changing their moods, but their therapeutic behavior doesn’t lead to compulsive hoarding, which causes sufferings in the end. The low self-esteem has been presented with people being engaged in compulsive behaviors (Marlatt et al., 1988). These findings can help apparel marketers develop the strategies to upgrade their sellingenvironment entertaining so that their customers’ moods are repaired and customers feel satisfied through therapeutic shopping behavior. This study has a limitation that prevents us from generalizing the results to the young consumer population due to sample size to college students.

해수 중 광학적 특성 때문에 유색 용존유기물은 위성자료에 기반한 해양의 엽록소와 일차생산력의 정확한 측정에 영향을 미칠 수 있다. 따라서 본 연구에서는 2009과 2011년 여름철을 대상으로 서로 특이하게 다른 결과를 보고하고자 하였다. 이 두 시기의 여름철 차이는 것은 용존유기물에 영향을 주는 주요 공급원이 다른 것으로 나타났다. 그리고 현장 측정치와 위성자료로 부터 얻어진 엽록소 농도를 비교하여 위성자료로부터 구한 엽록소 농도 측정에 대한 용존유기물의 영향을 보았다. 그 결과, 2009년 MODIS를 이용한 엽록소 농도와 현장 측정된 엽록소 a 농도는 서로 유사하였으나, 2011년과 같이 유색용존유기물의 농도가 높았던 시기에는 이 두 농도간에 유의한 차이가 나타났다. 2011년 여름 MODIS 자료와 비교하였을 때, GOCI 자료는 엽록소와 유색용존유기물 모두 현장 측정치 자료와 잘 일치하였다. 수직 혼합에 의해 공급된 표층 해수 중 높은 유색용존유기물의 존재는 위성자료에 의한 엽록소 농도의 과대평가에 영향을 주는 것으로 보인다.

30 LMH의 정유량 플럭스로 운전하는 MBR에서, 휴지 및 역세정에 따른 한외여과 분리막의 오염을 조사하였다. 또한, 연속적인 공기세정과 비교하여 분리막 여과저항을 최소화하기 위한 간헐적인 공기세정을 평가하였다. 여과 조건은 14.5분 여과와 0.5분의 휴지를 유지하였으며, 역세정 시간은 휴지 시간과 동일하게 운전하였다. 공기세정이 정지하는 동안에 분리막 표면의 겔층 위에 케잌이 빠르게 축척되었으며, 역세정으로 겔층과 케잌층의 복합층은 쉽게 제거되었다. 역세정 후에 공기세정이 정지하는 동안 분리막 표면에 케잌이 형성되어 공경 내부의 오염현상을 억제하였다. Pearson 상관성을 조사한 결과, 간헐적인 공기세정에서 공기 세정이 정지하는 시간과 분리막의 오염은 매우 연관성이 높다는 것을 알았다. 즉, 간헐적인 세정에서 공기세정이 정지하는 시간이 갈수록 오염억제에 효과적이었다.

침지식 분리막 모듈에서 공기강도에 따른 분리막 위치에 대한 오염을 조사하였다. 분리막의 충진밀도가 낮은 곳에서 높은 유체 유속을 나타내었으며, 유체 속도는 기-액 주입률에 비례하였다. 전단응력은 기-액 주입률 및 유체 유속에 비례하였다. 비가역오염(Rir)은 흡입 압력이 가까운 부분에서 가장 높게 나타났다(position 1). 비가역오염에 대한 저항과 분리막 고유 저항의 비(Rir/Rm) 및 비가역오염에 대한 저항과 가역오염의 저항의 비(Rir/Rr)도 position 1에서 가장 높게 조사되었다. 비가역오염(Rir)은 흡입 압력이 높은 곳인 position 1에 오염물질이 축적되어진 결과이다. 분리막 위치에 따른 오염현상은 모듈 디자인 최적화에 중요한 인자임을 알았다.

침지식분리막 오염을 최소화하기 위한 두 가지 공기세정방식을 비교하였다. 연속적인 공기세정과 단계별 공기량을 증가시키는 방식을 연구하였다. 15분의 여과 중에 세정공기의 증가는 5분마다 단계별로 공기량을 증가시켜주었다. 모의 여과 원수에 분말활성탄을 10 g/L 이하 그리고 카올린은 20 g/L 이하로 준비하였으며, 플러스는 80 LMH로 하였다. 단계별 공기세정방식은 연속적인 공기세정 방식보다 분리막 오염억제에 효과적이었다. 추가적으로 주입된 응집제는 분리막 오염저감을 보다 향상시켰다. 연속적인 공기세정의 오염현상은 공경막힘과 분리막 표면에 지속적인 입자의 축적에 기인하였다.