본 논문에서 사고로 누출된 삼중수소에 의한 농작물 오염평가 모델을 제시한다. 본 논문에서 제시된 모델은 동적격실모델로써 작물의 성장 방정식을 도입한 것이 특징이며, 이로부터 삼중수소 피폭시 작물의 성장단계에 따른 오염 정도를 예측할 수 있다. 시스템은 크게 대기, 토양, 작물격실로 구성되며, 격실의 삼중수소 농도 변화는 비선형 상미분방정식으로 표현되므로 시간에 따른 각 격실의 삼중수소 농도가 계산된다. 모델의 검증을 위해 배추 및 무에 대한 삼중수소 피폭 실험을 수행하였다. 생육단계별 오염 효과를 조사하기 위해 각기 다른 생육단계에 있는 배추와 무를 독립적으로 HTO 증기에 노출시켰으며, 피폭 후 오염된 작물의 tissue free water tritium(TFWT) 및 organically bound tritium(OBT) 농도를 측정하였다. 측정된 작물 부위별 삼중수소 농도 데이터와 모델 예측 값은 대체로 잘 일치하였다.

반복 비선형 계획법의 하나인 선형화 기법을 절대수령의 전제아래 합성 구조물의 최적 설계에 옹용한 다 선형화 기법은 설계문제의 제약조건을 선형화된 둥가 제약조건으로 변형시키며 actlve-set 정책올 구 사한다. 결과， 매 설계단계에서 풀어야 할 상태 및 수반 방정식의 수를 줄임으로써 실질적인 계산의 절감 올 기한다. 기둥으로 받쳐진 판-보 구조물은 최적화 기법의 능력을 시험키 위한 합성구조물의 좋은 예로 서， 설계결과 선형화 기법은 만족할만한 수렴치로써 최적해를 산출함을 알 수 있고 나아가 이 방법은 모 든 종류의 최적화 문제에 적용될 수 있을 것으로 보인다.

An economic downturn can occurred through unexpected events in various fields, such as the subprime mortgage crisis and the outbreak of Coronavirus Disease-2019 (COVID-19). Trade credit is important for small- and medium-sized enterprises (SMEs), especially during a monetary contraction, as it is the last option for firms that lack bank credit. This study aims to determine whether trade credit is profitable for the buyer and supplier firms during and after a financial crisis. We use panel data consisting of all trade credit transactions and financial statements of 5,751 Korean firms during the period 2008–2012. It shows that trade credit is more profitable for both buyers and suppliers in the post-crisis period than during the crisis. Moreover, trade payable is more effective for unconstrained buyers than for constrained buyers. Finally, a mixed strategy is superior to an aggressive or passive strategy of SMEs. The results suggest less profitability of trade credit during a period of contraction and greater sensitivity of the buyer SMEs, emphasizing the idiosyncratic liquidity strategy of each firm. This study can be helpful to develop a strategy of profitable trade credit for SMEs and to establish a policy of managing liquidity for the authority.

This study investigated a suitable method that could be applied for Asian chain fern [Woodwardia japonica (L. f.) Sm.] to propagate gametophytes and promote sporophyte formation. The gametophytes used in all experiments were obtained from germinated spores in vitro and were subcultured at 8-week intervals. The most appropriate media for gametophyte propagation was identified by culturing 300 ㎎ of gametophyte in Murashige and Skoog (MS) basal medium (1/8, 1/4, 1/2, 1, 2), and Knop medium for 8 weeks. As a result, fresh weight of the gametophyte was increased by 56.7-fold on MS medium. Moreover, antheridium formation as well as gametophyte growth was improved on MS medium, especially. To improve the sporophyte formation ex vitro, 1.0 g of gametophyte was ground with distilled water and spread on eight combinations onto four different culture mediums, such as bed soil, peat moss, perlite and decomposed granite. Then generation and growth of sporophytes were investigated after cultivation for 10 weeks. As a result of this experiment, peat moss had a promotive effect of sporophyte formation at single-use and mixed culture soils. In particular, a mixture of bed soil, peat moss and perlite in a 1:1:1 ratio (v/v/v) led to the accelerated formation (782.5 ea/pot) and the frond growth of sporophytes. This included increases in length and width of fronds. However, promotive effect of gametophyte growth and sporophyte formation was not found at single-use and treatment with high ratio of bed soil.

This study is conducted to investigate the effects of growth characteristics (GC) and DPPH radical scavenging activity (DRSA) of the heading lettuce ‘Fidel’ depending on four concentrations of activated mineral groups (AMG: 1.6% active minerals and 0.03% CaO) added to basic nutrient solutions (diluted by 0, 0.05, 0.1, and 0.2%) and on four different light-emitting diodes (LED; B:R:W ratio = 0:1:12, 0:1:9, 0:5:5, and 2:3:5). Both 0.1 and 0.2% AMG showed better GC of lettuce in plant width, plant length, leaf width, leaf length, and the number of leaves than those of other AMG, while leaf thickness and chlorophyll value did not show significant difference among all AMG. Moreover, 0.1 and 0.2% AMG showed heavier shoot fresh weights than those of other AMG. As for the combinations of AMG and LED, B0:R5:W5 showed the best lettuce GC regardless of AMG compared to other AMG and LED combinations. As shown in the above results of LED, although there was a difference in lettuce growth by LED, the differences of lettuce growth by AMG were statistically significant. The DRSA was the highest at 82.8% in B2:R3:W5, followed by B0:R5:W5 at 77.8%. LED showed differences but AMG did not affect DRSA. Therefore, the optimal conditions in plant factory for GC and DRSA of the lettuce were 0.1% AMG and B0:R5:W5.

Fruit trees are a key part of agriculture in rural areas and have recently been a part of ecotourism or agrotourism. This study analyzes user segmentation based on user motivation to determine characteristics of potential customers in fruit tree farms, and thereby develop fruit tree experience and educational programs. We conducted a survey of 253 potential customers of fruit tree experience programs in September 2017. Data were evaluated using factor and cluster analyses. The results of the cluster analysis identified four distinct segments based on potential customers' motivations, that is, activity-oriented, learning-oriented, leisure-oriented, and purchase-oriented. These clusters showed that significant differences in the preference of potential customers exist. Different markets were segmented based on the benefits sought by users. The segments’ characteristics were identified and activities relevant to each segment were proposed for rural tourism. Lastly, this study suggests directions for development of fruit tree farm experience and educational programs.

This study was conducted to apply a horticultural therapy program to childhood cancer patients, to analyze their psychosocial changes and thus to examine its possibility as a way to manage the recovery of childhood cancer patients. This study was conducted on patients who were diagnosed with childhood cancer, and they were divided into the experimental group (8 patients who visited H association offices located in 3 cities and participated in the horticultural program) and the control group (5 patients who did not participate in the program). The homogeneity between the two groups before conducting the program was compared, and there was no statistically significant difference, which proved that the two groups were homogeneous. After conducting the program, the score of social immaturity, one of the sub-categories of problem behaviors, of the experimental group was statistically significantly lower than that of the control group (p=.019). Changes before and after the program within the groups were compared, and the somatization score (p=.039) of the experimental group (p=.039) after the program was 1.13, down from 2.13 before the program. The social immaturity score (p=.017) of the experimental group after the program was 1.00, down from 2.63 before the program, and the attention problem score (p=.026) of the group after the program was 1.25, down from 2.50 before the program. The total problem behavior score (p=.034) of the experimental group after the program was 9.63, down from 18.50 before the program, showing a statistically significant decrease. The cumulative subjective mood score (p=.000) of the experimental group throughout the entire sessions after the program was 7.82, up from 6.99 before the program, showing a statistically significant increase. Therefore, it can be concluded that the horticultural therapy program developed based on the ‘relaxationsocial support-cognitive behavior’ strategy was effective to reduce the negative psychosocial state of childhood cancer patients.

Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.

Background : Cudrania tricuspidata Bureau is a widely used medicinal perennial woody plant. Obtaining information about the genetic diversity of plant populations is highly important for conservation and germplasm utilization. In this study, we developed single nucleotide polymorphism (SNP) markers derived from chloroplast genomic sequences to identify distinct Korean-specific ecotypes of C. tricuspidata via amplification refractory mutation system (ARMS)-PCR analyses. We performed molecular authentication of twelve C. tricuspidata ecotypes from different regions using DNA sequences in the chloroplast TrnL-F intergenic region. Methods and Results : SNPs were identified based on the results of nucleotide sequence for the intergenic region of TrnL-TrnF gene (chloroplast). Molecular markers were designed for those SNPs with additional mutations on the second base from SNPs for amplification refractory mutation system-polymerase chain reaction (ARMS-PCR). HRM pattern analyses were performed using the Mx3005P QPCR System (Agilent Technologies, CA, USA). Conclusion : We collected 12 individual lines of C. tricuspidata from various region in South Korea and China. Based on the nucleotide sequence in the trnL-trnF intergenic region of these lines, six SNPs and a deletion of 12 bps were identified and 12 individual lines were able to be grouped in one Korean ecotype and two different ecotypes of chinese lines, chinese line 1 and 2. The SNP markers developed in this study are useful for rapidly identifying these specific C. tricuspidata ecotypes collected from different regions.

As a result of inquiring into the analysis consequent on a symptom by research subject, it was found that there were 1 paper (1.5%) which did research for the purpose of rehabilitation of the general public, 26 papers (38.8%) targeting diagnosis-related groups (DRG), and 40 papers (59.7%) targeting social consideration subject. Also, as a result of the inquiry about the frequency & number of times of horticultural therapy program implementation, it was found that 49 papers (73.1%) implemented one time a week, and 45 papers (67.2%) were surveyed as the highest by conducting a total of 11~20 sessions of horticultural therapy programs, In the analysis of horticultural therapy activities by type, plant cultivation activity was found to be the most 506 times, accounting for 41.5%, followed by 297 time crafts activity (24.4%), 213 time floral decoration activity (17.5%), and 203time others activities (16.7%). In cultivation activity, soil-using cultivation activity (25.1%) was found to be lower than the proportion (74.9%) of soiless cultivation (16.4%), crafts activity (24.4%), floral decoration activity (17.5%) and other activities (16.7%). The most used plants in a restricted place like a hospital were found to be in the order of Hedera helix, Chamaedorea elegans, Succulent plant, Syngonium podophyllum, Neofinetia falcata HU, Hoya carnosa (L.f.) R.Br.), Rosmarinus officinalis, and Spathiphyllum spp.

The study was conducted to understand the relationship among university students’ interest in horticulture, psychological well-being and social development and the influence of measured variables. In order to collect data, the surveys were executed by convenience sampling on university students attending four-year universities in Daegu and Gyeongbuk regions of South Korea during the period from July 3 to July 17, 2016. A total of 307 survey results which measured the university students’ interest in horticulture, psychological well-being and social development were analyzed. The results showed that there are differences in the interest in horticulture, psychological well-being, and social development depending on the students’ general characteristics. According to the results analyzed by t-test and one-way ANOVA, the interest in horticulture depending on gender, religion, academic marks, family life satisfaction and school life satisfaction had significant differences showing high interest for the students with religion, good academic marks, high family life satisfaction and school life satisfaction as well as female students. Psychological well-being showed significant differences in academic marks, family life satisfaction and school life satisfaction, while social development displayed significant differences in gender, grade, academic marks, family life satisfaction and school life satisfaction. According to the results analyzed by correlation analysis, there was a significant correlation among university students’ interest in horticulture, psychological well-being and sociality development. Furthermore, regression analysis verified that university students’ interest in horticulture has a positive influence on psychological well-being and social development. The results of this study implies that university students with a higher interest in horticulture have higher levels of psychological well-being and social development.

The purpose of this study was to investigate the improvement of growth in Israeli carp (Cyprinus carpio), and the cross experiment was carried out with two strains of Israeli carp. Four combinations of Israeli carp from Jeonbuk fisheries farm and Songpu mirror carp from Heilong Jiang, China (KK; Jeonbuk ♀ × Jeonbuk ♂, KC; Jeonbuk ♀ × China ♂, CC; China ♀ × China ♂ and CK; China ♀ × Jeonbuk ♂) were developed and reared. Body length, body weight and condition factor were determined at 20, 40, 60 and 170 days post-hatch (DPH). The results showed that there were differences in growth rate of the four groups. Body length of four groups were CK > CC > KC > KK and body weight were CC > CK > KC > KK at 170 DPH. The growth perfomance of four groups were statistically significant difference (P<0.05). During the rearing, CC group had longer length and higher weight at 170 DPH compared to other three groups and also condition factor was highest in the CC group, but there was no significant difference in a survival rate. These results indicated that the growth performance mainly depended upon brooder combination but survival rate could not significantly affect brooder.