• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.276-284
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• 2023

Nitrogen is a major and essential macronutrient for plant growth and development. However, excessive nitrogen application can lead to ecological pollution or greenhouse gas emissions, consequently resulting in climate change. In this study, we used 153 genetic resources of rice to evaluate the effects of the levels of nitrogen application on grain yield and yield-related traits. Significant differences were noted in the yield and yield-related traits of genetic resources between two nitrogen application levels, namely, 4.5 kg/10a (NN: normal nitrogen condition) and 9.0 kg/10a (LN: low-nitrogen condition). Among the tested traits, days to heading (DTH), clum length (CL), grain yield per plant (GYP), number of panicles per plant (NPP), and number of spikelets per panicle (NSP) decreased by 1.8 to 17.9% when the nitrogen application levels decreased from NN to LN. The 1,000-grain weight (TWG) and percentage of ripened grain (PRG) increased by 2.6 to 11.2% under these conditions. Based on nitrogen application levels, two-way analysis of variance (ANOVA) demonstrated significant differences in GYP, NPP, and PRG but not in NSP and TGW. NPP exhibited negative correlations with NSP (-0.44) and TGW (-0.44), and TGW displayed a negative correlation with PRG (-0.34), whereas, GYP exhibited a positive correlation with PRG (0.37) and NSP (0.38). A similar pattern was recorded under the LN condition. NPP, TGW, and PRG were clustered as PA (principle axis) 1 under the LN condition by factor analysis. NSP and GYP were clustered as PA (principle axis) 2. These results demonstrated NPP and NSP as the primary factors contributing to the decrease in grain yield under LN conditions. In conclusion, we selected eight genetic resources that exhibited higher GYP under both NN and LN conditions with higher NPP or NSP. These genetic resources can be considered valuable breeding materials for the adaptation of plants to nitrogen deficiency.

• Journal of Aquaculture
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• v.4 no.1
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• pp.31-66
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• 1991

This paper deals with the reproductive ecology e.g., number of the pre-spawning moults, morphological characteristics of the pre-spawning moult the common moult, daily ration druing a molting cycle mating behavior, structures of spermatozoa and spermatophore, structure of vas deferens, mechanisms of the oviposition and brooding into the egg-chambers, a suitable time for the artificial mating and fertilization, time sequence of the oviposition and brooding into egg-chambers from the copulation, responses to temperature and chlorinity on the egg development and hatching, effect of temperatures on duration of egg development, physical mechanism of the egg hatching, to make an attempt for the artificial spawning and brooding to establish a suitable system of the artificial seedling-production for the aquaculture. 1. Females molted commonly $8{\~}10$ times at an interval of $17{\~}18$ days at $28^{\circ}C,\;3.26\~4.35\%_{\circ}$ while the prespawning moltings were $4{\~}5$ times at an interval of $13{\~}14$ days. The suitable state for artificial copulation was within 14 hours elapsed from the prespawning moltings (most suitable state was within 8 hours). Males discharged a gelatinous spermatophore and placed it on the females sternum during copulation. Oviposition was seen $6{\~}17$ hours after copulation. External fertilization was considered to take place at oviposition. Fertilized eggs held in egg-chambers forming between pleopods were about $5000{\~}6000$ in females those sizes about 6.5 cm in body length. 2. Eggs immediately after oviposition were elliptic shape, measuring $0.58{\times}0.48$ mm up to hatching. Their sizes increased with egg development and finally reached $0.85{\times}0.54$ mm up to hatching. The relationship between the long axis of the egg(Y in U) and days elapsed(X) was expressed as Y= 5.60194 + 0.007358X. The eggs performed superficial cleavage and their cleavage furrows became visible at the 4-daughter-nucleus stage. The eggs showed normal development up to hatching at water temperature range of $22{\~}30^{\circ}C$ (optimum temperature : $26{\~}28^{\circ}C$) and at chlorinity range of $0.00\~6.64\%_{\circ}$ (optimun chlorinity : $2.21{\%}_{\circ}$). The relationship between incubation period (Y in days) and water temperature(X in $^{\circ}C$) could be expressed as Y= 50.803-1.3555X. The eggs hatched $12{\~}13$ days after oviposition at $28.0{\~}28.6^{\circ}C$ 3. The pre-spawning moltings were appreciably different in the morphologic structure from those of common moltings. Breeding setae and dresses were formed on the thoracic regions, abdominal epimerae and the bases of the first to fourth pleopods in order to prepare and support oviposition, transfering and supporting eggs in egg-chambers up to hatching. These supplementary breeding organs were observed only at reproductive seasons.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.1
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• pp.13-16
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• 2001

Plasma levels of sex steroid hormones in rockfish, Sebastes inermis were examined monthly in relation to gonadosomatic index (GSI) under a controlled water temperature and photoperiod, The GSI of a control group (C) in female began to increase from November and reached a maximum in January, Sample fish under a controlled water temperature and photoperiod (Tr) were divided into a responded group (Tr-r) and a un-responded group (Tr-n) by the gonadal maturation condition and GSI. The GSI of females in Tr-r reached a maximum in March. But the female GSI in Tr-n kept lower than 1.2 during the experimental period. No differences in male GSI were noticed between C and Tr. The $estradiol-17\beta$ and testosterone levels of female plasma in Tr reached a maximum in October, later than those in C. In males, these was no difference in 11-ketotestosterone and testosterone between C and Tr. When rockfish was reared in September under the controlled water temperature and photoperiod which were equivalent to those in July, that is two months earlier, the maturation of females was delayed in comparison with C. This finding suggested that delayed maturation in ovary was caused by the secretion of sex steroid hormones in relation to the water temperature and photoperiod of the hypothalamus-pituitary-gonad axis.

• Fashion & Textile Research Journal
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• v.7 no.2
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• pp.143-152
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• 2005

A concept of 'digital' is changing a living pattern of moderners, with having influence on the whole life of modern society. The purpose of this study is arrange the frame of conformity to the 'fashion as culture' by considering the social and cultural phenomena being shown in relation to digital, which is a concept being watched most for the 21st century and by trying to analyze a tendency of digital culture being shown in the modernly fashion design based on this. The digital culture, which is a concept of generalizing the phenomena of interactional changes in the sub-structure being derived by digital technology, is being shown as a tendency of fusionization and globalization, and due to this, the culture of digital nomads is being formed. On the other hand, a tendency of amenity caused by the reaction against the coldly digital technology, is forming one axis of digital culture. As the culture, which experiences the process of a change by digital technology, is reflected even on the fashion, the fusion of technology and the human body, brought about the appearance and the development of the artificial body, by allowing the wearable computer to be introduced to fashion and by being connected directly to the body. This means the expansion of range for fashion. The destruction of a border between space and space, is making an opportunity of forming another ego inside the cyber space, with bringing about the mixed loading between the cyber space and the real space. As the border between the cyber space and the real space is being collapsed, the space of newly self-realization is being created. The collapse of gender is being shown as the pursuit of gender, which is a nomadic concept of not giving priority to anywhere of male gender and female gender. The tendency of sensitive design introduced the sports look as the largely fashion trend. Fascinated with Zen thoughts is leading to a response to the swiftly and coldly social conditions caused by machine. The digital culture by digital technology and the fashion tendency being shown by its influence, meet the needs of self-realization and self-expansion for a human being, and satisfy the needs for the expression of self-identity for a human being, and enable the search for introspection about inner existence inside the self.

• Journal of Agricultural Extension & Community Development
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• v.19 no.2
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• pp.321-353
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• 2012

This study aims to find out ways of improving life satisfaction of rural elderly by investigating their work and leisure activity, two significant axis of the life in later life. For this purpose, researchers and one assistant researcher visited house, senior citizen's center and health center, in order to have interviews with senior citizen above 65, who are currently working in the field. The summary of the research findings are as follows; First, the average size of the farm land which each senior citizen works on is $9,237.92m^2$ and they mostly work for economic reason. During farming season, they work on average 8.62 hour per day. As primary reasons for why farming work is difficult, "insufficient income" was picked. In fact, the average annual income senior citizens earn from farming is about 15.4 million won. 49.1% of sample senior citizens work both on watered farm and farm, and they are engaged in farming 48.82 years on average, showing that most of their lives have been spent on farming. In spite of these difficulties, most senior citizens showed high intention to continue farming work further. Second, senior citizens turn out to spend their leisure time mostly on public leisure activities such as watching TV, hearing radio and gatherings with families, relatives. However, individual activities such as meditation, yoga, drawing and calligraphy turn out to be low because they require foundations to enjoy. Third, senior citizen in rural areas were divided into four groups by farm work and leisure activity: group separated from work and leisure activity(27.09%), group centered to leisure activity(24.42%), group centered to work(23.75%), and group integrated work and leisure activity(23.75%). Fourth, the groups were different depending on demographic characteristics. Namely, male senior citizen, higher educational level, living in elderly couple households, and satisfied with their economic level belonged to the group integrated work and leisure activity. But senior citizen aged above 65 years old and working for their livelihood belonged to the group centered to work, and most of female and senior citizen aged above 80 years old belonged to the group separated from work and leisure activity. Finally, as the result of analysis of differences in life satisfaction according to farm work and leisure activity of senior citizen in rural areas, the group integrated work and leisure activity, and group centered to leisure activity were higher in life satisfaction than the group separated from work and leisure activity, and group centered to work. The above result indicates that life satisfaction of senior citizen depends upon leisure activity rather than work.

• Spatial Information Research
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• v.20 no.4
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• pp.69-82
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• 2012

The purpose of this study was to identify structural properties of C.B.D and to provide direction that required for the plan and its development by analyzing land use patterns and its characteristics in the center of the city. In this study, the future planning elements and detailed land use of Seoul was analyzed, in regard to the spatial structural hierarchy and the function of downtown, by investigation of its current urban spatial structure. First, the characteristic of the land-use for merchandising facilities is that it is developed from west to east along the Jong-ro, Myungdong and Namdaemun, it shows high rate of the facilities along the horizontal axis. The large market area on this district would be the reason to the high rate of mechandising facilities. Second, the characteristic of the land-use for business facilities is that it is highly rated on the area passing through the Sejong-ro and Seoul station. The analysis result of our investigation is that the projects executed by Seoul city such as 'downtown maintenance planning' and 'downtown recreation program' strengthened functions of business and merchandising and promoted downtown shopping, leisure, tourism functions resulting activation of nearby market place and evaluated as maintaing the centrality of downtown Seoul well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.12
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• pp.1106-1113
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• 2013

For patients who have senile mental disorder such as dementia, quantity of excercise and amount of sunlight are important clue for dose and the treatment. Therefore, monitoring health information of daily life is necessary for patients' safety and healthy life. Portable & wearable sensor device and server configuration monitoring data are needed to provide these services for patients. Watch-type device(smart watch) which patients wear and server system are developed in this paper. Smart watch developed includes GPS, accelerometer and illumination sensor, and can obtain real time health information by measuring the position of patients, quantity of exercise and amount of sunlight. Server system includes the sensor data analysis algorithm and web server that doctor and protector can monitor through sensor data acquired from smart watch. The proposed data analysis algorithm acquires quantity of exercise information and detects step count in patients' motion acquired from acceleration sensor and to verify this, the three cases with fast pace, slow pace, and walking pace show 96% of the experimental result. If developed u-Healthcare System for dementia patients is applied, more high-quality medical service can be provided to patients.

• Ocean and Polar Research
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• v.42 no.2
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• pp.115-131
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• 2020

The effective range of surface current data observed by high-frequency radar (HFR) operated in the northern coastal area of Jeju Island by Korea Institute of Ocean Science and Technology was estimated and the distribution and variability of the M₂ tidal current of the Jeju Strait was analyzed. To evaluate the HFR data, the M₂ tidal current corrected from 25 hours current data observed by the Korea Hydrographic and Oceanographic Agency (KHOA) was compared with the M₂ tidal current in the Jeju Strait analyzed from the surface currents of HFR. The reliability of HFR data was confirmed by analyzing the characteristics of the tide components of these two data sets, and the effective range of HFR data was estimated through temporal and spatial analysis. The observation periods of HFR used in the analysis were from 2012 to 2014, and it was confirmed that there is a difference in the effective range of HFR data according to the observation time. During the analysis periods, the difference between the M₂ current ellipses from the data of KHOA and the HFR was greater in the eastern than in the western part of the Jeju Strait, and represented a high reliability in the western and central parts of the Jeju Strait. The tidal current of the Jeju Strait analyzed using the HFR data revealed a seasonal variability a relatively weak in summer and a strong in winter, about a 17% fluctuations between the summer and winter based on the length of the semi-major axis of tidal ellipse. Appraisals and results of regarding the characteristics and seasonal variability of the M₂ tidal current in the Jeju Strait using HFR data have not been previously reported, so the results of this study are considered meaningful.

• Clinical and Experimental Reproductive Medicine
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• v.30 no.1
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• pp.95-103
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• 2003

Objective : To assess and compare the clinical outcomes between GnRH agonist long protocol and GnRH antagonist short protocol in oocyte donation program. Materials and Methods: Of total 18 oocyte donation cycles, controlled ovarian hyperstimulation (COH) were performed with GnRH agonist long protocol and GnRH antagonist short protocol in initial 9 cycles and later 9 cycles, respectively. Oral estradiol valerate and progesterone in oil we re administrated to all recipients for endometrial preparation. Oral estradiol administration was started from donor cycle day 1 after full shut down of gonadal axis with GnRH agonist in patients with ovarian function. Progesterone was injected from oocyte retrieval day of donor initially, then continuously till pregnancy 12 weeks if pregnancy was ongoing. We compared the parameters of clinical outcomes, such as number of the retrieved oocytes, fertilization rate, high grade embryo production rate, clinical pregnancy rate, implantation rate, ongoing pregnancy rate, COH duration, total gonadotropin dose for COH between GnRH agonist long protocol group and GnRH antagonist group. Statistical analysis was performed using Mann-Whitney test, p<0.05 was considered as statistically significant. Results: The number of retrieved oocytes, fertilization rate, high grade embryo production rate, clinical pregnancy rate, implantation rate, ongoing pregnancy rate were $14.89{\pm}7.83$, 81%, 64%, 78%, 31%, 78%, respectively in GnRHa long protocol group and $11.22{\pm}8.50$, 79%, 64%, 67%, 34%, 56%, respectively in GnRH antagonist group. There was no significant differences in parameters of clinical outcomes between 2 groups (all p value >0.05). Duration and total gonadotropin dose for COH were $10.94{\pm}1.70$ days and $43.78{\pm}6.8$ vials in 18 cycles, $12.00{\pm}1.73$ days and $48.00{\pm}6.93$ vials in agonist group, $9.88{\pm}0.78$ days and $39.55{\pm}3.13$ vials in antagonist group, respectively. In GnRH agonist long protocol group, significantly longer duration and higher gonadotropin dose for COH were needed (p=0.012). Conclusion: In oocyte donation program, clinical outcomes from controlled ovarian hyperstimulation with GnRH antagonist were comparable to those from GnRH agonist long protocol group, so controlled ovarian hyperstimulation with GnRH antagonist may be effective as GnRH agonist long protocol. At least there may not be harmful effects of GnRH antagonist on oocyte development and quality.

• Journal of Embryo Transfer
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• v.33 no.3
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• pp.177-183
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• 2018

The identification of biomarkers of a living tissues is essentially required to understand specific functions of the cells. In previous study, we reported IGFBP 3 as one of the putative biomarkers, by showing specific expression at porcine spermatogonial stem cells (SSCs) of early stage of porcine testis. In this study, we analyzed the expression of seven members of IGFBP family (IGFBPs) in SSCs and histological expression pattern of pregnancy-associated plasma protein-A (PAPP-A), which plays a role on the growth promoting enzyme by cleavage of IGFBPs in testis of 5 days old pig. RT-PCR analysis showed that IGFBP 1, 2, 3, 4, and 6 were expressed at high level specifically in porcine SSCs compared with whole testis. We performed immunohisotochemical staining of testis sections with PAPP-A and protein gene product 9.5 (PGP9.5) which are the known biomarkers for SSCs. We were not able to find co-expression of PAPP-A and PGP9.5; PAPP-A was expressed only in Sertoli cells and PGP9.5 expression was confirmed in spermatogonium. Additionally, we were able to confirm the GATA4 expression in Sertoli and Leydig cells as a regulator of Sertoli cell function was not detected PGP9.5 expressing cells, indicating indirect evidence of that cytolocalization of PAPP-A expression is limited in Sertoli cells. These results suggested that the PAPP-A expressed in Sertoli cells may play role on regulation of development and differentiation of testicular cells through the IGF axis in neonatal porcine testis.