• Asia pacific journal of information systems
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• v.24 no.4
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• pp.577-610
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• 2014

Although service innovation is not a new concept, innovation research in general tends to focus on technological innovation by manufacturing firms. With this view, innovation studies focus on product(e.g., goods) and process(e.g., product systems) innovation, ignoring service innovation and its inherent opportunities. Since major economy has been transformed to service economy, service innovation is considered a new effective way to sustain and gain a competitive advantage. Service innovation is no longer regarded merely as a side activity to product innovation; it has become a main research topic in its own right, accompanied by an increasing focus on services. While the number of service innovation studies has increased dramatically in the past 30 years in international research, few studies have been performed in domestic studies because domestic service innovation research began from the middle of 2000. In addition, there are no comprehensive literature reviews describing the evolution of service innovation research in both international and domestic studies because of the heterogeneities of service industry and multidiscipline characteristics of service innovation studies. To bridge this research gap, the purpose of this paper is to perform an extensive literature review and synthesis to enable a critical review of extant research on service innovation and trace its evolution, which will establish a foundation for further studies. By reviewing 169 articles (136 international papers; 33 domestic papers) published between 2000 and 2014 (in past 15 years), primarily in leading service, innovation and management information systems journals, this study analyzes the progression of service innovation research according to the four aspects such as number of studies, topics, methodologies and target industries. Overall, the view of service innovation has evolved, from a complement of traditional product innovation to a multidimensional, all-encompassing concept that entails several functions, both within and outside the firms. The results showed that domestic research still stays at the formation phase of service innovation studies although international research is in the maturity or multidimensional phase. We found increasing recent activities pertaining to service innovation, resulting from the increasing interest in services innovation across various industries and the links of new topics to the service innovation concept in both international and domestic studies. However, the main focus of service innovation research showed a different propensity between international and domestic studies: the former mainly focuses on a much more diversified pattern, emphasizing the linkages between service innovation and business strategy while the latter mainly focuses on the service innovation process(system) and service design. In addition, there are many case studies in domestic studies while many empirical studies in international studies. Domestic studies should increases the understanding of the interplay between service innovation and product innovation within manufacturing firms. Furthermore, rather than focusing on intrinsic distinctions between service innovation and product innovation, researchers should strive to develop and conceptualize service innovation in domestics studies. The present research also provides useful implications for practitioners. First, this study contributes to expand the current understanding of service innovation research by performing an extensive literature review. Second, tracing and comparing the progression and trends of service innovation research between international and domestic studies, this study showed the similarities and differences between them, which provide practical guidance on future research directions and research agenda. Third, this study performed literature review establishing the analysis system in the initial stage and using them to analyze articles, which is leading to explain the research review of service innovation more systematically and objectively. Finally, this study suggests the domestic researchers their future interests and topics of service innovation research.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.507-512
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• 2017

There has been increasing concern regarding misuse of disinfectants and sanitizers such as ethanol, sodium hypochlorite, and hydrogen peroxide for food contact surfaces in the food industry. Examining the efficacy of the concentration of currently used disinfectants and sanitizers is urgently required in the Korean society. This study aimed to develop predictive reduction models for Escherichia coli and Staphylococcus aureus in suspension, as a function of $ClO_2$ (chlorine dioxide) and contact time using response surface methodology. E. coli ATCC 10536 and S. aureus ATCC 6538 (initial inoculum, 8-9 log CFU/mL) in tryptic soy broth were treated with different concentrations of $ClO_2$ (5, 20, and 35 ppm) for different contact times (1, 3, and 5 min) following a central composite design. The polynomial reduction models for $ClO_2$ on E. coli and S. aureus were developed under the clean condition. E. coli reduction by 35 ppm $ClO_2$ for 1, 3, and 5 min was 2.49, 2.70, and 3.65 log CFU/mL, respectively. Also, S. aureus reduction by 35 ppm $ClO_2$ for 1, 3, and 5 min was 4.59, 5.25, and 5.81 log CFU/mL, respectively. The predictive response polynomial models developed were $R=0.43231-0.056492^*X_1-0.097771^*X_2+9.24167E-003^*X_1^*X_2+3.06333E-003^*X_1{^2}$ ($R^2=0.98$) on E. coli and $R=1.10542-0.20896^*X_1-0.046062^*X_2+8.30000E-003^*X_1^*X_2+8.73300E-003^*X_1{^2}$ ($R^2=0.99$) on S. aureus, where R was the bacterial reduction (log CFU/mL), $X_1$ was the concentration and $X_2$ was the contact time. Our predictive reduction models should be validated in developing the optimal concentration and contact time of $ClO_2$ for inhibiting E. coli and S. aureus on food contact surfaces.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.387-393
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• 2021

In this study, finite element analysis was performed to evaluate a method of increasing the fatigue life of the pipe connection structure commonly used in the topside structure of offshore platforms. MSC Patran/Nastran, a commercial analysis program, was used, and the critical structural model was selected from the global analysis. To realize the stress concentration phenomenon according to the load, modeling using 8-node solid elements was implemented. The main loads were considered to be two lateral loads and a tensile load on a diagonal pipe. To check the hotspot stress at the main location, a 0.01 mm dummy shell element was applied. After calculating the main stress at the 0.5-t and 1.5-t locations, the stress generated in the weld was estimated through extrapolation. In some sections, this stress was observed to be below the fatigue life that should be satisfied, and reinforcement was required. For reinforcement, a bracket was added to reduce the stress concentration factor where the fatigue life was insufficient without changing the thickness or diameter of the previously designed pipe. Regarding the tensile load, the stress in the bracket toe increased by 23 %, whereas the stress inside and outside of the pipe, which was a problem, decreased by approximately 8 %. Regarding the flexural load, the stress at the bracket toe increased by 3 %, whereas the stress inside and outside of the pipe, which was also a problem, decreased by approximately 48 %. Owing to the new bracket reinforcement, the stress in the bracket toe increased, but the S-N curve itself was better than that of the pipe joint, so it was not a significant problem. The improvement method of fatigue life is expected to be useful; it can efficiently increase the fatigue life while minimizing changes to the initial design.

• Korean Journal of Construction Engineering and Management
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• v.20 no.4
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• pp.22-33
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• 2019

The government has steadily revised and developed laws and systems for activating remodeling of apartments in response to the problems of aged apartments. However, despite such efforts, remodeling has yet to be activated. For many reasons, this study noted that there were no tools for reasonable profitability judgements and decision making in the preliminary stages of the remodeling project. Thus, the feasibility evaluation model was developed. Generally, the profitability judgements are made after the conceptual design. However, decisions to drive remodeling projects are made at the preliminary stage. So a feasibility evaluation model is required at the preliminary stage. Accordingly, In this study, a feasibility evaluation model was developed for determining preliminary stage profitability. Construction costs, business expenses, financial expenses, and generally sales revenue were calculated using the initial available information and remodeling variables derived through the existing cases. Through this process, we developed an algorithm that can give an overview of the return on investment. In addition, the preliminary stage feasibility evaluation model developed was applied to three cases to verify the applicability of the model. Although applied in three cases, the difference between the model's forecast and actual case values is less than 5%, which is considered highly applicable. If cases are expanded in the future, it will be a useful tool that can be used in actual work. The feasibility evaluation model developed in this study will support decision making by union members, and if the model is applied in different regions, it will be expected to help local governments to understand the size of possible remodeling projects.

• Journal of Nutrition and Health
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• v.52 no.4
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• pp.342-353
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• 2019

Purpose: The Dietary Reference Intakes for Koreans (KDRIs) suggest that the goal for the intake of sodium should be less than 2,000 mg, which is thought to be infeasible to achieve when eating the typical Korean diet. This study aimed to obtain the new intake goals for sodium with improved feasibility to achieve, and also to design optimized food intake patterns for Korean adults by performing linear programming. Methods: The data from a one day 24-hour dietary recall of the 2010 ~ 2014 Korea National Health and Nutrition Survey were used to quantify food items that Korean adults usually consumed. These food items were categorized into seven groups and 24 subgroups. The mean intakes and intake distributions of the food groups and the food subgroups were calculated for eight age (19 ~ 29, 30 ~ 49, 50 ~ 64, and over 65 years old) and gender (male and female) groups. A linear programming model was constructed to minimize the difference between the optimized intakes and the mean intakes of the food subgroups while meeting KDRIs for energy and 13 nutrients, and not exceeding the typical quantities of each of the food subgroups consumed by the respective age and gender groups. As an initial solution of the linear programming, the optimized intake of seasonings, including salt, was calculated as 0 g for all the age and gender groups when the sodium constraint was inserted not to exceed 2,000 mg. Therefore, the sodium constraint was progressively increased by 100 mg until the optimized intake of seasoning was obtained as the values closest to the $25^{th}$ percentile of the intake distribution of seasonings for the respective age and gender groups. Results: The optimized food intake patterns were mathematically obtained by performing linear programming when the sodium constraint values were 3,600 mg, 4,500 mg, 4,200 mg, 3,400 mg, 2,800 mg, 3,100 mg, 3,100 mg, and 2,500 mg for the eight age and gender groups. Conclusion: The optimized food intake patterns for Korean adults were designed by performing linear programming after increasing the sodium constraint values from 2,000 mg to 2500 ~ 4,500 mg according to the age and gender groups. The resulting patterns suggest that current diets should be modified to increase the intake of vegetables for all the groups, milk/dairy products for the female groups, and fruits for the female groups except for the females aged 50 ~ 64 years.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.4-25
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• 2013

Goli-su is the innovative special kind of the embroidery technique, which combines twining and interlacing skill with metal technology and makes the loops woven to each other with a strand. The loops floating on the space of the ground look like floating veins of sculpture and give people the feeling of the openwork. This kind of characteristic has some similarities with the lacework craft of Western Europe in texture and technique style, but it has its own features different from that of Western Europe. It mainly represents the splendid gloss with metallic materials in the Embroidered cloth, such as gold foil or wire. In the 10th century, early days of Goryo, we can see the basic Goli-su structure form of its initial period in the boy motif embroidery purse unearthed from the first level of Octagonal Nine-storied Pagoda of Woljeong-sa. In the Middle period of Joseon, there are several pieces of Goli-su embroidered relic called "Battle Flag of Goryo", which was taken by the Japanese in 1592 and is now in the Japanese temple. This piece is now converted into altar-table covers. In 18~19th century, two pairs of embroidered pillows in Joseon palace were kept intact, whose time and source are very accurate. The frame of the pillows was embroidered with Goli-su veins, and some gold foil papers were inserted into the inside. The triangle motif with silk was embroidered on the pillow. The stitch in the Needle-Looped embroidery is divided into three kinds according to comprehensive classification: 1. Goli-su ; 2. Goli-Kamgi-su ; 3. Goli-Saegim-su. From the 10th century newly establishing stage to the 13th century, Goli-su has appeared variational stitches and employed 2~3 dimensional color schemes gradually. According to the research of this thesis, we can still see this stitch in the embroidery pillow, which proves that Goli-suwas still kept in Korea in the 19th century. And in terms of the research achievement of this thesis, Archetype technology of Goli-su was restored. Han Sang-soo, Important Intangible Cultural Heritage No. 80 and Master of Embroidery already recreated the Korean relics of Goli-su in Joseon Dynasty. The Needle-Looped embriodery is the overall technological result of ancestral outstanding Metal craft, Twining and Interlacing craft, and Embroidery art. We should inherit, create, and seek the new direction in modern multi-dimensional and international industry societyon the basis of these research results. We can inherit the long history of embroidering, weaving, fiber processing, and expand the applications of other craft industries, and develop new advanced additional values of new dress material, fashion technology, ornament craft and artistic design. Thus, other crafts assist each other and broaden the expressive field to pursue more diversified formative beauty and beautify our life abundantly together.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.2
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• pp.37-45
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• 2022

A simplified model using the lifetime distribution has been presented to estimate the Mean Residual Life (MRL) of rubble-mound breakwaters, which is not like a stochastic process model based on time-dependent history data to the cumulative damage progress of rubble-mound breakwaters. The parameters involved in the lifetime distribution can be easily estimated by using the upper and lower limits of lifetime and their likelihood that made a judgement by several experts taking account of the initial design lifetime, the past sequences of loads, and others. The simplified model presented in this paper has been applied to the rubble-mound breakwater with TTP armor layer. Wiener Process (WP)-based stochastic model also has been applied together with Monte-Carlo Simulation (MCS) technique to the breakwater of the same condition having time-dependent cumulative damage to TTP armor layer. From the comparison of lifetime distribution obtained from each models including Mean Time To Failure (MTTF), it has found that the lifetime distributions of rubble-mound breakwater can be very satisfactorily fitted by log-normal distribution for all types of cumulative damage progresses, such as exponential, linear, and logarithmic deterioration which are feasible in the real situations. Finally, the MRL of rubble-mound breakwaters estimated by the simplified model presented in this paper have been compared with those by WP stochastic process. It can be shown that results of the presented simplified model have been identical with those of WP stochastic process until any ages in the range of MTT F regardless of the deterioration types. However, a little of differences have been seen at the ages in the neighborhood of MTTF, specially, for the linear and logarithmic deterioration of cumulative damages. For the accurate estimation of MRL of harbor structures, it may be desirable that the stochastic processes should be used to consider properly time-dependent uncertainties of damage deterioration. Nevertheless, the simplified model presented in this paper can be useful in the building of the MRL-based preventive maintenance planning for several kinds of harbor structures, because of which is not needed time-dependent history data about the damage deterioration of structures as mentioned above.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.19-29
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• 2022

The result of a questionnaire survey conducted on fishermen using coastal fish traps shows that fall accidents during trap dropping and pulling constitute the highest proportion of accidents at 42.1 %, whereas slipping accidents on the deck or stricture accidents to the body due to the trap winding device constitute 21.1 % each. In addition, 53.2 % of all surveyed subjects responded that trap pulling is the most dangerous task, followed by fish sorting 33.8 %, and trap dropping 9.1 %. As for the main items requested by fishermen for improving the trap winding device, 36.8 % indicated a method to easily lift the trap from the water to the work deck, and 31.6 % indicated a method to overcome the rope tension and prevent slip when pulling the trap to reduce the accidents. The small trap fishing vessel winding device proposed herein can increase the winding force by strengthening the rope contact area and friction coefficient via an appropriate contact angle between the driving roller of the winding device and the rope. When the contact angles between the driving roller and the rope are 1°, 5°, 9°, 14° and 19°, the rope tension showed a difference according to each contact angle. When the contact angle is 9°, the rope tension is the highest at 392.62 kgf. Based on these experimental results, a prototype winding device is manufactured, and 25 traps are installed on a rope with a total length of 100 m at 4 m intervals in the sea, and then the rope tension is measured during trap pulling. As a result, the rope tension increases rapidly at the initial stage of trap pulling and shows the highest value of 31.89 kgf, which subsequently decreases significantly. Therefore, it is appropriate to design the winding force of a small trap fishing vessel winding device based on the maximum tension value of the rope specified at the beginning of the trap pulling operation.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.101-114
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• 2008

Pressurized grouting is a common technique in geotechnical engineering applications to increase the stiffness and strength of the ground mass and to fill boreholes or void space in a tunnel lining and so on. Recently, the pressurized grouting has been applied to a soil-nailing system which is widely used to improve slope stability. Because interaction between pressurized grouting paste and adjacent ground mass is complicated and difficult to analyze, the soil-nailing design has been empirically performed in most geotechnical applications. The purpose of this study is to analyze the ground behavior induced by pressurized grouting paste with the aid of laboratory model tests. The laboratory tests are carried out for four kinds of granitic residual soils. When injecting pressure is applied to grout, the pressure measured in the adjacent ground initially increases for a while, which behaves in the way of the membrane model. With the lapse of time, the pressure in the adjacent ground decreases down to a value of residual stress because a portion of water in the grouting paste seeps into the adjacent ground. The seepage can be indicated by the fact that the ratio of water/cement in the grouting paste has decreased from a initial value of 50% to around 30% during the test. The reduction of the W/C ratio should cause to harden the grouting paste and increase the stiffness of it, which restricts the rebound of out-moved ground into the original position, and thus increase the in-situ stress by approximately 20% of the injecting pressures. The measured radial deformation of the ground under pressure is in good agreement with the expansion of a cylindrical cavity estimated by the cavity expansion theory. In-situ test revealed that the pullout resistance of a soil nailing with pressurized grouting is about 36% larger than that with regular grouting, caused by grout radius increase, residual stress effect, and/or roughness increase.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.2
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• pp.68-81
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• 2014

This study was conducted to identify the spacialty, to illuminate the existence and values of Myeongwoldae(明月臺) and Forest Myeongwol, and to suggest the sustainable usage, preservation and management plans with the purpose of ecological and cultural landscaping characteristic and value identification. The result of the study is as follows. Castle Myeongwol and Port Myeongwol shows the status of Hallim-eup Myeongwol District which is the administrative center of western Jeju as well as is the fortress. Building Wolgyejeongsa and School Woohakdang, the head temple of education and culture, located in Myeongwol District represents the spaciality of Myeonwol-ri which was the center of education. Stand Myeongwol is one of the most representative Confucian cultural landscapes in Jeju Island and the field of communion with nature where scholars enjoy poetries, nature, changgi(Korean chess), and go in the Joseon Dynasty period. It was found that the current relics of Myeongwoldae was recovered through the maintenance project conducted by Youth Group Myeongwol composed with Hongjong-si(洪鍾時) as the center during the Japanese colonial era in 1931. It seems that the stonework of Myeongwoldae composed of three levels in the order of square, octagon, and circle based on the heaven-man unity theory of Confucianism and the octagon in the middle is the messenger of Cheonwonjibang(天圓地方), in other words, between the square-shaped earth and the circle-shaped sky. It is assumed that both Grand Bridge Myeongwol and Bridge Myeongwol were constructed as arched bridges in early days. Bridge Myeongwol is the only arched bridge remaining in Jeju Island now, which has the modern cultural heritage value. In Forest Myeongwol, 97 taxa of plants were confirmed and in accordance with 'Taxonomic Group and Class Criteria of Floristic Specific Plants', eight taxa were found; Arachniodes aristata of FD IV and Ilex cornuta, Piper kadsura, Litsea japonica, Melia azedarach, Xylosma congestum, Richosanthes kirilowii var. japonica, Dichondra repens, Viburnum odoratissimum var. awabuki of FD III. Otherwise, 14 taxa of naturalized plants including Apium leptophylihum which is imported to Jeju Island only were confirmed. In Forest Myeongwol, 77 trees including 41 Celtis sinensis, 30 Aphananthe aspera, two Wylosma congestum, a Pinus densiflora, a Camellia japonica, a Melia azedarach, and an Ilex cornuta form a colony. Based on the researched data, the preservation and plans of Myeongwoldae and Forest Myeongwol is suggested as follows. Myeongwoldae, Bridge Myeongwol, and Forest Myeongwol should be managed as one integrated division. Bridge Myeongwol, an arched bridge which is hard to be found in Jeju Island is a high-standard stonework requiring long-term preservation plans. Otherwise, Grand Bridge Myeongwol that is exposed to accident risks because of deterioration and needs safety diagnosis requires measures according to the result of precise safety diagnosis. It is desirable to restore it to a two-sluice arched bridge as its initial shape and to preserve and use it as a representative local landmark with Stand Myeongwol. In addition, considering the topophsis based on the analysis result, the current name of Jeju Special Self-Governing Province Monument No. 19 'Myoengwol Hackberry Colony' should change to 'Myeongwol Hackberry-Muku Tree Colony'. In addition, the serial number system which is composed without distinction of hackberry and muku tree should be improved and the regular monitoring of big and old trees, specific plants, and naturalized species is required.